View Full Version : Question for BCM 14.5 Mid users
I noticed on the BCM website that there is an advisory for these barrels; full-power ammo is recommended, apparently for reliable functioning. The advisory says to use an H buffer; carbine buffer recommended for lighter loads. This makes me wonder if there might be an issue due to the shorter length of barrel in front of the FSB on the 14.5 middys. It's probably a non-issue (website says the 14.5 mid setup is 'specifically tuned', presumably to avoid any issues) but I am curious about it nevertheless and would like to hear from users on any issues thusfar. Still trying to decide on a middy upper, definitely going BCM but will it be the 14.5/perm A2X, or a 16 LW or standard. Thanks in advance! ;)
I have exactly one mag through this setup, and it was 28 rounds of Black Hills 75 grain blue box. It ran like a champ, with almost no muzzle rise, for all 28 rounds.
I'm going to try it with Wolf 62 grain and see what happens, and play with the buffers as well.
shittercrewchief
04-28-10, 16:04
I'm gonna run some federal xm193 through mine this weekend.
And also some PMC 55gr. which is known to be light powered.
Will post results sat night.
I've got a CMMG LW 14.5" Middy and I haven't had a single problem in the 500 rounds I've put through it. I'm using an H buffer and a semi-auto carrier with a BCM bolt upgrade.
So far I've put Wolf, Old Norinco chi-com crap,Remington UMC, Win 3131, Black Hills 77gr, and M855 through it without a single hiccup.
My bud Skinja has one of these and I only fired 20 rounds of XM193 through it - side by side with my N4 Recce and the lack of recoil impulse on the BCM was very noticeable compared to my 16" mid length. Very impressive. Not sure what other ammo he's tried in it yet however.
I've got a CMMG LW 14.5" Middy and I haven't had a single problem in the 500 rounds I've put through it. I'm using an H buffer and a semi-auto carrier with a BCM bolt upgrade.
So far I've put Wolf, Old Norinco chi-com crap,Remington UMC, Win 3131, Black Hills 77gr, and M855 through it without a single hiccup.
I'm not sure this is a 1:1. I would bet that the CMMG has a larger gas port than the BCM, and if it ran Wolf I would bet that's the case.
ejeffreyhorn
04-28-10, 19:26
I have 2200 rounds through mine including 1500 over a 3 day carbine course. All ammo was Centurion M193 brass cased 55gr except for a few federal 69gr rounds I had. No problems. My buffer isn't marked as an H buffer. I might be an "H," but at this point I can't even remember where it came from.
And, I will add, this setup is fantastic. It is light, fast and has the recoil of a mouse fart. :D
Was doing some chronographing through my BCM 14.5" mid a couple weeks ago, this is a new rig with only perhaps 75 rounds through it at the time. I can say it was functioning just fine with a mag full of Hornady 55 gr. TAP. This stuff was clocking a measly 2650 fps, while both the Federal xm193 and IMI 193 were running a good 350 fps faster.
I sheepishly admit I don't know what buffer is in the lower, it's a full S&W lower purchased from G&R, for what that's worth.
I will say that this rig shot noticeably smoother than my stock Colt 6920. Great upper.
Dan
I'm not sure this is a 1:1. I would bet that the CMMG has a larger gas port than the BCM, and if it ran Wolf I would bet that's the case.
I wouldn't doubt it at all. What would be the benefit of BCM using a smaller gas port? I know they know their shit, so there's probably a good reason.
hey- i have run 500 rds thru mine, 14.5mid ddfspm,s/f f.h., have run xm193,77grn b.h.,62grn ss109, 52grn fed and wolf 55 an 62 grn junk,EVERYTHING WORKs!! i run a lmt factory lower with a standard car buffer was going to put in a H but don't really see the need, i run a lwrc m6a2 stretch with same results[h2 buff] but for the money the 14.5bcm is the best carbine i have run in over 20years behind a rifle, when i can swing it i will build #2 and have some identical goodness,also as JHC[joe] says there is NO muzzle flip[rise] and i am using a standard surefire flash hider,really great ,lite ,fighting rifle.thanks for listening,T sure if you ask joe will post some pics of my build for ideas
RetreatHell
04-28-10, 21:17
I only have 570 rounds through my BCM 14.5" mid-length upper so far, 150 of those rounds were fired with my surefire suppressor attached, and I haven't had a single issue.
Ammo used was 370 rounds of Hornady 55gr Training ammo, and 200 rounds of PMC 55gr.
Thing is, I just now went and checked to see what weight buffer I had in there because I couldn't remember right off hand, and this ENTIRE time I've been using an H2 buffer by mistake. I thought it was a carbine or H1 this whole time:p Guess I'll just go ahead and keep it in there for now.
