BCM Carbine with 13" KMR LW Upper [Archive]

Iraqgunz

03-26-14, 02:46

For those that are interested in the weight of a basic type carbine I weighed the upper recently acquired BCM 13" KMR LW Carbine. The components are as follows;

1. 16" LW Midlength barrel with the BCM MOD 0 Compensator

2. 13" KMR Rail with (1) polymer rail segment.

3. BCM Gunfighter vertical grip (partially chopped)

4. BCM Diamonhead front and rear sights.

5. BCM BCG and MOD 4 Gunfighter.

6. BCM Lower Receiver Half with H buffer and BCM MOD 1 grip.

7. B5 Systems Bravo Stock.

Total weight of the carbine as configured after 3 separate weightings on the scale was 6 lbs. 3.8 oz. If you substituted a few things weight would probably drop down to just under 6 lbs.

2468124682

teutonicpolymer

03-26-14, 03:16

I like it. I am eager to see a 12" kmr that works with rifle length front sight posts. Otherwise maybe I'll just have to get a 13" and pop it in the milling machine.

SpankMonkey

03-26-14, 05:17

Cute stick IG. What optic are you going to run? How do you rate the kmr?

I have a range toy down to 5lbs, 11ozs. No iron sights but have a micro sitting on top. Damn handy rife for long walks through the woods.

Eurodriver

03-26-14, 06:23

Is this your rifle IG? I always thought you and I were the last remaining non vert grip holdouts.

Thanks for the report!

NeoNeanderthal

03-26-14, 08:01

Im sure the ELW fluted version, minus the vert grip would get you under 6lbs. Crazy light, thanks for posting.

bullittmcqueen

03-26-14, 08:09

Sub-6 pounds is doable IG. My rifle is almost an exact build of yours except with a 14.5 LW and no VFG. 5-14 with the 13" KMR

24692

markm

03-26-14, 08:20

Is this your rifle IG? I always thought you and I were the last remaining non vert grip holdouts.

Thanks for the report!

Last couple times he made it out to shoot, he was fore gripped. I gave him an infraction.

samuse

03-26-14, 09:38

Is this your rifle IG? I always thought you and I were the last remaining non vert grip holdouts.

Thanks for the report!

I thought those things were deemed unpopular years ago.

Eurodriver

03-26-14, 10:09

I thought those things were deemed unpopular years ago.

I can't keep up with what the internet thinks, but I remember years ago making a post about how much I hate VFGs and IG agreed with me.

Then about a year ago I got a Magpul stubby for free and I haven't looked back. Grabbing the forearm by pulling the VFG into your shoulder and wrapping the left thumb over the top provides so much more control than without, and your ability to shoot from cover/prone isn't compromised nearly as badly as it was with the long VFGs of the old school days. And as evidenced by IG's pic, they don't even add much weight. His rifle has a 1.5" longer barrel, heavier barrel profile and a VFG and it still weighs only 4oz more.

Mark, you already have the Costa beard, why don't you climb aboard the Magpul 21st Century bro? ;)

markm

03-26-14, 10:57

Mark, you already have the Costa beard, why don't you climb aboard the Magpul 21st Century bro? ;)

SCORPION!!!!

samuse

03-26-14, 11:56

Agreed, a VFG is ok for shooting standing, it makes a good handstop or whatever.

But to me a VFG or any unnecessary bs like AFGs, rail covers, hand stops, tape switches, or anything just gets on my nerves, gets in the way of a hand when I'm already in a bind, hangs up on anything and everything associated with vehicles or doing anything with the gun slung and no hands on the gun.

Iraqgunz

03-26-14, 12:53

I actually use vertical foregrip on some of my rifles. I prefer to have a short stubby grip and I'm not a big fan of the AFG. I've got a couple that I modified like the one in the picture and I also have a couple of the Tango Down stubby grips with the Elite Defense quick release mechanism.

I can't keep up with what the internet thinks, but I remember years ago making a post about how much I hate VFGs and IG agreed with me.

Then about a year ago I got a Magpul stubby for free and I haven't looked back. Grabbing the forearm by pulling the VFG into your shoulder and wrapping the left thumb over the top provides so much more control than without, and your ability to shoot from cover/prone isn't compromised nearly as badly as it was with the long VFGs of the old school days. And as evidenced by IG's pic, they don't even add much weight. His rifle has a 1.5" longer barrel, heavier barrel profile and a VFG and it still weighs only 4oz more.

Mark, you already have the Costa beard, why don't you climb aboard the Magpul 21st Century bro? ;)

BrigandTwoFour

03-26-14, 14:55

I like it. I am eager to see a 12" kmr that works with rifle length front sight posts. Otherwise maybe I'll just have to get a 13" and pop it in the milling machine.

+1 on this. I've been wanting to get a 20" government upper to slap on my A5-equipped lowers for shits and giggles. I was planning on going with the MOE handguards until I could install a Centurion C4, but if a 12" KMR comes out for use in this configuration, then BCM will have my money (well...I suppose they're getting it either way, but they'll get more with the KMR)

cougar_guy04

03-26-14, 19:16

Rayrevolver

03-26-14, 20:00

That's got me to wondering how much more weight could be taken out of the base rifle. I know it's chasing ounces, but I wonder just how light you could get a 16" AR. Sub 7# with optic, sling and light would be a nice little setup (IG's gets pretty close, if not there, it looks like)

All these KMR posts are seriously making me consider building a rifle or two up with one.

