View Full Version : Project Featherweight
Robb Jensen
10-15-09, 07:32
This is a carbine I built up for my wife. The goal was to make an extremely lightweight non-SBR. This wasn't meant to be a heavy use gun high round count gun but rather one that would always be near while traveling and that which is easily handled. It weighs 87ozs, aka 5.43lbs. I'm going to coat the barrel, both receivers, receiver extension and Troy tube in Norrels FDE and then Krylon everything. I may replace the front sight with a DD fixed front and use a Surefire X300 in front of it.
Components:
RRA 1x8 16" midlength barrel cut to 14.5" and turned down to .565" barrel profile, chamber reamed from .223 Wylde to 5.56 mm NATO, FSB shaved and then cut in half only using the rear half, PWS FSC556 pinned/welded for 16-1/16th" overall barrel length.
CMT upper receiver with no dust door or forward assist. I'm using a delrin plug from ADCO to plug the upper receivers hole for the forward assist. JP LMOS carrier (no forward assist cuts) with BCM bolt, cam pin and firing pin. BCM standard charging handle. Double Star lower with Stag lower parts kit. Colt grip and Colt CAR stock. VLTOR receiver extension, BCM castle nut and end plate, CMT CAR buffer and spring. Magpul MOE triggerguard and MBUS sights. Aimpoint H1 in a Daniel Defense Micro mount.
http://img.photobucket.com/albums/v408/gotm4/gunpics/projectfeatherweight2.jpg
http://img.photobucket.com/albums/v408/gotm4/gunpics/projectfeatherweight3.jpg
That is one slick looking carbine! I like it, nice job.
That's incredible! Nice work
Interesting, in that I'm thinking of doing something similar. Couple of questions:
1) Any concerns with turning down stainless that thin? I know you say it's not a "heavy use" gun but any reason you went stainless and not 4150?
2) I think you posted it before but I can't find it. Have a weight on your uber-shaved FSB? I'm wanting to compare the weight of the TRX setup with shaved FSB to a standard handguard and FSB setup.
I think you posted it before but I can't find it. Have a weight on your uber-shaved FSB?
Here you go:
I weighed some stuff:
FSB = 4.9oz
my ultra low pro shaved FSB = 1.6 oz.
cut in 1/2 shaved FSB = 0.7oz
M16 carrier w/key = 9.7oz
JP LMOS carrier w/key = 6.7oz
I forget the actual weights but interesting enough the one A1 handguard ring was 1/2 the weight of an A2 delta ring.
Robb Jensen
10-15-09, 14:25
Interesting, in that I'm thinking of doing something similar. Couple of questions:
1) Any concerns with turning down stainless that thin? I know you say it's not a "heavy use" gun but any reason you went stainless and not 4150?
2) I think you posted it before but I can't find it. Have a weight on your uber-shaved FSB? I'm wanting to compare the weight of the TRX setup with shaved FSB to a standard handguard and FSB setup.
I used that barrel just because I happened to have sitting in my toolbox not mounted on a gun. It was .650" under the rail behind the gas block, shaved FSB at .750" at the gas seat and .740" forward of it. 4150 chrome lined I'm sure would hold up a lot better in the long run.
I sighted it in the other night and then cranked off 30 rounds in controlled pairs afterward....it gets warm but I've gotten .750" barrels much hotter doing the same thing. When I find it I'll bring my digital pyrometer to the range to measure the heat at the barrel. I went with .565" profile since .550" is what Randall called featherweight. I just wanted to be a tad heavier. By non-heavy use I mean this isn't something I'd use for doing a "break contact" drill (7-8 mags fired rapidly on full auto).
Robb Jensen
10-15-09, 14:26
Just got 2 DD fixed front sights today, interesting discovery:
DD front sight weighs 1.1oz
Magpul MBUS front sight weighs 1.3oz (w/o the roll pin that gets inserted after zeroing)
SeriousStudent
10-15-09, 20:48
Okay, Robb, so tell us the stock number at VA Arms so we can order one. :D
Very nice carbine. And even when you add an X300, it's still under six pounds!
Robb Jensen
10-15-09, 20:50
Okay, Robb, so tell us the stock number at VA Arms so we can order one. :D
Very nice carbine. And even when you add an X300, it's still under six pounds!
It's was just a concept after the work I did for Byron. He started it! :D
SeriousStudent
10-15-09, 21:12
Well, it looks very efficient. I'm in the process of building a carbine like that for my daughter's 18th birthday present.
I've been thinking about one of those BCM lightweight middy barrels for it. Combined with an upper like this, it would be very soft-shooting and still lightweight.
Thanks! :)
gruntinhusaybah
10-17-09, 20:37
its a good looking rifle and good concept, how does it shoot?
Does it get hot with the thinner bbl?
whats the weight difference between the standard CH and a Gunfighter?
weight difference between the CAR stock and a MOE/CTR?
thanks
LonghunterCO
10-17-09, 20:51
Can not wait to see it painted. What did the JP LMOS carrier save you in weight?
Robb Jensen
10-17-09, 21:32
Can not wait to see it painted. What did the JP LMOS carrier save you in weight?
About 3oz.
This is a really cool idea. Looks pretty well executed; please let us know how it shoots!
What kind of rail is that, and how do you like it?
-B
Robb Jensen
10-18-09, 13:01
It's a Troy 11" TRX BattleRail.
Updated pic. This morning I changed out the sights and put on a set of fixed Daniel Defense sights and a SureFire X300 mounted at 12 o'clock in front of the front sight.
http://img.photobucket.com/albums/v408/gotm4/gunpics/updatedfeatherweight.jpg
The Dumb Gun Collector
10-18-09, 18:25
NICE! I like it.
What if you drilled out the Aimpoint mount? How about an A1 grip? Perhaps a few holes in the stock and maybe the receiver extension?
A very interesting exercise.
LonghunterCO
10-18-09, 18:39
It's a Troy 11" TRX BattleRail.
Updated pic. This morning I changed out the sights and put on a set of fixed Daniel Defense sights and a SureFire X300 mounted at 12 o'clock in front of the front sight.
http://img.photobucket.com/albums/v408/gotm4/gunpics/updatedfeatherweight.jpg
Weight ?
Are you concerned about shooting NATO pressure ammunition with the LMOS carrier? Is that a potential mis-match?
Robb Jensen
10-18-09, 20:19
Are you concerned about shooting NATO pressure ammunition with the LMOS carrier? Is that a potential mis-match?
No. In a CAR length maybe, but no problem in a midlength.
Very cool! I have been thinking of a very similar build - nice to see it out of the minds eye.
I recently saw this carbine. It's slick and GotM4 did everything he could to shave weight.
GotM4 built me an upper with a VTAC TRX 11" and CMMG 14.5" lightweight midlength with pinned Phantom. It's 5 lbs 9 oz w/o optics.
That is an outstanding blaster man.
JohnVassilakos
10-29-09, 15:52
Very cool. I think I might attempt something like this on my next build.
Did you look at the carbon uppers/lowers? I know BM used to build a carbon 15 that weighed around 4.3-4.5 lbs...not sure how well they hold up though.
longrange18
10-30-09, 04:54
What about a Les Baer upper with no forward assist at all?
Robb Jensen
10-30-09, 06:14
Weight ?
5.66lbs (90.6ozs)
Very cool. I think I might attempt something like this on my next build.
Did you look at the carbon uppers/lowers? I know BM used to build a carbon 15 that weighed around 4.3-4.5 lbs...not sure how well they hold up though.
I thought about those but haven't seen one that actually ran well. The barrels have proprietary barrel extensions so you have to use their barrels too.
What about a Les Baer upper with no forward assist at all?
I thought of using an upper that didn't have a forward assist but since I already had the flat top that I used which I had scavenged all the parts for another project. The ADCO forward assist plug was $5 IIRC.
Very nice rifle. You gave me plenty of ideas for a "kid" build.
QuietShootr
11-03-09, 20:32
My wife would still bitch about the weight.
JohnVassilakos
11-03-09, 21:30
My wife would still bitch about the weight.
Paint it her favorite color(s).
Women tend to overlook something like the weight of a rifle if they like the looks of it (to a certain extent - obviously they won't care what color a .50 BMG is, they're damn heavy).
BretShooter
11-06-09, 14:51
Paint it her favorite color(s).
A color match for shoes and purse?
j/k
JohnVassilakos
11-06-09, 21:51
A color match for shoes and purse?
j/k
Hey, whatever it takes to get them shooting.
I let my wife hold my KISS rifle earlier and she complained that it was heavy. It's a basic 16" gun with no bells and whistles, not even an optic.
Of course, it was right after she had been practicing dry firing with her Ruger LCP so ANYTHING would have seemed heavy compared to that.
BretShooter
11-07-09, 01:47
It may seem counter intuitive, and it is easy to reverse, but try adding some weight to the rear, be it heavier stock, buffer, whatever. It can give the feel of a lighter rifle because it feels less front heavy.
And I agree. Whatever gets em shooting or at least letting you do it!
I'm going to coat the barrel, both receivers, receiver extension and Troy tube in Norrels FDE and then Krylon everything.
I'm curious, why would you do it in Norrels and then throw Krylon on top?
These lightweight builds keep drawing my attention. I keep thinking that one of the upcoming BCM lightweight uppers combined with the Troy TRX or the Troy/Viking Tactics version would be a great lightweight build...
decodeddiesel
11-12-09, 10:30
Robb, have you thought about possibly replacing the X300 with a Streamlight TLR-3?
I have been using one on an M&P9C for a while now and have been impressed with it's small size and light output. Durability seems on par with the TLR-1 and such, but it only weighs 2.32 ounces.
http://www.streamlight.com/news_let/09_q2/tlr3.html
Is the TLR-3 tailpiece similar to the TLR-1? I can't find any back end pics after a quick search.
decodeddiesel
11-13-09, 00:25
Is the TLR-3 tailpiece similar to the TLR-1? I can't find any back end pics after a quick search.
Yes it is very similar, I will try to take some pics when I get a chance.
Thanks! I'm looking for a small LED weaponlight, and this is the first I've heard of the -3.
Dan Goodwin
12-01-09, 06:19
GotM4,
Been mulling an ultralight AR for a walking varminter some time, but keep backburnering for other things/bills. With some decent lowers going for under $100 these days I may get off my butt.
My goal is a 20-in A1 profile with the lightest fixed stock available and a very light fixed 4 or 6X scope. A faster twist might be better though TSX bullets make heavier bullets not necessary.
While this could be pressed into service in a fight it is to be mostly a hunting gun.
What would your recipe/blueprint be to get something like that under 6 lbs.?
Robb Jensen
12-01-09, 06:23
GotM4,
Been mulling an ultralight AR for a walking varminter some time, but keep backburnering for other things/bills. With some decent lowers going for under $100 these days I may get off my butt.
My goal is a 20-in A1 profile with the lightest fixed stock available and a very light fixed 4 or 6X scope. A faster twist might be better though TSX bullets make heavier bullets not necessary.
While this could be pressed into service in a fight it is to be mostly a hunting gun.
What would your recipe/blueprint be to get something like that under 6 lbs.?