Anyhow, this upper is one smooth shooting bitch, that's for sure.
Robb Jensen
04-28-10, 21:35
Suppressed an H2 will be fine on a 14.5" BCM midlength. Mine will run with a H3 suppressed.
RetreatHell
04-28-10, 21:47
Suppressed an H2 will be fine on a 14.5" BCM midlength. Mine will run with a H3 suppressed.
Yeah I know, I was mainly talking about the other rounds I fired unsuppressed. All in all, I'm really digging this carbine!
I wouldn't doubt it at all. What would be the benefit of BCM using a smaller gas port? I know they know their shit, so there's probably a good reason.
Smaller gas port equals less recoil and less wear on the gun.
C4
And also some PMC 55gr. which is known to be light powered.
That'll be a good test. That Bronze is about the weakest factory ammo you can get.
Interested to see if it runs wolf OK.
I'll buy when they get a 14.5 LW middy out. Considering they can't keep the regular LW middy in stock, I'll hold my breath at my own peril.
Robb Jensen
04-29-10, 06:51
And also some PMC 55gr. which is known to be light powered.
That'll be a good test. That Bronze is about the weakest factory ammo you can get.
My BCM 14.5" optimized gas system gun runs just fine on PMC. I'm using a CMT H buffer, LMT enhanced carrier with a BCM carrier key, BCM bolt, cam pin and firing pin and with PMC it locks back every time. With the AAC Brakeout it shoots very soft with very little muzzle rise.
The next ammo I need to try is Wolf, Remington/UMC and Radway Green.
david.bergen
05-13-10, 15:03
Can somebody give me some gas port sizes for a 14,5 midlength barrel. So we can compare the different brands
Can somebody give me some gas port sizes for a 14,5 midlength barrel. So we can compare the different brands
14.5" middy barrel gas ports can be anywhere as there is no set standard.
Companies like BCM and Noveske are typically going to use smaller GP's.
C4
david.bergen
05-13-10, 16:13
What range are we talking here ?
Smallest to largest?
What range are we talking here ?
Smallest to largest?
Hard to say. You would have to own all the barrels out there (that are in this config) in order to get a range.
C4
david.bergen
05-13-10, 16:36
I am going to turn my own from a barrel blanc and was wondering about gas port sizes. I live in Belgium (europe) and getting parts is very difficult. We are trying building our own stuff.
Robb Jensen
05-13-10, 16:42
I am going to turn my own from a barrel blanc and was wondering about gas port sizes. I live in Belgium (europe) and getting parts is very difficult. We are trying building our own stuff.
Start at .0625"-.063" and go up from there until it works reliably. That's the size of a Mil-spec gas port on a CAR gas 14.5" M4 barrel.
Most commerically produced midlength barrels are from .085"-.100" and most are way overgassed.
david.bergen
05-13-10, 16:58
So when I start with the carbine size port and the weakest ammo. (wolf 55) It shouldn't work. If I then enlarge till BCG locks to the rear
I am good to go. If I start with a carbine buffer I always can go to a heavier buffer for shooting mil spec ammo. Is this the correct thinking?
When testing the rifle should I set it very firm in the shoulder or use a very loose grip. We found it makes a difference when adjusting the gasblock on a IPSC rifle.
We bought a 14.5" middy from BCM to update an old M16-A1 at work. The gun ran great with about 500 rounds of Federal 55 grain 5.56mm FMJ. This was with a rifle buffer. I've not shot it another officer had it for a two day pistol/carbine class. Our guns ran great it made me smile, 3 LMT SBR's and this BCM SBR.
My BCM 14.5" optimized gas system gun runs just fine on PMC. I'm using a CMT H buffer, LMT enhanced carrier with a BCM carrier key, BCM bolt, cam pin and firing pin and with PMC it locks back every time. With the AAC Brakeout it shoots very soft with very little muzzle rise.
The next ammo I need to try is Wolf, Remington/UMC and Radway Green.I had a question..., does optimized gas system mean that the gas port was optimized for the type of ammo you wanted to run?
Robb Jensen
06-12-10, 11:03
I had a question..., does optimized gas system mean that the gas port was optimized for the type of ammo you wanted to run?
No. It's optimized for a 14.5" barrel using a midlength gas system, it works with 5.56mm NATO ammo and .223 Rem (SAAMI spec) ammo. It has a smaller port than other midlength barrels. Just enough to run and not short stroke which makes is shoot very soft. It runs a lot cleaner and a tad cooler as well. I'm using a H buffer with mine along with an AAC Brakeout comp/flash hider.