You could get closer to 6 lbs even, if you tried really hard.

Here is my carbine (16" ELW, no flutes) with everything except a QD mount for the rail and a sling attached, it weighs 6.85 lbs (6lbs 13.6oz). I have since removed the Bravo B5 and put on an MFT minimalist so subract 2.9 oz. The Noveske Gen 2 lower is supposedly 1 oz heavier than a standard lower. I have a DD mount for the Micro which would save another 2 oz over the ADM I currently use.

I also have KAC BUIS but I am not sure if they are lighter than the fixed DD set.

I just need to get the IWC QD sling mount and wait for the keymod short VFG and I am all set.

BufordTJustice

03-26-14, 22:33

That's got me to wondering how much more weight could be taken out of the base rifle. I know it's chasing ounces, but I wonder just how light you could get a 16" AR. Sub 7# with optic, sling and light would be a nice little setup (IG's gets pretty close, if not there, it looks like)

All these KMR posts are seriously making me consider building a rifle or two up with one.

Swap your ejection port cover, forward assist, and magazine catch for some V7 parts like i did. ;)

I have an 18" gov profile barrel with rifle gas, 13.5" kmr, AFAB mini, IWC qd sling mount, Vltor A5 system, B5 bravo stock, Magpul bad lever, Magpul K2, BCM gunfighter mod 4, micro t1 in an lt660, and Magpul mbus gen2's (and the listed v7 parts)......weighs 6.87lbs.

Crazy light.

Sent from my SPH-D710 using Tapatalk

TXinfidel

03-27-14, 00:22

Koshinn

03-27-14, 00:34

That's got me to wondering how much more weight could be taken out of the base rifle. I know it's chasing ounces, but I wonder just how light you could get a 16" AR. Sub 7# with optic, sling and light would be a nice little setup (IG's gets pretty close, if not there, it looks like)

All these KMR posts are seriously making me consider building a rifle or two up with one.

There's a post on TOS with some of the lightest weight parts lists...

You can probably get there with the Mag tactical magnesium upper and lower receivers, a KMR, 14.5 ELW BCM barrel, V7 misc parts, a Magpul K2 grip, a CAR fiberlite stock, VDI Manimal FH pinned, a Trijicon RMR as your primary optic, and a x300 or TLR-1 at 12 o'clock. Getting sub-7#s is easy. Getting sub-6#s isn't when you want an optic and light, since at that point, you've already cut the major weight items and you're now shaving an oz here and there, if that.

markm

03-27-14, 09:01

IG, how would you feel about hanging a can on this setup? I have a 14.5 BCM ELW Fluted with Keymod13 sitting at my dealer that I ordered from Grant. I just don't have enough time with LW barrel to know about sustained use with say an SF Socom or AAC SR5

Not sure what Gunz thinks, but my 14.5 ELW just doesn't seem like an optimal can host. I have the permed Gunfigher flash hider, and I'm leaving it. See... the light weight barrel with no can heats up pretty quick... but it cools off much faster than a standard barrel too.

Another concern would be barrel droop. It'd have to be a light can, like a mini 4 or something to make is slightly doable in my opinion.

Iraqgunz

03-27-14, 16:56

I had a can on a 16" Noveske, but I don't think I would want to hang something like my M4-2000 on a lightweight barrel. Maybe something smaller, but it's one of those things that probably needs to be tested.

IG, how would you feel about hanging a can on this setup? I have a 14.5 BCM ELW Fluted with Keymod13 sitting at my dealer that I ordered from Grant. I just don't have enough time with LW barrel to know about sustained use with say an SF Socom or AAC SR5

TXinfidel

03-29-14, 03:48

Ya, I am having trouble finding any reliabe data on this, I started a thread in the NFA section to see if anyone has any info. I could see maybe an AAC mini4 but I always think about the 1/4lb flashhider/mount that has to be added to it.

Iraqgunz

03-29-14, 04:06

Not sure how you could add a light, optic and sling and keep it ultralight. I did weigh it with an X300 and Aimpoint T1 in BOBRO mount and it came in around 6 lbs. 11 oz. That's still under 7 lbs. I think some people are really over obsessing about the weight.

That's got me to wondering how much more weight could be taken out of the base rifle. I know it's chasing ounces, but I wonder just how light you could get a 16" AR. Sub 7# with optic, sling and light would be a nice little setup (IG's gets pretty close, if not there, it looks like)

All these KMR posts are seriously making me consider building a rifle or two up with one.

Iraqgunz

03-29-14, 04:07

Then you get something that direct attaches like the Ranger-3 or maybe the Gemtech Trek-T.

Ya, I am having trouble finding any reliabe data on this, I started a thread in the NFA section to see if anyone has any info. I could see maybe an AAC mini4 but I always think about the 1/4lb flashhider/mount that has to be added to it.