I think that would be pretty hard to reach. Most scopes w/mounts are going to be at least 1lb. You might look at a 18-20" ABS (http://home.windstream.net/mdegerness/) carbon fiber barrel to save some weight typically these are 1-2lbs lighter than a standard barrel. For a lower I would go with a Cav Arms lower (A1 length). JP LMOS carrier and LMOS rifle buffer and spring.
Robb, have you thought about possibly replacing the X300 with a Streamlight TLR-3?
I have been using one on an M&P9C for a while now and have been impressed with it's small size and light output. Durability seems on par with the TLR-1 and such, but it only weighs 2.32 ounces.
http://www.streamlight.com/news_let/09_q2/tlr3.html
I did install a TLR-3 just last week. It's is a little lighter and a little taller than the X300. So you do see a tiny bit more of the light when using the iron sights. Not a big deal on this gun since it's primary sight is the Aimpoint.
http://img.photobucket.com/albums/v408/gotm4/gunpics/projectfeatherweight024.jpg
http://img.photobucket.com/albums/v408/gotm4/gunpics/projectfeatherweight026.jpg
http://img.photobucket.com/albums/v408/gotm4/gunpics/projectfeatherweight029.jpg
LonghunterCO
12-01-09, 07:33
The Cav arms lower uses a carbine buffer/spring setup.
Robb Jensen
12-01-09, 07:40
The Cav arms lower uses a carbine buffer/spring setup.
I had forgotten that, with that I'd recommend a CAR buffer and standard rate chrome silicon buffer spring. I like the Brownells springs.
Starting to look a lot like what I'm planning once the BCM midlength .625 14.5" comes out.
Robb, any thoughts on tapered single-shield cavarms handguards with Streamlight plastic rail attached and stock FSB vs. Troy extreme, ultra-shaved FSB and DD front sight (as you have) in terms of weight of one setup vs the other?
Dan Goodwin
12-01-09, 16:24
After checking that barrel site, pretty sure turning down a regular barrel is preferrable for financial reasons!
Hadn't really considered the CavArms all plastic lower+stock, but A1 length is desireable.
Which drop in match trigger would be most desireable for this hunting gun?
I use standard Colt trigger groups in my work guns, but the idea of a crisp, light trigger has appeal for this application.
Robb Jensen
12-01-09, 20:10
Starting to look a lot like what I'm planning once the BCM midlength .625 14.5" comes out.
Robb, any thoughts on tapered single-shield cavarms handguards with Streamlight plastic rail attached and stock FSB vs. Troy extreme, ultra-shaved FSB and DD front sight (as you have) in terms of weight of one setup vs the other?
The tapered CAR handguards are quite light but I think that offset would be cancelled out by the weight of the FSB and handguard cap. The Troy rail is extremely lightweight plus you'll have to factor in the weight of the delta ring, snap ring and weld spring. I'll weigh bbl nut, delta ring, snap ring, weld spring, FSB w/2 taper pins, front sight post, detent and spring and a handguard cap tomorrow. I can't remember what a 11" Troy rail weighs with it's bbl nut. I'm fairly certain the ultra low shave w/pins, Troy rail with it's bbl nut and a DD front sight is lighter. I'm certain you'll like the BCM .625" bbl. I have two BCM guns I use for 3gun now and both are excellent, very high quality stuff.
Curious.....what's the approx. cost to have Adco do a barrel turn like that?
Robb Jensen
01-24-10, 21:46
Curious.....what's the approx. cost to have Adco do a barrel turn like that?
One of my 3gun sponsors did the barrel profiling (Drew at W.A.R. Rifles).
Starting to look a lot like what I'm planning once the BCM midlength .625 14.5" comes out.
Robb, any thoughts on tapered single-shield cavarms handguards with Streamlight plastic rail attached and stock FSB vs. Troy extreme, ultra-shaved FSB and DD front sight (as you have) in terms of weight of one setup vs the other?
I was thinkin' the same thing (BCM 14.5" LW Middy), but with MOE handguards. Have to wait and see once both are available.
piggly_wiggly
01-24-10, 22:26
My wife would still bitch about the weight.
Been there, heard that. Made a 14.5" .625-barrel blaster for momma back when JP was making oversized vented handguards... "It's too heavyyyyyyy"...
:rolleyes:
Fast forward a decade and I hand her a Scout M1A at the Springfield booth at SHOT and ask her what she thinks... "Not bad..."
:D
I was confused but I wasn't gonna say a word. Some women must get stronger with age- lol.
GotM4, that is a sweeeet setup. If you want to try an uber lightweight light option, I'm interested in trying the new S&W Flashlights 3V weaponlight the
same way you have yours setup. Should be shorter and significantly lighter than the TL3 or X300.
I keep liking this build :)
Is there a reason most people don't cut the chopped down FSB in half as you did (other than maybe leaving an un-parked band of barrel exposed)?
Robb Jensen
01-28-10, 05:20
I keep liking this build :)
Is there a reason most people don't cut the chopped down FSB in half as you did (other than maybe leaving an un-parked band of barrel exposed)?
That's probably the main reason plus that way it would have two pins instead of one. On mine it didn't matter since it's a stainless barrel. I have a bunch of new pins and used a new one which fit extremely tight.
I've cut down FSBs before and always kept the two pins for redundancy.
I wonder if it would be possible to install a set-screw in the bottom of the remaining "band" of the FSB and dimple the barrel for it, giving you a little extra security for the paranoid like me. Although on a pencil barrel the pin hole in the barrel itself tends to break through the outer portion of the barrel so I guess there wouldn't be any place for the screw. Maybe do one on the side...
That is awesome.. Im sure the wife is pleased..
If I may make just one small suggestion.. IMO (this is only me, Im a little different) no rifle especially an evil rifle is truly complete with a proper mag picture.. Now since this is for the wife! I have just the thing in mind, of course you can also change up the color too..
http://i264.photobucket.com/albums/ii195/TDC57/heart_skull_tattoo_design_by_Micawb.jpg
Or perhaps?
http://i264.photobucket.com/albums/ii195/TDC57/skul9.jpg
Just a thought..
I'll be more than happy to help answer any questions you might have and will even send you the stencil if you want / decide to give it try..
link
Ned Christiansen
01-30-10, 11:47
Well I think you picked the right rail. I had one for an article in SWAT Magazine and although I did not put it on the scale and compare it to a bunch of others, I felt it was the lightest I'd handled.
That thing needs an aluminum flash-hider..... or just an A-1, I'll bet that'll be an ounce lighter than what's on it......
Robb Jensen
01-30-10, 12:42
Well I think you picked the right rail. I had one for an article in SWAT Magazine and although I did not put it on the scale and compare it to a bunch of others, I felt it was the lightest I'd handled.
That thing needs an aluminum flash-hider..... or just an A-1, I'll bet that'll be an ounce lighter than what's on it......
Ned I weighed a three prong old school flash hider, an A1 and A2 and the FSC556 was the same weight as the A1 and actually a little lighter than the three prong and A2. And since the FSC556 works as a comp and a flash hider I naturally thought it was a good fit.
1811tactikool
02-05-10, 10:46
Nice Build!
I'm interested in a lightweight build and have some questions. Anyone know where I could get a Colt CAR stock? I did find these two, any opinions?
C.A.R. Stock, Complete with buffer & spring (Collapsable) (http://www.ar15products.net/itm00488.htm), ar15products.net
C.A.R. Auminum Stock, Complete with buffer & spring (Collapsible) (http://www.ar15products.net/itm00490.htm), ar15products.net
Is the CAR stock lighter than the CTR?
Are these two #1 and #2 with respect to lightest stock, the CAR being the lightest, CTR second lightest?
Robb Jensen
02-05-10, 13:23
I'm interested in a lightweight build and have some questions. Anyone know where I could get a Colt CAR stock? I did find these two, any opinions?
C.A.R. Stock, Complete with buffer & spring (Collapsable) (http://www.ar15products.net/itm00488.htm), ar15products.net
C.A.R. Auminum Stock, Complete with buffer & spring (Collapsible) (http://www.ar15products.net/itm00490.htm), ar15products.net
Is the CAR stock lighter than the CTR?
Are these two #1 and #2 with respect to lightest stock, the CAR being the lightest, CTR second lightest?
Yes. The plastic CAR stock is the lightest I've ever seen.
1811tactikool
02-05-10, 13:35
Been there, heard that. Made a 14.5" .625-barrel blaster for momma back when JP was making oversized vented handguards... "It's too heavyyyyyyy"...
:rolleyes:
Fast forward a decade and I hand her a Scout M1A at the Springfield booth at SHOT and ask her what she thinks... "Not bad..."
:D
I was confused but I wasn't gonna say a word. Some women must get stronger with age- lol.
GotM4, that is a sweeeet setup. If you want to try an uber lightweight light option, I'm interested in trying the new S&W Flashlights 3V weaponlight the
same way you have yours setup. Should be shorter and significantly lighter than the TL3 or X300.
My Google Fu is weak. What weapon light are you referring to?!
A few questions Regarding the JP LMOS unit
What is the difference in weight between the JP unit and a BCM carrier?
I saw the JP does not have forward assist cuts - no worries about using this with a upper with forward assist, no?
Is the JP unit considered good for just plinking or competition, or would you trust it as your carrier on your goto gun?
Thanks!
Awesome, inspiring project and setup. Based on this thread, I just grabbed a Streamlight TLR3 for my trunk gun mounted @ 12 o'clock.
Robb Jensen
02-13-10, 07:33
A few questions Regarding the JP LMOS unit
What is the difference in weight between the JP unit and a BCM carrier?
I saw the JP does not have forward assist cuts - no worries about using this with a upper with forward assist, no?
Is the JP unit considered good for just plinking or competition, or would you trust it as your carrier on your goto gun?
Thanks!
In my opinion forward assist isn't needed. If your bolt won't close under spring tension, you probably have a problem and should remedy it not force the bolt to close or you may cause yourself an even bigger problem.
On this rifle since the carrier didn't have forward assist notches I removed the forward assist from the gun and installed a delrin plug available from ADCO. The JP carrier is as durable as any other carrier (it's made of stainless steel and is IonBonded IIRC twice from speaking to JP). These lighter carriers actually require a little more gas to make them work correctly, on a midlength this isn't a problem. They sometimes will short stroke in ARs with rifle length gas systems and small gas ports. It's all part of the momentum equation (they run out of rearward momentum sooner). This was the whole reason why I shot a lot of Radway Green ammo through it to test for function. The Radway Green I have won't run some of my guns with CAR gas systems. This rifle eats it up.
JP LMOS carrier with key = 6.25oz.
M16 carrier with key = 9.47oz.
I like that lightweight upper. I'm planning to use that same Troy rail in my next installation. I've searched through the entire post but couldn't find any mentioning of the Troy handguard installation method, so here is my question.
Do you need any special proprietary tools to install the Troy rail? i.e. Troy specific barrel nut wrench, etc.
Thanks.
Do you need any special proprietary tools to install the Troy rail? i.e. Troy specific barrel nut wrench, etc.
My TRX-E came with the special barrel nut wrench and was GTG.