For bolt carriers I'm using it with a BCM M16 BCG. It shoots incredibly soft. Getting an AR to be reliable and shoot soft is a fine science. Too much gas and it'll run with weak ammo. Too little and it'll short stroke. Too heavy of a BCG and it can short cycle, too light and it runs out of rearward momentum too soo and also won't feed as well. The optimized BCM uppers are meant for a .223 and 5.56 with M16 BCGs and H or CAR buffers. Combined with a comp like a KAC Triple Tap or PWS FSC556 makes for a really nice soft shooting upper which is dead nuts reliable. Mine has a BCM hammer forged barrel.
My 3gun rifle is also 'optimized/tuned', it's a BCM 16" midlength SS410, pinned VLTOR stainless gas block, BCM M16 BCG, Surefire muzzle brake (MB556AR), and a BCM H buffer.
My 12.5" BCM is also very soft shooting, it's a standard BCM chrome lined barrel with CARbine length gas. I pinned a Troy gas block on it. Installed a 11" Troy/VTAC FF tube. Installed my KAC Triple Tap, BCM M16 BCG, BCM H buffer. It shoots very soft with .223 pressure ammo or 5.56mm NATO pressure ammo. I sighted in it with Mk262 last night at 50yds and from the Federal AE223 55gr 50yd zero it only needed 1 click of windage to correct the POI. I'm using an Aimpoint C3 2MOA in a LaRue LT150 mount, DD fixed front sight and a BCM/Troy flip down rear sight.
RetreatHell
06-12-10, 12:40
I friggin' LOVE my 14.5" BCM Middy! It just feels, right. If that makes sense?
Here's mine in action (http://www.youtube.com/watch?v=SXJqDUEMClQ) from when me and thopkins22 went out to the range 2 days ago. It's me running a modified version of the Magpul Dynamics BSA Drill (I was limited to a 25-yard range), running my 14.5" BCM middy and using my new (well, "new" to me anyways) ContourHD 720p helmet cam to record the video.
GotM4
How is your AAC attached? Is it on an SBR? I'd like to perm my AAC and was thinking of doing it myself. I read a how to article about using Brownells heat stop paste and silver solder. I'd like the freedom to put it on a non SBR lower. The ability to have it reversed w/o damage as a plus too. What would you charge to do it for me? Looks like I could have it done professionally for about what I'd spend in gear and I'd know it was done right.
Thanks
i have the bcm 14.5 mid with a pws and H buffer and it ran 50 rds of .223 soft point with no hiccups.
Would anyone know if DD's HF 14.5 middy is tuned the same way as BCM's in terms of gas port size?
Robb Jensen
06-12-10, 20:13
T
GotM4
How is your AAC attached? Is it on an SBR? I'd like to perm my AAC and was thinking of doing it myself. I read a how to article about using Brownells heat stop paste and silver solder. I'd like the freedom to put it on a non SBR lower. The ability to have it reversed w/o damage as a plus too. What would you charge to do it for me? Looks like I could have it done professionally for about what I'd spend in gear and I'd know it was done right.
Thanks
It just threaded on sitting on one if my SBR lowers.
That'll be a good test. That Bronze is about the weakest factory ammo you can get.
Weaker than Wolf?
Weaker than Wolf?
Although I've shot a little of both, I've never compared the two.
I've got a Sabre 14.5 middie that I built up during the drought and it runs on most anything with an H buffer. I mosly shoot Remington and PMC bronze. Wolf runs better with a carbine buffer.
I recently bought an BCM 14.5 middie and it runs the same with the H buffer, just not as many rounds through it yet.
RetreatHell
06-14-10, 22:39
Although I've shot a little of both, I've never compared the two.
The Wolf ammo is mainly just so darn inconsistent. You never know if the batch you just bought is gonna be gtg or weak as hell and have short-stroking issues.
I don't personally think PMC is exactly that weak, although it sure as hell ain't "hot" ammo by any stretch of the imagination. I guess you could say its one of the weakest loads out of all the quality ammo available. But the main thing that's important to me with PMC is that you know what you're getting b/c it's consistently a little on the weak side.
Regardless, even though I wasn't always like this, I'll pretty much shoot whatever in my guns.
Cascades236
06-15-10, 01:27
ran about 500-ish rounds of XM193 thru it flawlessly, using a carbine buffer too
I don't personally think PMC is exactly that weak, although it sure as hell ain't "hot" ammo by any stretch of the imagination.
Its velocity is pretty low, and it short strokes in a few of the M4carbine.net members 20 inch guns... including mine.
It could partially be a funky burn rate propellant too.
RetreatHell
06-15-10, 19:44
Its velocity is pretty low, and it short strokes in a few of the M4carbine.net members 20 inch guns... including mine.