Trajan

03-29-14, 10:50

Not sure how you could add a light, optic and sling and keep it ultralight. I did weigh it with an X300 and Aimpoint T1 in BOBRO mount and it came in around 6 lbs. 11 oz. That's still under 7 lbs. I think some people are really over obsessing about the weight.

If anyone complains about weight with a KMR and ELFW, then they seriously should start lifting. With the base gun with the new MBUS Pros, the weight is barely more than merely lifting your arm up. Senior citizens at the YMCA lift more than that...

People will always complain though.

Nice gun dude.

jerrysimons

03-29-14, 12:10

https://www.m4carbine.net/showthread.php?146386-Noveske-Ultralight

Easily sub-6lbs if I put a 13" KMR on this rifle to replace the 11" NSR. At 2" longer and 2oz lighter (7.7oz vs 9.8oz) BCM really knocked it out of the park with the KMR. I don't plan on changing handgaurds though.
To that end however, project uberlight, is coming along well with a 14.5" ELWF and 10" KMR, projected to be in the low 5lbs region.

cougar_guy04

03-29-14, 20:16

Not sure how you could add a light, optic and sling and keep it ultralight. I did weigh it with an X300 and Aimpoint T1 in BOBRO mount and it came in around 6 lbs. 11 oz. That's still under 7 lbs. I think some people are really over obsessing about the weight.
6 lb 11 oz would be a lot lighter than the ones I'm running now. Never really thought of them to be that heavy, but I'm guessing they're on the porky side for a 5.56 rifle.

As for the weight, I guess I'm just geeking out over the weight because I'm kind of excited to see what new materials could do for gun & accessory design.

FChen17213

03-29-14, 21:27

Iraqgunz is absolutely right. I think people are starting to over obsess with tenths of ounces here. It is awesome that the KMR shaves several ounces off the weight of the gun and provides an awesome lightweight rail. However, people should get what they like, not something else just because it is .3 ounces lighter. Lighter weight is usually good, but if you gain something with that increased weight or have additional capability, it is sometimes worth it. One example, at least that i found out for myself dealt with optics. I had a T-1. Then i realised that i could get a Trijicon RMR and save even more weight. After getting the RMR, i found out that the weight savings was not worth it. For me, the T-1 was a far better optic for me. If there is something to be gained from the weight, it could be worth it. A most extreme example would be having sights on a gun period. We can save weight by getting rid of sights and optics altogether. I don't think there is a single shooter out there who would say that it's smart to save weight by removing sights altogether. We don't want to start sounding like, "Do these jeans make my ass look fat?" I guess.

Zane1844

03-29-14, 21:32

I have the 13" KMR Fluted ELW upper, Troy sights, a SureFire G2X in a HSP Thorntail mount, Vltor A5, and a Vortex Razor 1-6x. It is just about 9 pounds.

If I take the scope off, I am looking at 7 pounds.

9DivDoc

03-29-14, 22:26

buckkiller35

04-06-14, 01:46

That's a very nice rifle. I just got a 16" BCM BFH lw middy and put the 12" Fortis rev rail on it and it is around the same weight as yours. I love it!

markm

04-07-14, 09:24

I'd like to tinker with the BUIS on your upper. I can't get my POI up high enough, and my FSP is buried in the sight tower. The rail is mounted straight as an arrow. We need to shoot.

Zane1844

04-07-14, 09:29

I'd like to tinker with the BUIS on your upper. I can't get my POI up high enough, and my FSP is buried in the sight tower. The rail is mounted straight as an arrow. We need to shoot.

Markm is this with the ELW upper?

markm

04-07-14, 09:36

Markm is this with the ELW upper?

Yeah... I'm almost never running the BUIS so it's not been an issue. But I think the Rear app is low. I mounted it in front of a cut down carry handle, and the small app is visibly lower than a USGI app when bottomed out.

I was all but certain the back sight was low until I tried one of the KAC USMC flip ups. It matches the Diamondhead pretty closely. But I think I can remember having to spin that KAC sight up to get it into reality.

I don't have a way to check the Front sight accurately.... so I'm going to have to move irons back and forth to see if I can conclusively find out which sight isn't playing well. I can shoot great groups on paper with the sights... just that the POI is too low.

Zane1844

04-07-14, 09:44

Yeah... I'm almost never running the BUIS so it's not been an issue. But I think the Rear app is low. I mounted it in front of a cut down carry handle, and the small app is visibly lower than a USGI app when bottomed out.

I was all but certain the back sight was low until I tried one of the KAC USMC flip ups. It matches the Diamondhead pretty closely. But I think I can remember having to spin that KAC sight up to get it into reality.

I don't have a way to check the Front sight accurately.... so I'm going to have to move irons back and forth to see if I can conclusively find out which sight isn't playing well. I can shoot great groups on paper with the sights... just that the POI is too low.

Interesting, the rear sight and Aimpoint on my Fluted ELW upper needed to be adjusted pretty far to the left. I can also shoot pretty good groups with mine.

I am still worried I tweaked the barrel putting the comp on, but the windage is not maxed out, and it holds zero and shoots fine.