Robb Jensen
02-22-10, 21:31
I like that lightweight upper. I'm planning to use that same Troy rail in my next installation. I've searched through the entire post but couldn't find any mentioning of the Troy handguard installation method, so here is my question.
Do you need any special proprietary tools to install the Troy rail? i.e. Troy specific barrel nut wrench, etc.
Thanks.
I don't like the Troy wrench. What I do is really grease up the barrel nut with Brownells Action Lube Plus and use a DPMS or Smith Enterprise wrench and torque the stock Troy bbl nut up very slowly starting at 35ft lbs and adjusting the torque wrench adding 5ft lbs each time between loosening. This keeps me from bending the teeth on the nut.
I don't like the Troy wrench. What I do is really grease up the barrel nut with Brownells Action Lube Plus and use a DPMS or Smith Enterprise wrench and torque the stock Troy bbl nut up very slowly starting at 35ft lbs and adjusting the torque wrench adding 5ft lbs each time between loosening. This keeps me from bending the teeth on the nut.
Robb,
I may have missed it, but what is the max torque you end-up tightening the troy barrel nut down to?
Robb Jensen
02-23-10, 06:07
Robb,
I may have missed it, but what is the max torque you end-up tightening the troy barrel nut down to?
On most I'm finding alignment between 40-55lbs. Just go slow and steady.
The really early Troy barrels nuts were thin like USGI barrels nuts and the last 9-10 TRX/VTAC TRX rails I've installed had beefed up barrel nuts. The old ones were super easy to bend barrel nut teeth.
Al U. 5811
02-23-10, 10:32
gotM4,
Who, other than Sun Devil, makes a flat top upper w/o an FA? I'm not sure if Sun Devil has feed ramps in their non-FA upper.
LonghunterCO
02-23-10, 16:27
gotM4,
Who, other than Sun Devil, makes a flat top upper w/o an FA? I'm not sure if Sun Devil has feed ramps in their non-FA upper.
Assuming that you are looking for a light weight build I would stay from the milled upper like Sun Devil. I would look for a Rock River 9mm upper ( I think that ADCO has had them in stock yesterday).
TwoSqueeze
02-24-10, 12:31
gotM4,
Who, other than Sun Devil, makes a flat top upper w/o an FA? I'm not sure if Sun Devil has feed ramps in their non-FA upper.
I know that VLTOR makes a billet upper w/o FA. I think that Black Rain Ordenance does as well.
-TS
I would look for a Rock River 9mm upper ( I think that ADCO has had them in stock yesterday).
you're going to need a hole for that pesky gas tube. ;)
Al U. 5811
02-24-10, 20:52
I would think that a billit upper would defeat the purpose of light weight.
Robb Jensen
02-24-10, 20:52
I would think that a billit upper would defeat the purpose of light weight.
Yes they are 1oz heavier, sometimes more vs. a standard forged upper receiver.
...Components:
RRA 1x8 16" midlength barrel cut to 14.5" and turned down to .565" barrel profile...
What is the decimel inch profile for a pencil bbl? (i.e. .565")
I want to have my BCM 16" middy turned down by Adco and cut down for weight like your build. Would 14.5" or 14.7" be optimal for reliability?
Robb Jensen
02-24-10, 21:31
What is the decimel inch profile for a pencil bbl? (i.e. .565")
I want to have my BCM 16" middy turned down by Adco and cut down for weight like your build. Would 14.5" or 14.7" be optimal for reliability?
I'm not sure what BCM is using for a gas port, Project Featherweight is a RRA stainless 1x8 midlength 16" which was cut to 14.5", the gas port wasn't touched.
Most 'pencil barrels' are .625" (5/8"). Project Featherweight is .565" I believe .555" is about the lightest one should turn it to. The gas block seat was left at .750" so that a custom gas block wasn't needed.
-do the RRA 9m upper have a hole for the gas tube?
-can you take off the shell deflector deal thing on those 9mm uppers and allow for a full size ejection port?
-does someone else make a 556 picatinny upper sans forward assist?
Thoughts of a uber light upper, maybe put grooves in the bolt carrier like the scandinavian G-3 varients to allow a thumb/finger forward assist.
-do the RRA 9m upper have a hole for the gas tube? No, but ADCO offers the service to add it.
-can you take off the shell deflector deal thing on those 9mm uppers and allow for a full size ejection port? Yes.
very cool. thanks for your reply gotm4. just another project to start!
:D
LonghunterCO
02-25-10, 16:28
Yes the 9mm upper does need the gas tube drill and ADCO is the only one that I know that lists that as one of their shop services. The ejection port door can be replaced with a standard door. Several the the parts can be reused (the Rod (?) and retaining "C" and the port spring. Only the 3/4 door itself needs to be replaced wtih a full length door.
Perhaps I have missed a "chart of lightness" has anyone produced one of these yet?
Is a moe grip lighter than an A1?
The new mini Troy grip?
Are HK mp7 sights the lightest?
Weights of flashhiders?
The 9mm RRA upper vs standard?
I can see a middy using a light buffer and carrier... Maybe a new project aloft :)
Perhaps I have missed a "chart of lightness" has anyone produced one of these yet?
Yeah, chart of lightness would be awesome.
Chart of Lightness.....I was thinking about that yesterday as I've weighed numerous barrels, mags, lights, etc.
I have a similar setup to GotM4 and here's what it weighs.
CMMG 14.5" pencil barrel, midlength gas
Vltor low pro gas block
VTAC TRX 11" rail with only the top rail
BCM M4 upper
pinned Phantom FH
BCM F/A BCG
BCM Gunfighter CH
3 lbs, 8.9 ounces
without the BCG and CH it's 2 lbs 12 ounces
an AR lower with 2.9oz buffer and Vltor stock weighs 2 lbs 3.3 ounces
Robb Jensen
02-27-10, 21:55
Perhaps I have missed a "chart of lightness" has anyone produced one of these yet?
Is a moe grip lighter than an A1?
The new mini Troy grip?
Are HK mp7 sights the lightest?
Weights of flashhiders?
The 9mm RRA upper vs standard?
I can see a middy using a light buffer and carrier... Maybe a new project aloft :)
A1 and A2 are lighter than a MOE grip.
Haven't weighed a Troy grip nor the HK MP7 sights but the DDs are the lightest I have weighed. The FSC556 is the same weight as an A1 flash hider.
Haven't weighed a 9mm upper against a A4 upper with the forward assist removed.
tr1kstanc3
03-20-10, 21:06
gotm4-
Did you ever coat this rifle in Norrell's moly resin? I'd like to see its current configuration. I'm looking for somebody to do my lightweight BCM middy barrel in moly resin and was wondering if you are doing this work? Thanks.
Robb Jensen
03-20-10, 21:07
gotm4-
Did you ever coat this rifle in Norrell's moly resin? I'd like to see its current configuration. I'm looking for somebody to do my lightweight BCM middy barrel in moly resin and was wondering if you are doing this work? Thanks.
No it's probably going to get some Krylon. I'm not doing finishing work at this time.
tr1kstanc3
03-20-10, 21:12
No it's probably going to get some Krylon. I'm not doing finishing work at this time.
Okay thanks.
jasonhgross
03-23-10, 09:35
I am considering going with this same build up using the BCM lightweight upper. Any updates on how the JP bolt been for reliability ? Also, what buffer and spring are you using with it?
Robb Jensen
03-24-10, 21:53
I am considering going with this same build up using the BCM lightweight upper. Any updates on how the JP bolt been for reliability ? Also, what buffer and spring are you using with it?
I'm using a CAR buffer (3oz), so far 100% reliable, 1200 rounds fired, 600 rounds of that Radway Green 62gr (SS109 projectile).
I am building a lightweight for my wife:
1. CMMG govt profile 11.5"barrel
2. Clark custom carbon fiber handguard - 6oz
3. ACE ultra light stock
4. Looking for a no F/A upper receiver
Robb Jensen
03-24-10, 22:23
Perhaps I have missed a "chart of lightness" has anyone produced one of these yet?
Is a moe grip lighter than an A1?
The new mini Troy grip?
Are HK mp7 sights the lightest?
Weights of flashhiders?
The 9mm RRA upper vs standard?
I can see a middy using a light buffer and carrier... Maybe a new project aloft :)
I'm not good at making Charts maybe Rob_S will make one. I'm more than willing to help supply the data as I have a lot of access to a lot of stuff to weigh.
there used to be a Maryland AR shooters MSN group that had a huge spreadsheet of weights of just about everything. I think the group went away and therefore who knows what happened to the chart. I think I saved it a couple of times so if I can find it I'll put it in google docs, share it, and we can start adding to it. Might take me a little bit to find.
there used to be a Maryland AR shooters MSN group that had a huge spreadsheet of weights of just about everything. I think the group went away and therefore who knows what happened to the chart. I think I saved it a couple of times so if I can find it I'll put it in google docs, share it, and we can start adding to it. Might take me a little bit to find.
I found a few two year old archived versions of the Maryland AR Shooters (once excellent) site.
http://web.archive.org/web/20080524203951rn_1/groups.msn.com/TheMarylandAR15ShootersSite/_homepage.msnw?pgmarket=en-us
http://tinyurl.com/ybhrepk
Both take a long, long time to load and navigate. The second appears to be slightly faster, but the colors make reading menus a PIA. If I can find the chart there, I'll post it.
ETA: I'm thinking of dedicating a computer to just navigating this stuff. I've yet to get beyond the first page. But, one poster on another site (not TOS) stated they got some info off the archive a few weeks ago, so ...)
Bad news: the link to that chart is DEAD. The reference notes that it was member-only accessible, and that may explain it.
rob_s: no pressure. ;)
Robb Jensen
03-25-10, 13:33
Bad news: the link to that chart is DEAD. The reference notes that it was member-only accessible, and that may explain it.
rob_s: no pressure. ;)
I weighed a bunch of stuff today. I'll get it posted up tonight and then Rob_S can use it in a parts weight chart.
I weighed a bunch of stuff today. I'll get it posted up tonight and then Rob_S can use it in a parts weight chart.
Once I find, and convert, the Maryland chart I'll start a new thread where we can compile info into one place.
Wold be good to get people to post pictures of the items on the scale as it alleviates any confusion (was that with the screws or without, what xyz did you have inserted, etc.).
Bad news: the link to that chart is DEAD. The reference notes that it was member-only accessible, and that may explain it.
rob_s: no pressure. ;)
I was a member, which is how I got the chart the first time, but I think the group is defunct.
Robb Jensen
03-27-10, 22:04
Here's what I have so far. I just don't have enough time in the day to take pics of everything on the scale.