It could partially be a funky burn rate propellant too.
Although it could be important to some, velocity isn't an issue to me with training ammo. Not sure if it should be or not, but it's not something that's ever crossed my mind. When it comes to ammo used for hunting hogs though....
And I don't own any 20" guns as of now, 16" is the longest I roll with. So I never knew that, but it's good to know for future reference for sure.
Although it could be important to some, velocity isn't an issue to me with training ammo.
Same here. I handload my own training ammo, and it is really mild. But using the RIGHT propellant can make even weak ammo run on a wide variety of gas systems/barrel lengths.
These foreign ammo companies can't seem to figure this out.
MadcapMagician
06-16-10, 18:34
Same here. I handload my own training ammo, and it is really mild. But using the RIGHT propellant can make even weak ammo run on a wide variety of gas systems/barrel lengths.
These foreign ammo companies can't seem to figure this out.
As I understand it per Herr Hackathorn, the Wolf .223 is loaded using powder made for the 5.45 (as the Ruskies don't sell to many domestic .223s). The 5.45 round operates at a much lower pressure, which causes the .223 loadings to be much weaker.
RetreatHell
06-16-10, 18:49
As I understand it per Herr Hackathorn, the Wolf .223 is loaded using powder made for the 5.45 (as the Ruskies don't sell to many domestic .223s). The 5.45 round operates at a much lower pressure, which causes the .223 loadings to be much weaker.
That's interesting. If it's true it would make sense to me.
But ammo and ammo types is something I'm literally just beginning to understand.
I have 2200 rounds through mine including 1500 over a 3 day carbine course. All ammo was Centurion M193 brass cased 55gr except for a few federal 69gr rounds I had. No problems. My buffer isn't marked as an H buffer. I might be an "H," but at this point I can't even remember where it came from.
And, I will add, this setup is fantastic. It is light, fast and has the recoil of a mouse fart. :D
What muzzle break do you have on it?
While we're talking muzzle brakes and the 14.5 BCM mid-lengths, I have a question too.
Is there any major drawback to going with permanently attached brakes (aside from the obvious loss of flexibility)?
I think there are going to be a few surprises when it comes to the midlength 14.5" uppers from BCM. People are going to want them.
I hope you don't mean they are going away.
I think there are going to be a few surprises when it comes to the midlength 14.5" uppers from BCM. People are going to want them.
Do tell...........I've got one, and built 1 from a Sabre and one from DD. This is my favorite configuration.
Do tell...........I've got one, and built 1 from a Sabre and one from DD. This is my favorite configuration.
Gunz and I got to start the T&E on one of the BCM middies yesterday...
https://www.m4carbine.net/showthread.php?t=56626
After an approx. 100 round break in with Centurion M193, I ran my 14.5" middy through a 3-day class during which I shot nearly 1,100 rounds without cleaning. About 1k of that was PMC 55gr. Using an H-buffer I didn't have any issues.
I'm going to zero mine today with some 62 grain Wolf. I'm taking along a C buffer just in case the H has issues.
ejeffreyhorn
07-06-10, 12:09
What muzzle break do you have on it?
I have the pinned A2X.
I didn't read every word of this thread but BCM says run an H buffer and all mil spec pressure ammo will work. If not using mil spec ammo then run a carbine buffer. So to be sure with any ammo, run the carbine buffer. That's what mine has and is digests all kinds of loads. It's a sweet, soft shooter by design, H buffer for practice and matches. But for real work run the carbine buffer, ain't gonna wear the gun out.
I zeroed and ran mine with some 62 grain Wolf last night. 140 rounds total (20 to zero then four Pmags). I am sold. I topped mine with an Eotec XPS and ran it though some very quick and simple drills. 2 rounds in each of 10 2" dots, 10 rounds into one dot, etc. I can't say that I overran the trigger, but it's a new technique to get used to. Typically I would use the recovery from the recoil to stage the trigger and with the zero muzzle-climb of this upper it takes a slightly different technique to run it fast. I'm considering putting one of my Geisselle 2-stage triggers in it but I'm not sure a two-stage is the answer. It may just be a case of getting used to the rifle.
I do think that the XPS is a perfect match for this rifle.
I am a fan, and it's been awhile since I had a gun I was so looking forward to shooting and getting the hang of, and that I see so much potential in.
Good to hear wolf is running OK.
Got any pictures of your rifle up yet rob?
http://i428.photobucket.com/albums/qq10/tacticalyellowvisor/Reviews/Firearms%20and%20Accessories/BCM%20TandEs/DSC_6128.jpg
Powered by vBulletin® Version 4.2.5 Copyright © 2024 vBulletin Solutions, Inc. All rights reserved.