Colt CAR stock body (plastic) 4.4oz
VLTOR E-Mod stock 13.6oz
LMT SOPMOD stock body 11.3oz
Magpul CTR stock body 8.9oz
Magpul UBR body 1lb 7.3oz
Magpul PRS body 1lb 10.9oz
Rifle receiver extension 3.4oz
Magpul UBR aka entry length receiver extension 2.7oz
Unknown mil-spec carbine receiver extension 3.8oz
VLTOR mil-spec receiver extension 3.7oz
BCM castle nut and end plate 1.2oz
Daniel Defense QD end plate (w/o QD loop) 0.4oz
Commercial A2 pistol grip 2.6oz
Magpul MOE pistol grip 2.4oz
Tangodown pistol grip 3.6oz
Hogue pistol grip 2.7oz
Ergo pistol grip 3.2oz
Aluminum OEM triggerguard 0.3oz
Magpul MOE triggerguard 0.2oz
Magpul enhanced triggerguard 0.5oz
Norgon ambi-catch (no stock spring or button) 0.5oz
OEM mag catch (no spring or button) 0.4oz
Troy flip up rear sight 1.8oz
Troy fixed rear sight 2.1oz
DD fixed rear sight 1.7oz
DD fixed front sight 1.2oz
Magpul MBUS front sight 1.2oz
LMT MRP fixed front sight 2.2oz
A2 flash hider 2.1oz
A1 flash hider 2.0oz
Surefire Brake (for 556K, 212) 3.8oz
Troy medieval flash hider 3.0oz
Magpul 20 round magazine (w/o dust cover) 3.4oz
Lancer 30 round magazine 4.2oz
Tangodown 30 round magazine 5.3oz
VTAC low profile QD sling mount 0.8oz
VTAC LUSA sling mount 0.9oz
BCM standard CH 1.2oz
BCM bolt 1.6oz
BCM cam pin 0.3oz
BCM carrier key and screws 0.9oz
BCM Forward assist and spring 0.9oz
A2 delta ring assy 2.7oz
Snap ring 0.2oz
Weld spring 0.3oz.
Delta ring A2 0.9oz
Barrel nut (stock) 1.3oz
A1 handguard ring (ring only) 0.4oz
CAR/M4 handguard cap 0.4oz
Arrendondo mag catch (plastic button, 2 screws and button extension) 0.2oz
OEM mag catch button 0.1oz
Magpul AFG with screw and flat insert 3.0oz
VTAC light mount 1.8oz
Dust door assy, spring, rod and c-clip 0.8oz
BCM firing pin 0.3oz
Magpul ASAP 1.4oz
Gear Sector end plate 0.7oz
BCM long A2 flash hider 2.3oz
RRA 2 stage trigger with springs and pins 2.5oz
Geissele SSA trigger with springs and pins 2.3oz
OEM fire control (hammer, trigger, disconnector, pins and springs) 2.5oz
AAC M4-2000 51 tooth brake 3.7oz
Magpul enhanced (long) stock pad (w/o screws) 2.1oz
Troy 9 TRX rail with bbl nut and two mounting screws 8.7oz
VTAC/Troy TRX 9 rail with bbl nut and two mounting screws 9.8oz
VTAC/Troy TRX 11 rail with bbl nut and two mounting screws 11.4oz
VTAC/Troy TRX 13 rail with bbl nut and two mounting screws 12.6oz
DD 12 RIS II rail with all mounting screws, bbl nut, 6 screws and flange 1lb 2.2oz
DD 12 RIS II FSB model with all mounting screws, bbl nut, 6 screws and flange 1lb 12oz
DD 9.5 RIS II Mk18 rail with all mounting screws, bbl nut, 6 screws and flange 14.3oz
DD 10 Lite rail with all mounting screws, bbl nut, 6 screws and flange 13.0oz
DD 9 Lite rail with all mounting screws, bbl nut, 6 screws and flange 12.2oz
DD 12 Omega with all mounting hardware 13.6oz
DD 9 Omega with all mounting hardware 9.9oz
DD 7 Omega with all mounting hardware 7.8oz
DD 7 Omega piston rail with all mounting hardware 8.4oz
YHM 12 diamond rail barrel nut, slip ring and 2 anti-rotational screws 1lb 4.3oz
YHM Spectre length diamond rail with barrel nut, slip ring and 2 anti-rotational screws 1lb 0.5oz
Okay, Robb, so tell us the stock number at VA Arms so we can order one?
I consider this a serious question.
:D
Here's what I have so far. I just don't have enough time in the day to take pics of everything on the scale.
Colt CAR stock body (plastic) 4.4oz
VLTOR E-Mod stock 13.6oz
LMT SOPMOD stock body 11.3oz
Magpul CTR stock body 8.9oz
Magpul UBR body 1lb 7.3oz
Magpul PRS body 1lb 10.9oz
Rifle receiver extension 3.4oz
Magpul UBR aka entry length receiver extension 2.7oz
Unknown mil-spec carbine receiver extension 3.8oz
VLTOR mil-spec receiver extension 3.7oz
BCM castle nut and end plate 1.2oz
Daniel Defense QD end plate (w/o QD loop) 0.4oz
Commercial A2 pistol grip 2.6oz
Magpul MOE pistol grip 2.4oz
Tangodown pistol grip 3.6oz
Hogue pistol grip 2.7oz
Ergo pistol grip 3.2oz
Aluminum OEM triggerguard 0.3oz
Magpul MOE triggerguard 0.2oz
Magpul enhanced triggerguard 0.5oz
Norgon ambi-catch (no stock spring or button) 0.5oz
OEM mag catch (no spring or button) 0.4oz
Troy flip up rear sight 1.8oz
Troy fixed rear sight 2.1oz
DD fixed rear sight 1.7oz
DD fixed front sight 1.2oz
Magpul MBUS front sight 1.2oz
LMT MRP fixed front sight 2.2oz
A2 flash hider 2.1oz
A1 flash hider 2.0oz
Surefire Brake (for 556K, 212) 3.8oz
Troy medieval flash hider 3.0oz
Magpul 20 round magazine (w/o dust cover) 3.4oz
Lancer 30 round magazine 4.2oz
Tangodown 30 round magazine 5.3oz
VTAC low profile QD sling mount 0.8oz
VTAC LUSA sling mount 0.9oz
BCM standard CH 1.2oz
BCM bolt 1.6oz
BCM cam pin 0.3oz
BCM carrier key and screws 0.9oz
BCM Forward assist and spring 0.9oz
A2 delta ring assy 2.7oz
Snap ring 0.2oz
Weld spring 0.3oz.
Delta ring A2 0.9oz
Barrel nut (stock) 1.3oz
A1 handguard ring (ring only) 0.4oz
CAR/M4 handguard cap 0.4oz
Arrendondo mag catch (plastic button, 2 screws and button extension) 0.2oz
OEM mag catch button 0.1oz
Magpul AFG with screw and flat insert 3.0oz
VTAC light mount 1.8oz
Dust door assy, spring, rod and c-clip 0.8oz
BCM firing pin 0.3oz
Magpul ASAP 1.4oz
Gear Sector end plate 0.7oz
BCM long A2 flash hider 2.3oz
RRA 2 stage trigger with springs and pins 2.5oz
Geissele SSA trigger with springs and pins 2.3oz
OEM fire control (hammer, trigger, disconnector, pins and springs) 2.5oz
AAC M4-2000 51 tooth brake 3.7oz
Magpul enhanced (long) stock pad (w/o screws) 2.1oz
Troy 9 TRX rail with bbl nut and two mounting screws 8.7oz
VTAC/Troy TRX 9 rail with bbl nut and two mounting screws 9.8oz
VTAC/Troy TRX 11 rail with bbl nut and two mounting screws 11.4oz
VTAC/Troy TRX 13 rail with bbl nut and two mounting screws 12.6oz
DD 12 RIS II rail with all mounting screws, bbl nut, 6 screws and flange 1lb 2.2oz
DD 12 RIS II FSB model with all mounting screws, bbl nut, 6 screws and flange 1lb 12oz
DD 9.5 RIS II Mk18 rail with all mounting screws, bbl nut, 6 screws and flange 14.3oz
DD 10 Lite rail with all mounting screws, bbl nut, 6 screws and flange 13.0oz
DD 9 Lite rail with all mounting screws, bbl nut, 6 screws and flange 12.2oz
DD 12 Omega with all mounting hardware 13.6oz
DD 9 Omega with all mounting hardware 9.9oz
DD 7 Omega with all mounting hardware 7.8oz
DD 7 Omega piston rail with all mounting hardware 8.4oz
YHM 12 diamond rail barrel nut, slip ring and 2 anti-rotational screws 1lb 4.3oz
YHM Spectre length diamond rail with barrel nut, slip ring and 2 anti-rotational screws 1lb 0.5oz
Tryin' to make me get off my ass and find that chart, aren't you. :D
I know I have it, it's just a matter of which of three external hard drives (none of which are currently connected to anything) that I have to go through.
Robb Jensen
03-28-10, 21:15
Tryin' to make me get off my ass and find that chart, aren't you. :D
I know I have it, it's just a matter of which of three external hard drives (none of which are currently connected to anything) that I have to go through.
You can do it! :D
Troy 9 TRX rail with bbl nut and two mounting screws 8.7oz
VTAC/Troy TRX 9 rail with bbl nut and two mounting screws 9.8oz
VTAC/Troy TRX 11 rail with bbl nut and two mounting screws 11.4oz
VTAC/Troy TRX 13 rail with bbl nut and two mounting screws 12.6oz
Does the 11" Troy TRX Extreme on your featherweight weigh about the same as the VTAC?
ForTehNguyen
03-29-10, 09:23
we need to sticky that type of parts weight list. I have a postal scale coming in so I can add more to the list as well.
Robb Jensen
03-29-10, 14:55
Does the 11" Troy TRX Extreme on your featherweight weigh about the same as the VTAC?
Judging from the 9" weights where the 9" VTAC/Troy is heavier by about an ounce. I'm sure the 11" VTAC/Troy is heavier than the Troy TRX as well.
Judging from the 9" weights where the 9" VTAC/Troy is heavier by about an ounce. I'm sure the 11" VTAC/Troy is heavier than the Troy TRX as well.you're right, missed that.
ForTehNguyen
03-30-10, 22:43
My postal scale came in today, here are some more AR15 component weights:
Lowers are assumed to have LPKs
Uppers are weighed without BCG, CH, handguards, front/rear sights unless otherwise stated
Uppers are assumed to have front sight tower if no front sight is stated. All uppers have A2 FHs
BCM 16" Midlength Lighweight Upper: 2lb 11.2oz
BCM 16" Midlength + DD Lite 12.0 + Eotech 512 + Magpul MBUS Front/Rear + 3x Rail Ladders: 4lb 6.6oz
20" BCM Govt Profile Upper + Carry Handle: 3lb 13.4oz
Delton 16" Midlength HBAR + Magpul MBUS Rear: 3lb 8.9oz
Cav-15 MkII Lower + CAR Buffer/Spring: 1lb 11.6oz
Lower + A2 Stock + Rifle Buffer/Spring: 2lb 8.1oz
Lower + H Buffer/Spring + Magpul MIAD + ACS + BAD + ASAP: 2lb 11.1oz
Lower + CAR Buffer/Spring + Magpul UBR + BAD + MOE Grip: 2lb 14.4oz
Rifle Handguards: 9.6oz
BCM M16 BCG: 11.5oz
Delton Semi BCG: 11.1oz
Charging Handle: 1.1oz
BCM Gunfighter CH Mod3: 1.3oz
BCM Gunfighter CH Mod4: 1.2oz
Delton Midlength Handguards: 6.9oz
Magpul Rail Ladder: .4oz
Magpul AFG: 2.9oz
Magpul BAD: .2oz
Magpul MBUS Rear: 1.4oz
Magpul MS2 Sling: 7.9oz
Cav-15 MkII Sling: 2.6oz
QD Swivel: .9oz
Bobro Stubby VFG: 3.8oz
Prvi Partizan 5.56mm M193: 11.9gr = .420oz
Centurion .223 55gr: 11.4g = .402oz
Magpul PMAG RevM + 30x Prvi Partizan 55gr M193 + Mag cover: 1lb 1.8oz
Magpul PMAG RevM + 30x Centurion .223 55gr + Mag cover: 1lb 1.2oz
Magpul PMAG Old + 30x Centurion .223 55gr + Mag cover: 1lb 1.7oz
Magpul PMAG 20 + 20x Prvi Partizan 55gr M193 + Mag cover: 12.1oz
CProducts USGI Mag + Magpul Follower: 4.1oz
Troy 9 TRX rail with bbl nut and two mounting screws 8.7oz
VTAC/Troy TRX 9 rail with bbl nut and two mounting screws 9.8oz
VTAC/Troy TRX 11 rail with bbl nut and two mounting screws 11.4oz
VTAC/Troy TRX 13 rail with bbl nut and two mounting screws 12.6oz
Troy says the 11" TRX extreme weighs 9.93 with rail sections. Maybe that's without the bbl nut though?
New Viking Tactics VTAC EXTREME BattleRail - By Troy Industries (https://www.m4carbine.net/showpost.php?p=454800&postcount=25)
sniperfrog
04-02-10, 14:43
Anybody try using one of those Clark carbon fiber float tubes? I think there only like 6 ounces. Durability might be an issue though.
Robb Jensen
04-02-10, 17:24
Anybody try using one of those Clark carbon fiber float tubes? I think there only like 6 ounces. Durability might be an issue though.
Those are insanely light but what I hated about them is that the tube had to be glued to the bbl nut. If you had one covering a low pro gas block it'll be a bitch to remove the tube to change a gas tube.
LonghunterCO
04-02-10, 17:44
Those are insanely light but what I hated about them is that the tube had to be glued to the bbl nut. If you had one covering a low pro gas block it'll be a bitch to remove the tube to change a gas tube.
I have a hiperform litewieght CF FF handguard tube (they are supposed to lighter than the Clarks) but I am running it on a fixed front sight upper. I would be tempted to run the upper with the GB just a head of the end of the handguard if I had to glue it up.
The Dumb Gun Collector
04-02-10, 18:21
Inspired by your post, I finally pulled the trigger on a DD lite 16 inch barrel and 6 inch DD light rail with Grant. Hopefully I will have it by next weekend. I was at a Hackathorn class this weekend and Sam from this forum had his. It was quite nice. I sold off my trusty Colt Tactical upper. It was a great upper but it is time for me to jump on the lightweight bandwagon.
Greg:
You should have gotten the Troy Extreme rail like mine. I really like the 11" tube, you can mount the rear sight back from the front and put a light at 12 o'clock for ambidextrous use.
The Dumb Gun Collector
04-02-10, 19:53
I wanted to keep a fixed front sight and I wanted a rail with a profile more like the one on my 416. Plus, I am not really sold on the 12 o'clock mount....yet.
.... Plus, I am not really sold on the 12 o'clock mount....yet.
Stubborn man.:D
The Dumb Gun Collector
04-02-10, 20:47
Lol. I just went through my third carbine class in as many years with a hbar 1/9 with a surefire m500. Stubborn is the nice way of putting it.
My Troy TRX Extreme BattleRail 7.6in came in yesterday so today I took it to the Post Office. It has a scale in the lobby that is accessible when its closed.
Rail without barrel nut 6.0oz.
Rail with barrel nut 7.5oz
Two inch rail with screws and backing - .9oz
Four inch rail with screws and backing 1.6oz
Thank you for posting the weight list.
Thank you for posting the weight list.
+1......this will come in handy.
FMJs-of-Freedom
04-08-10, 10:27
I would reprofile the barrel to a lighter weight and that it. FMJs-of-Freedom
Found the chart, posted new thread
http://m4carbine.net/showthread.php?p=630961#post630961
http://sphotos.ak.fbcdn.net/hphotos-ak-ash1/hs489.ash1/26754_388949908698_595683698_3712097_514499_n.jpg
Polymer lower, Carbon fiber forearm, 11.5" cmmg Govt. Profile barrel.
http://hphotos-snc3.fbcdn.net/hs489.snc3/26754_388374348698_595683698_3698310_2632439_n.jpg
ForTehNguyen
04-28-10, 08:09
my BCM 16" middy lightweight with Cav Arms lower was about 5lbs 12oz, center of balance somewhere above the magwell
Robb Jensen
05-02-10, 13:00
http://sphotos.ak.fbcdn.net/hphotos-ak-ash1/hs489.ash1/26754_388949908698_595683698_3712097_514499_n.jpg
Polymer lower, Carbon fiber forearm, 11.5" cmmg Govt. Profile barrel.
http://hphotos-snc3.fbcdn.net/hs489.snc3/26754_388374348698_595683698_3698310_2632439_n.jpg
Very nice but it is a SBR.
Nothing wrong with that but my wifes rifle Project Featherweight was to be a non-SBR so that additional paperwork to take it out of state on vacation or emergencies wasn't necessary. Had it been an SBR I would have make it a 11.5" CAR gas barrel turned to .555-.565" with a Troy TRX 9" rail which would have saved more weight. If CAV arms made a lower with an 'entry' or Sully length stock I'd use that too. That would be damn lightweight.
LonghunterCO
05-02-10, 13:13
If CAV arms made a lower with an 'entry' or Sully length stock I'd use that too. That would be damn lightweight.
There is a guy over at TOS that cuts the Cav stock/receivers down (he's from TX) replaces the butt pad with a rubber one. He says that there is a couple oz reduction in weight.
http://sphotos.ak.fbcdn.net/hphotos-ak-ash1/hs489.ash1/26754_388949908698_595683698_3712097_514499_n.jpg
Polymer lower, Carbon fiber forearm, 11.5" cmmg Govt. Profile barrel.
http://hphotos-snc3.fbcdn.net/hs489.snc3/26754_388374348698_595683698_3698310_2632439_n.jpg
Sorry but I cant stand that lower. At least use a bushmaster carbon upper/lower combo....
Robb Jensen
05-02-10, 13:33
There is a guy over at TOS that cuts the Cav stock/receivers down (he's from TX) replaces the butt pad with a rubber one. He says that there is a couple oz reduction in weight.
You have my ear! Please PM his contact info.
Stonerriflefan44
05-03-10, 10:18
Anyone know what the weight savings are between a LW barrel vs a standard M4 profile barrel? Any pros or cons to having an exsisting barrel re-profiled?
ForTehNguyen
05-03-10, 12:09
Anyone know what the weight savings are between a LW barrel vs a standard M4 profile barrel? Any pros or cons to having an exsisting barrel re-profiled?
Daniel Defense posted a while back saying theirs a 6oz difference b/t their govt carbine uppers vs the pencil carbine uppers. Keep in mind this is 6oz off the end of the barrel, so it feels like it loses more weight than that and shifts the center of balance of the rifle more towards you.
Reprofiling it is another way to do this also. I cant think of any cons
There are many members on M4C with much more knowledge than I, but what I've gleaned from this forum and various vendors is about 5-6 oz weight savings from a 16" BBL.
Yes, you can re-profile/re-contoured the barrel too. Those who have had this done by Adco have very favorable reviews. The only downside is the cost at $95 + shipping to and from Adco. Not a big expense if you already have a barrel, but perhaps not the best choice if you're considering the purchase of a new M4 barrel and the re-profiling.
Mike Miller
05-05-10, 08:35
You could also take it to a machine shop for profiling. I had my WOA 18" turned down by a local shop in Gainesville for $40.
another wat to shave a few ounces would be a slickside upper- adco will drill a hole for a gas tube in a 9mm upper- no forward assist housing or brass deflector
There is a guy over at TOS that cuts the Cav stock/receivers down (he's from TX) replaces the butt pad with a rubber one. He says that there is a couple oz reduction in weight.You have my ear! Please PM his contact info.
I am interested as well because I would like a shorter LOP on my CAV Arms lower, can you PM me the info as well? Also for the uninitiated what is TOS?
Thanks!
DFW guns in Dallas, I have one of his receivers.
TOS: the other site, Ar15.com
Tornado_Racing
05-27-10, 08:16
This is a carbine I built up for my wife. The goal was to make an extremely lightweight non-SBR. This wasn't meant to be a heavy use gun high round count gun but rather one that would always be near while traveling and that which is easily handled. It weighs 87ozs, aka 5.43lbs. I'm going to coat the barrel, both receivers, receiver extension and Troy tube in Norrels FDE and then Krylon everything. I may replace the front sight with a DD fixed front and use a Surefire X300 in front of it.
Components:
RRA 1x8 16" midlength barrel cut to 14.5" and turned down to .565" barrel profile, chamber reamed from .223 Wylde to 5.56 mm NATO, FSB shaved and then cut in half only using the rear half, PWS FSC556 pinned/welded for 16-1/16th" overall barrel length.
CMT upper receiver with no dust door or forward assist. I'm using a delrin plug from ADCO to plug the upper receivers hole for the forward assist. JP LMOS carrier (no forward assist cuts) with BCM bolt, cam pin and firing pin. BCM standard charging handle. Double Star lower with Stag lower parts kit. Colt grip and Colt CAR stock. VLTOR receiver extension, BCM castle nut and end plate, CMT CAR buffer and spring. Magpul MOE triggerguard and MBUS sights. Aimpoint H1 in a Daniel Defense Micro mount.
http://img.photobucket.com/albums/v408/gotm4/gunpics/projectfeatherweight2.jpg
http://img.photobucket.com/albums/v408/gotm4/gunpics/projectfeatherweight3.jpg
Hey Robb,
Do you have any pics of this? PM inbound as well.
Tony
http://i282.photobucket.com/albums/kk253/9DivDoc/IMG_0001-2.jpg
Wife's 16" Bushmaster Super Lt.Wt. barrel
Larue .625 gas block
PRI middie tube with light wt Al barrel nut
VLTOR FDE Imod stock
Sherman A. House
05-29-10, 22:39
You have my ear! Please PM his contact info.
Hey Rob,
Jim Fuller at Rifle Dynamics ( www.rifledynamics.com ) cuts them down too, and in fact carries them in stock, in a variety of lengths.
Robb Jensen
05-29-10, 23:00
Hey Rob,
Jim Fuller at Rifle Dynamics ( www.rifledynamics.com ) cuts them down too, and in fact carries them in stock, in a variety of lengths.
Thanks I'll look into that, she shoot an old CAR stock like that 1 click out.
What about a Les Baer upper with no forward assist at all?
Mine finally arrived. 1.1 oz. less than a standard M4 upper with FA. Leaving off the dustcover and associated parts would save another 0.7 oz.
Mine finally arrived. 1.1 oz. less than a standard M4 upper with FA. Leaving off the dustcover and associated parts would save another 0.7 oz.
Haven't received mine yet. Is the 1.1 oz weight savings based on the weight of stripped LB/no fwd assist provision upper vs. that of a complete M4 upper?
Just curious since I weighted a stripped Daniel Defense upper and it was only 202 g or 7.1 oz.
Edit: Rob_s, thanks for the PM.
I wasn't sure if I should post in the parts chart thread or this one, but since it meets the featherweight criterion, I'll place it here.
This arrived today and will be going on my Robb-inspired lightweight. Micor Industries titanium flash suppressor, optimized for 1:7 twist barrels. I believe 1:8 through 1:10 are available.
http://i304.photobucket.com/albums/nn176/Dr_Wolfenstein/ARs/MicorTitaniumFHsm.jpg
It's actually 37.5 grams or a tick under 1 1/4 oz :eek: I haven't installed or tested it yet.
A pic of my Cav Arms lower, no scale to weigh it on right now
http://img541.imageshack.us/img541/83/image1xk.jpg
Chris
ForTehNguyen
06-03-10, 13:44
A pic of my Cav Arms lower, no scale to weigh it on right now
Chris
from post 107 in this thread, when I weighed the Cav Arms lower (LPK installed):
Cav-15 MkII Lower + CAR Buffer/Spring: 1lb 11.6oz
So maybe an ounce or so lighter since you cut the stock.
I wasn't sure if I should post in the parts chart thread or this one, but since it meets the featherweight criterion, I'll place it here.
This arrived today and will be going on my Robb-inspired lightweight. Micor Industries titanium flash suppressor, optimized for 1:7 twist barrels. I believe 1:8 through 1:10 are available.
It's actually 37.5 grams or a tick under 1 1/4 oz :eek: I haven't installed or tested it yet.
Are you putting it on a 14.5" or a 16"? I'm wondering if these will be long enough for a 14.5 perm attachment. Crush washer with silver solder seems like it would be very close..
I plan on using this on a 16".
The Micor suppressor is exactly 2" long and will add 1.5" to the overall length, so you'll be right at 16" with it.
Mine finally arrived. 1.1 oz. less than a standard M4 upper with FA. Leaving off the dustcover and associated parts would save another 0.7 oz.
Pics?
gotm4 it was nice meeting you today at topton.
Here's my lightweight.
6lb 6.6oz as shown
http://img.photobucket.com/albums/v629/njm1a/USANA%20Range/DSC_0175.jpg
http://img.photobucket.com/albums/v629/njm1a/USANA%20Range/DSC_0170.jpg
http://img.photobucket.com/albums/v629/njm1a/USANA%20Range/DSC_0156.jpg
Above is a cut down cav arms.
http://img.photobucket.com/albums/v629/njm1a/IMG_0262.jpg
This is compared to a sully stock.
QD Socket put in...
http://img.photobucket.com/albums/v629/njm1a/IMG_0244.jpg
Here is a video of the 4lb 13oz featherweight that I built being used at the range:
PlumCrazy polymer lower w/ 11.5" CMMG barrel (http://www.youtube.com/watch?v=QUVhd62mPAI)
Above is a cut down cav arms.
http://img.photobucket.com/albums/v629/njm1a/IMG_0262.jpg
This is compared to a sully stock.
QD Socket put in...
http://img.photobucket.com/albums/v629/njm1a/IMG_0244.jpg
Does that cut down Cav Arms have a rifle or carbine tube?
LonghunterCO
07-30-10, 10:21
Cav arms has a built in buffer tube/receiver extention. It uses a carbine spring and buffer.
Robb Jensen
08-14-10, 11:31
Latest pics of Project Featherweight with Krylon:
http://img.photobucket.com/albums/v408/gotm4/BravoCoUSA%20and%20BCM%20album/ProjectFeatherweight3.jpg
http://img.photobucket.com/albums/v408/gotm4/BravoCoUSA%20and%20BCM%20album/ProjectFeatherweight.jpg
http://img.photobucket.com/albums/v408/gotm4/BravoCoUSA%20and%20BCM%20album/ProjectFeatherweight2.jpg
Latest pics of Project Featherweight with Krylon:
http://img.photobucket.com/albums/v408/gotm4/BravoCoUSA%20and%20BCM%20album/ProjectFeatherweight3.jpg
Looks nice. What's the total weight as shown?
GermanSynergy
08-14-10, 23:10
Robb- that is sweet! Awesome work!
Some great data in here.
I was wondering if anyone has compared the weights of various rail covers? I imagine the various ladder covers (I think they're all made by Ergo at the end of the day) are lightest - one of the posts in this thread have them at .4oz. Just curious if anyone has put the XTMs or KAC rail panels, for example, on the scale. Unfortunately my digital scale isn't precise enough for fractions of an ounce.
Of course, one of the nice things about using the Troy/VTAC Extreme handguards is that you don't need rail panels...
Rob,
is the front sight usable with that tlr3 @ 12 o'clock?
Robb Jensen
08-15-10, 22:16
Rob,
is the front sight usable with that tlr3 @ 12 o'clock?
It is usable but the light does cover 1/2 of the front sight post.
Some great data in here.
I was wondering if anyone has compared the weights of various rail covers? I imagine the various ladder covers (I think they're all made by Ergo at the end of the day) are lightest - one of the posts in this thread have them at .4oz. Just curious if anyone has put the XTMs or KAC rail panels, for example, on the scale. Unfortunately my digital scale isn't precise enough for fractions of an ounce.
Of course, one of the nice things about using the Troy/VTAC Extreme handguards is that you don't need rail panels...
I'm posting from my phone and can't get to the link but I did start to compile this information and break it down into a per-slot weight. I'll try to post when I get in front of a computer again.
Very nice rifles in here! I've been trying to put mine on a diet by adding as many polymer pieces in place of steel/aluminum. It used to weigh in at 8lbs, and it just felt like a pig sometimes. Hopefully I can shave off a pound or so and get it back into fighting weight.
Some great data in here.
I was wondering if anyone has compared the weights of various rail covers? I imagine the various ladder covers (I think they're all made by Ergo at the end of the day) are lightest - one of the posts in this thread have them at .4oz. Just curious if anyone has put the XTMs or KAC rail panels, for example, on the scale. Unfortunately my digital scale isn't precise enough for fractions of an ounce.
Of course, one of the nice things about using the Troy/VTAC Extreme handguards is that you don't need rail panels...
Tango Down 6" SCAR Panel - .9 oz
1 pack XTM panels - .9 oz
Rmplstlskn
09-16-10, 17:32
Did you spend a lot of time de-oiling and degreasing before painting? What cleaner did you use?
Curious how long the Krylon holds up... I'm sure the grips, levers and rail are the first to wear off...
Rmpl
Latest pics of Project Featherweight with Krylon:
http://sphotos.ak.fbcdn.net/hphotos-ak-ash1/hs489.ash1/26754_388949908698_595683698_3712097_514499_n.jpg
Polymer lower, Carbon fiber forearm, 11.5" cmmg Govt. Profile barrel.
http://hphotos-snc3.fbcdn.net/hs489.snc3/26754_388374348698_595683698_3698310_2632439_n.jpg
That is really light! What kind of accuracy do you get?
http://img.photobucket.com/albums/v408/gotm4/BravoCoUSA%20and%20BCM%20album/ProjectFeatherweight.jpg
http://img.photobucket.com/albums/v408/gotm4/BravoCoUSA%20and%20BCM%20album/ProjectFeatherweight2.jpg
What flash hider is that?
Verrrry nice gun.
Is the stock going to stay as is?
Robb Jensen
09-17-10, 13:33
What flash hider is that?
Verrrry nice gun.
Is the stock going to stay as is?
It's a PWS FSC556 pinned and welded to the 14.5" barrel. Yes the project is done and the rifle is staying in that configuration.
ForTehNguyen
10-08-10, 09:31
I modified my cav arms build using a spikes LW carbine upper, expecting to cut the weight slightly. I found out that it actually weighs 1oz more than the BCM LW midlength upper .750" gas block I had before (moved to a different rifle now). I noticed the taper is different on the chamber end of the barrel as compared to the middy. I went on BCMs website and saw that BCM did the same thing.
My conclusion is that middy vs carbine upper, there isnt a as weight loss as I'd expect with the carbine. I had assumed that since their is 2" more of barrel milled in front of the FST it would be lighter. I didnt consider the construction differences from under the handguard because I assumed it was the same. I wonder how much less weight a .750" block upper is vs an upper with .625" block. Obviously a middy handguard will weigh more than a carbine handguard by a couple oz so that has to be considered. But for anyone trying to make a LW build and deciding between a middy or carbine. I havent notice any significant difference. The carbine can possibly weigh just as much or more.
Notice how there is more metal near the delta ring on the carbine. Any idea why the carbine has it but the middy doesnt?
http://www.bravocompanyusa.com/v/vspfiles/photos/BCM-URG-MID-16LW-2.jpg
http://www.bravocompanyusa.com/v/vspfiles/photos/BCM-URG-Car-16LW-2.jpg
I'd be willing to think that the carbine upper doesn't have the same barrel profile as the middy does. It appears that the carbine actually has a thicker barrel profile overall. Looking at the FSB on the middy it steps down and appears thinner prior to and post of the FSB. The carbine barrel appears to be around .730 before and after the FSB so that probably makes for the visual difference as well.
Interesting. When my DD lightweight 14.5" barrel returns from ADCO I will have to try and get a comparable photo of the profile. I have a BCM lightweight 16" mid I can include in the photo for comparison purposes.
In the meantime here's the photo of 16" lightweight carbine-lengths from DD's website (http://www.danieldefense.com/?page=shop/detail&product_id=250) and the 16" lightweight mid-lenghths. Based on this the chamber-area profile appears to match the BCM mid-length.
carbine-length
http://www.danieldefense.com/img/product/f2ca80910c01e3c9db7d3037e4cf31fd.jpg
mid-length
http://www.danieldefense.com/img/product/a47b37e194eaba723bf5ab90f1bc230b.jpg
ForTehNguyen
10-08-10, 11:51
as of now I dont see much appreciable difference b/t the two gas systems on a LW profile, maybe 1-2oz at the most. Then you have to consider the handguard which can be another 2oz heavier on the middy. Carbine might have to use a heavier buffer so it can even it out slightly. I think its just going to be more user preference (middy advantages over carby vs 1-2oz of savings) to decide on which LW gas system. In theory I always thought the carby would be noticeably lighter, its not looking like that now. Right now I dont see why not the carbine can be milled to the same profile as a LW middy, but maybe theres a good reason. I just cant think of one.'
I changed my Cav Arms build to be iron sights only to cut down on the weight, its weighing about 5lbs 12.7oz, I think with the BCM upper it was a little under 5lbs 12oz. I had a Delton HBAR upper that I plan to sell so thats why I was moving the LW middy to make a KISS build. That HBAR is beefy compared to the BCM LW.
LonghunterCO
10-08-10, 12:04
Great info guys.
If keeping the FSB then you're exactly right that handguard length will affect overall weight. Obviously if going with a low-profile gas block it will be a little different. I wanted my gas-block covered but with as short a handguard as possible so I would have wound up with a heavier gun if I had gone mid-length.
In some ways I wish I had picked a mid-length 14.5" for my lightweight project but I'm sure the carbine will be sufficient. I don't really get too far down the path of buffer weights and would likely run an H in either gun provided the rifle functioned with it.
Inspiring thread... and great info. Thanks. :)
http://img32.imageshack.us/img32/3540/bgar.jpg
the clark custom handguards are a good bit less than 6 oz if you cut 2/3rds of it off :)
btw, 17" barrel and titanium comp
that stock is a BRICK though. it balances perfectly, and runs great using a classic magwell grip. I used to have a micro T1 on it, but it got moved to another gun.
I went a somewhat similar route; BCM 14.5" LW middy (actually a BCM 16" LW that was chopped by JoJo's). Still early in the process of range work, but so far I'm pretty happy with it. Just got the IWC QD point in the mail today which is the only thing missing in the pictures below. If all goes well after this weekend, it'll get sprayed.
Light weight was the theme, but not the overriding decision for each piece of equipment. I had been waiting on BCM to introduce this configuration for months and months and was eager to give it a shot. Aside from giving it a workout over the fall & winter, it's pretty likely to accompany me into the woods for calling coyotes.
http://img231.imageshack.us/img231/5663/bcmmiddyright.jpg
http://img242.imageshack.us/img242/4342/bcmmiddyleft.jpg
rgaper... very sweet rifle! Do you know the weight?
Almost identical to one on the way from BCM for me... except for stock and BC1.5Comp. Mine is a 14.5" std weight barrel, Mid-length w/11" VTAC TRX with BC1.5 comp and Troy folding BUIS.
I have been considering getting an A2 stock because I like the look and feel and your photos of your rifle just reinforce that. But I have read some reports that, at least, some of them are poorly made. May I ask where you sourced your A2 stock and what your impression is of its quality?
LonghunterCO
10-19-10, 07:47
rgaper... very sweet rifle! Do you know the weight?
Almost identical to one on the way from BCM for me... except for stock and BC1.5Comp. Mine is a 14.5" std weight barrel, Mid-length w/11" VTAC TRX with BC1.5 comp and Troy folding BUIS.
I have been considering getting an A2 stock because I like the look and feel and your photos of your rifle just reinforce that. But I have read some reports that, at least, some of them are poorly made. May I ask where you sourced your A2 stock and what your impression is of its quality?
His stock is a Cav Arms full stock (which is A1 length). I think that the stock shell is very well made, but the butt plate /trap door is cheesey. I don't really trust anything to stay in there with its loose door latch, so I just don't put anything in it. Not to fear, if you like the shell and the A1 length (as I do) then the butt/trap door can be replaced with a standard A2 setup.
His stock is a Cav Arms full stock (which is A1 length). I think that the stock shell is very well made, but the butt plate /trap door is cheesey. I don't really trust anything to stay in there with its loose door latch, so I just don't put anything in it. Not to fear, if you like the shell and the A1 length (as I do) then the butt/trap door can be replaced with a standard A2 setup.
Exactly right, it's the Cav Arms C1 buttstock. I don't have any strong feelings for the A1 or A2 buttplate or the trap door latch. The latch on the Cav Arms buttplate is far more positive than some of the USGI A1 buttplates I've seen.
If I like the setup of this upper, it may eventually move to my preban lower with a SOPMOD which I prefer. The A1 gives me the approximate length of pull that I regularly use with the SOPMOD, so it works. I put the upper on this postban lower with the A1 length because I planned to bring it to New York state over the winter and there's some argument over whether my preban lower is legal there or not. Not wanting to go through a New York state prison romance or wasting thousands of dollars defending myself, I decided to go the safest route and keep the setup postban.
I recently finished (https://www.m4carbine.net/showthread.php?p=790114) a build that I called lightweight. Until I saw some of the crazy light configurations posted in this thread.
Can't imagine how those feel. Mine is about 7.5 lbs with everything it would walk around with except the magazine (I haven't weighed it completed, yet) and the people who have handled it all comment how light it is, or ask if the internals are present.
I'm starting to think someone specifically selling extremely lightweight AR-15 components could do well for themselves...
Is there any way to trim weight from a UBR? I was wondering if it's possible to shave a bit from that beast; maybe remove the storage doors and hardware, integral sling attachments, etc...? It's by far my favorite stock but it's a damn beast of one at one and a half pounds.
-B
UsnRoberts
10-19-10, 22:10
Great build!:big_boss:
Robb Jensen
10-20-10, 04:12
Is there any way to trim weight from a UBR? I was wondering if it's possible to shave a bit from that beast; maybe remove the storage doors and hardware, integral sling attachments, etc...? It's by far my favorite stock but it's a damn beast of one at one and a half pounds.
-B
The doors weigh next to nothing. Most of the weight of a UBR is because the large amount of metal in it.
So the only way to reduce that weight is to use a different stock then. Damn. Thinking I need to reassess what's in mind to see if I'm really picturing a lightweight build.
-B
Robb Jensen
10-20-10, 18:15
So the only way to reduce that weight is to use a different stock then. Damn. Thinking I need to reassess what's in mind to see if I'm really picturing a lightweight build.
-B
Yep. I'd go either Magpul MOE or the old Colt CAR stock like I did on my wifes Project Featherweight. Her gun will very shortly be sporting a Battlecomp 1.5 perm. attached, she likes the FSC but doesn't like the additional blast and we shoot a lot indoors.
I'll post up new pics when I get it on there.
Wow, I'm a bit new around here, but this thread is great. Thanks for all the info everyone.
I decided my first AR build would be a light(er) weight carbine of sorts that I could truck around and use in classes and such at some point. I had hefted a buddy's AR with a mid-weight (standard) barrel setup and I remembered commenting to him that it was kinda hefty to lug around -- and he confirmed it was a bit of a bear when he was using it in classes.
I've been parting out my build and I seem to be hovering just over 7 lbs (no optic) based on paper... so we'll see how it turns out! I don't think I will be able to get down to the 5-6 pound feathers you guys seem to building up. Impressive!
On a related note, has anyone measured weight on the Aimpoint Comp C3 vs. the Aimpoint Micro T-1?
Dan Goodwin
12-23-10, 22:55
I never did put together a super LW, but have the fever again and saw this thread had resurfaced.
What is the weight diff between an A1 profile 16- and 20-in.?
Anyone got a weight on the Ace Ultra Light Modular Fixed Stock?
Just learned Green River is making 20-in. 8-twist chrome-lined A1s on the Vintage page. And of course several companies are marketing un-lined bbls in A1 profiel. Gettin' To' Up.
Diggin's Robb's wife's painted carbine. Gotta 7 oz. Leupold 2.5X on a Ruger Frontier right now, wondering how much it would weigh mounted with some non-tactical Weaver See-Thru rings...
Again, my purpose is a LW hunting rig...
I like that forearm. That looks cool.
Robb Jensen
01-15-11, 17:27
I added the perm. attached Battlecomp 1.5 and a VLTOR A5 receiver extension, Brownells chrome silicon standard rate rifle buffer spring and a VLTOR 5oz buffer.
http://img.photobucket.com/albums/v408/gotm4/IMG_8038.jpg
http://img.photobucket.com/albums/v408/gotm4/IMG_8039.jpg
http://img.photobucket.com/albums/v408/gotm4/IMG_8041.jpg
http://img.photobucket.com/albums/v408/gotm4/IMG_8040.jpg
How does it shoot with the A5 and Battlecomp 1.5? You've got me thinking of a lightweight build now too.
Robb Jensen
01-15-11, 17:58
How does it shoot with the A5 and Battlecomp 1.5? You've got me thinking of a lightweight build now too.
I'll be putting some rounds through it tomorrow.
Ilove2shoot
01-15-11, 19:32
OK, been wanting to work on these a little more, and this thread is motivating me. here are my favorite 2 Light Weight, K.I.S.S. rifles. You do not get simpler then Iron Sights, nothing to ever go out with them.
Cav-15 Mark II receiver.
20" A1 pencil barrel
Colt 601 receiver
Modified M16 carrier
Cav Rifle length FAT handgaurds. I like the feel of them.
Pinned on Cav Comp. (don't ask, this was originally done during the ban)
This rifle as it sits is 5lbs 15oz. with a 20inch barrel.
I am going to work more on the carrier and take a couple more Oz out of it. swap the break to a A1 flash hider. Use a set of Cav tapered rifle length HG (with will save 1.2oz). I think that those modifications should take out atleast 6 oz.
http://img17.imageshack.us/img17/4168/cav20lw.jpg
Cav-15 Mark II receiver.
16" pencil barrel.
Cav M4 handgaurds
Dan Young light weight carrier
Colt 601 receiver.
As it sits: 5lbs 8oz......
I want to cut the barrel back to 14.5 and attach a A1 flash hider, that will knock a couple ounces off.
http://img214.imageshack.us/img214/6403/cav16lw.jpg
How much of the gas block has to be shaved to fit under these. Shaving one to fit underneath my DD Lite was a pain, will this be worse or easier?
Stonerriflefan44
02-03-11, 19:56
I added the perm. attached Battlecomp 1.5 and a VLTOR A5 receiver extension, Brownells chrome silicon standard rate rifle buffer spring and a VLTOR 5oz buffer.
http://img.photobucket.com/albums/v408/gotm4/IMG_8038.jpg
http://img.photobucket.com/albums/v408/gotm4/IMG_8039.jpg
http://img.photobucket.com/albums/v408/gotm4/IMG_8041.jpg
http://img.photobucket.com/albums/v408/gotm4/IMG_8040.jpg
Is that a .75 barrel turned down to .625? from the pics it almost looks slightly smaller than a LW barrel. Awesome build btw.
Robb Jensen
02-03-11, 20:39
Is that a .75 barrel turned down to .625? from the pics it almost looks slightly smaller than a LW barrel. Awesome build btw.
It's a RRA .750" barrel turned down to .565". It's still .750" at the gas block and about .630" or so just behind the threads to give it a nice shoulder for the Battlecomp.
Robb Jensen
04-19-11, 20:43
Pic of it from the other day. 85.7 ounces (aka 5.36lbs)
http://img.photobucket.com/albums/v408/gotm4/Virginia%20Arms%20pics/ProjectFeatherweightApr142011.jpg
Robb
How is the recoil impulse on the uber lightweight with the A5? Is the 5oz the standard bufferweight?
I had 3 with my kits: unmarked, -3, -4
Robb Jensen
04-19-11, 21:13
Robb
How is the recoil impulse on the uber lightweight with the A5? Is the 5oz the standard bufferweight?
I had 3 with my kits: unmarked, -3, -4
Very soft.
A5 unmarked is 5oz (4 weights inside, 2 tungsten and 2 steel)
-3 = (A5H3) 6.3oz (3 tungsten, 1 steel)
-4 = (A5H4) 7.0oz (4 tungsten)
Modified A5 buffers are as follows, (you have to mod them yourself)
A5 Mod1: 4.5 oz (1 tungsten, 3 steel)
A5 Mod2: 3.6 oz (4 steel)
In Project Featherweight (with Battlecomp) and in my KAC SR15E3 (with Triple Tap comp) I'm using an A5 Mod1 4.5oz buffer which shoots very soft. In my 3gun rifle with a JP LMOS 6oz bolt carrier I'm using a A5 Mod2 (4 steel weights) but mine weighs 3.8oz on my cheapy digital scale.
Nice!
On the lightweight note, has anyone seen plastic/polymer port covers?
weight vs steel?
I can't remember where I saw one... I think it was on a new HK416
All I could find on the www http://www.opticsplanet.com/reviews/write-review-mako-group-adjustable-polymer-ejection-port-cover-for-ar15-m16-m4.html
So when are you starting the .308 Project Featherweight?
:D
Robb Jensen
04-19-11, 22:32
Nice!
On the lightweight note, has anyone seen plastic/polymer port covers?
weight vs steel?
I can't remember where I saw one... I think it was on a new HK416
All I could find on the www http://www.opticsplanet.com/reviews/write-review-mako-group-adjustable-polymer-ejection-port-cover-for-ar15-m16-m4.html
The MR223 has a plastic dust door which is probably 1/2 the weight of steel.
Mako has polymer ejection port covers here (http://www.makosecurity.com/Merchant2/merchant.mvc?Screen=PROD&Product_Code=PEC&Category_Code=_M16Misc) if its of interest.
Now here is a question...how bad of an idea is a factory Colt 6720? I would love to have something under 5 pounds and was looking at this being a pretty good out of the box option that tipps the scales at 4.7 pounds.
Now here is a question...how bad of an idea is a factory Colt 6720? I would love to have something under 5 pounds and was looking at this being a pretty good out of the box option that tipps the scales at 4.7 pounds.
The 6720 is a nice choice, but the weight is a typo. It's 5.7 lbs, not 4.7 (it's a 6520 with a flattop upper).
The 6720 is a nice choice, but the weight is a typo. It's 5.7 lbs, not 4.7 (it's a 6520 with a flattop upper).
Actually, both are wrong. A 6720 (right out of the box) weighs 6 lbs., 2.3 oz.
http://img.villagephotos.com/p/2005-5/1004431/Weight%28Colt6720%29.jpg
Thanks. Even 5.7# seemed a bit light.
Someone needs to inform Clyde Armory as their website lists the weight at 4.7 pounds.
http://clydearmory.com/colt-ar6720.html
jgcl05@yahoo.com
09-06-11, 13:51
This is a great writeup! I've had a brick of an AR for the past 2 years and I'm finally putting it on a diet. There's a lot of good info and inspiration here. First my UBR is coming off, then my barrel is getting turned down. Thanks for all the info Robb!
4.5 lbs as pictured:
http://rentbear.net/pix/cav15.jpg
http://rentbear.net/pix/cav15wt.jpg
did anyone ever do that light weight chart?
Lost River
09-10-11, 06:16
I built this a while back. Intended mostly as a hunting carbine. It has turned out to be a true joy to carry afield. It balances perfectly and swings easy.
http://i18.photobucket.com/albums/b109/IV_Troop/0042.jpg
http://i18.photobucket.com/albums/b109/IV_Troop/0112.jpg
Lost River
09-10-11, 06:23
It has turned out to be THE rifle that is quite handy to have along when packing in to places or setting up a camp:
http://i18.photobucket.com/albums/b109/IV_Troop/039-2.jpg
http://i18.photobucket.com/albums/b109/IV_Troop/045.jpg
http://i18.photobucket.com/albums/b109/IV_Troop/063.jpg
Lost River
09-10-11, 06:29
http://i18.photobucket.com/albums/b109/IV_Troop/AlexDadMe026.jpg
IMO, that's a damn near perfect coyote rifle. Glad to see you're putting it to good use!
What's the approximate weight?
I built this a while back. Intended mostly as a hunting carbine. It has turned out to be a true joy to carry afield. It balances perfectly and swings easy.
http://i18.photobucket.com/albums/b109/IV_Troop/0042.jpg
http://i18.photobucket.com/albums/b109/IV_Troop/0112.jpg
Lost River, what profile barrel?
Lost River
09-11-11, 17:31
It is a White Oak 7 twist that I had turned down to a pencil"ish" profile.
Lost River
09-11-11, 17:50
IMO, that's a damn near perfect coyote rifle. Glad to see you're putting it to good use!
What's the approximate weight?
gfelber,
I weighed it when I built it, but I really cannot recall off the top of my head now. Calling coyotes is one of my favorite winter time activities and having a lighter weight AR to carry between sets is awfully nice.
Using the same upper on a different lower I had just built, I called this guy in:
http://i18.photobucket.com/albums/b109/IV_Troop/MackayJun16-20008.jpg
Great build, turned out fantastic.
Lost River
09-15-11, 21:41
Thanks,
It really carries nicely. When you are wading through knee deep snow with a pack and are working up a sweat, it makes a guy really appreciate a light little rifle that carries so well and balances easily in one hand.
This last spring I pulled a sled full of stuff into my little cabin (which is a work in progress)since the snow made driving not an option. Being able to sling the light little AR across my chest, so I could pull with both hands made the task much simpler.
http://i18.photobucket.com/albums/b109/IV_Troop/025-4.jpg
Anyone who is looking for a sling to go with their lightweight AR needs to have a hard look at the Sheriff of Baghdad sling offered by Mission Ready Equipment.
I picked one up after the SHOT show and it feels like 1/2 the weight of a VTAC or Vickers sling. Very little metal, and I suspect a sling swivel weighs more than the material used in the sling. It's designed by a hard hitter.
I also like the fact that there is no "tail" at the muzzle that can get snagged.
http://www.missionreadyequipment.com/tactical-equipment/weapon-accessories/slings/sheriff-of-baghdad-b-sling
I'm using a CAR buffer (3oz), so far 100% reliable, 1200 rounds fired, 600 rounds of that Radway Green 62gr (SS109 projectile).
Hello Robb, hope you can answer some questions:
How's the Rifle holding up with more rounds thru it?
courious if the JP lmos can stand up to hot ammo.
I'm in the process of building a rifle for a 14yo Girl, a basic KISS/Light Weight carbine with mid gas system and is considering that carrier..
-Any thoughts?
SpankMonkey
09-12-12, 00:42
I would love to hear a follow up. Any changes to the rifle?
Robb, 3 more ounces gone here:
http://militarytimes.com/blogs/gearscout/2012/09/26/the-lightest-lightweight-ar-lower-receiver/
And possibly more weight cut from the irons
http://lightfighter.net/eve/forums/a/tpc/f/7206084761/m/76120641963?r=95120462963#95120462963
Magic_Salad0892
09-28-12, 01:26
Here's what I'm thinkin'. Maybe somebody can chime in.
Upper: Rock River 9x19mm Upper + gas tube hole drilled in, and M4 feed ramps. (Probably ADCO work)
Lower: MAG Gen4 Tactical Systems LW Lower (mentioned above)
Sights: KAC Micro 300 rear, and micro front.
Rail: KAC 8'' URX III
Barrel: DD 16.1'' LW CAR barrel, cut to 10'', gas port unmodified.
BCG. JP LMOS carrier + Colt Bolt
Receiver extension: Colt/LMT
Stock: Colt N-1 CAR stock.
Buffer: CAR
Trigger Guard: Magpul MOE polymer trigger guard.
Spring: Sprinco WHITE CS spring.
Sling attachment point: Noveske single point endplate.
Magazing catch: Arredondo magazine catch. Polymer.
Sling: SoB sling. (Mentioned above. I've seen 'em in person, they've been around for a while, and Kyle Defoor speaks highly of 'em. I can't remember if you could use a Mount-N-Slot with 'em to make 'em a singlepoint. If possible. I'd do it.)
Muzzle Device: Micor Titanium FH 1:7 twist
Gas Block: Forged Pinned FSB. Colt if possible. Shaved to low pro block, cut in half using only rear half.
Pistol Grip: Magpul MOE+
CH: BCM gunfighter
I'd remove the ejection port door completely, as I remove it from all my ARs.
I'm wondering what a setup like that would weigh in at, and if it'd be reliable.
Mine is close to that recipe, but unlike the forward assist, I find the dust cover to be useful. I have a Mako plastic dust cover with a V7 aluminum rod, and it adds very little weight. Don't have a weight yet, but it's light.
http://i39.photobucket.com/albums/e200/eodinert/guns/da946c50-8816-4fb7-af34-ddd1a936255d_zpsf8cd5500.jpg
Here is my post with more info: https://www.m4carbine.net/showthread.php?137888-V7-Weapon-Systems&p=1875858#post1875858
LonghunterCO
03-18-14, 17:04
Anyone try the lower V7 lower parts in one of the older CavArms lowers?
Cool, I am in the process doing a similar project to yours.
FWIW, the mako dust cover and the JP low mass bolt carrier don't play well together. The lump on the inside of this dust cover is shaped for the big scallop on the milspec bolt carrier, and the JP has a very small scallop. Being plastic and all, it won't be rocket surgery to fix, but fix it I must... as it sits, the dust cover will not close.
That rifle has almost all of the V7 kit on it, except for the selector (which I have, and will be installed), and the gas block (which I didn't use because it's not adjustable, and I need to choke down the gas for the low mass BCG and superlight buffer).
Robb Jensen
06-24-14, 22:46
Updates to Project Featherweight:
10" BCM KMR rail, BCM upper receiver, X7Weapons 57degree safety, titanium takedown pins, aluminum mag catch assy, aluminum castle nut and QD end plate.
http://img.photobucket.com/albums/v408/gotm4/imagejpg1-10.jpg
http://img.photobucket.com/albums/v408/gotm4/imagejpg3-1.jpg
http://img.photobucket.com/albums/v408/gotm4/imagejpg1-9.jpg
http://img.photobucket.com/albums/v408/gotm4/imagejpg2-1.jpg
Updates to Project Featherweight:
10" BCM KMR rail, BCM upper receiver, X7Weapons 57degree safety, titanium takedown pins, aluminum mag catch assy, aluminum castle nut and QD end plate.
Robb, I have always enjoyed this thread and the the builds progression. But I have to ask, if changing uppers, why the change to another one build for a forward assist? Aero amongst others make a very reasonably priced upper with no forward assist.
Thanks,
-Theo
Robb Jensen
06-26-14, 13:58
Robb, I have always enjoyed this thread and the the builds progression. But I have to ask, if changing uppers, why the change to another one build for a forward assist? Aero amongst others make a very reasonably priced upper with no forward assist.
Thanks,
-Theo
Just happened to be what I had on hand without buying another receiver.
Moonlight Again
06-28-14, 16:02
Robb, this is one of my favorite threads, ever----not only at M4C, not only about the AR15/M4, but ever. (A long thread on handmade kilts edges it, but hey.) It's great to hear you're still running it.
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