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View Full Version : Having Problems with my BCM AR-15 and PMC 223-UPDATE!


DavidRSA
10-28-2010, 4:09 PM
I have used thousands of rounds of PMC in my Smith & Wesson AR-15 without any problems whatsoever.

I have a brand new BCM complete upper. I fired it for the first time today. Started out using PMC .223 and one of every 10 rounds or so failed to feed correctly. The rounds had scratches and dents as seen on the picture.

I then switched to Federal XM193 556 and didn't have one issue.

Any ideas what the cause could be? I mean, BCM is a good manufacturer and PMC has a good reputation.

http://i945.photobucket.com/albums/ad299/DavidRSA/d2edbcb3.jpg

Trendkill
10-28-2010, 4:12 PM
FWIW....mine did that for a while too.....then it went away.


Lube it up real good and it will break in.

If not.....email the guys at BCM and they will take care of you , they really stand by their product.

sleepercar
10-29-2010, 8:01 AM
1 in 10 random? First? Last?

DavidRSA
10-29-2010, 9:14 AM
Totally random. But never was the first or last..

r6raff
10-29-2010, 9:33 AM
Is the BCM on the same lower as the SW was? Have you tried any other ammo through it? Sounds like maybe a pressure related issue, or your buffer/spring combo is incorrect for you build. I would try a few different ammo types with a mix of 556 and 223 and see if this issue is consitent with 223 alone. Good luck:thumbsup:

ChrisTKHarris
10-29-2010, 9:47 AM
That happened to my DD upper with PMC and it even jammed a couple of times. Now with about 700 rounds through it it's not doing it anymore.

r6raff
10-29-2010, 9:53 AM
Sounds like its a semi common :confused: break in issue. I have personally never seen it but this is good info to store away.

how many others have had similar issues that end up going away. If I had this happening to my weapon I dont think I would have kept shooting to see if it went away, I would have assumed something was malfuntioning.

What is it that causes this and why does it end up going away?

I am curious by nature, I apologize

bjl333
10-29-2010, 9:56 AM
You don't have a problem, your PMC ammo is the problem. The 223 is not fully cycling the bolt and its short stroking into the ammo. Keep using 5.56 ammo and you should be fine.

Sgt Seahorse
10-29-2010, 10:06 AM
You don't have a problem, your PMC ammo is the problem. The 223 is not fully cycling the bolt and its short stroking into the ammo. Keep using 5.56 ammo and you should be fine.

+1

people always try to tell me that .223 is the same thing as 5.56. They differ in about ~7000 psi in chamber pressure. So stick with the 5.56 and you should be fine.

DavidRSA
10-29-2010, 10:06 AM
Is the BCM on the same lower as the SW was? Have you tried any other ammo through it?

Yes the same lower, the one which came with my S&W MP-15T
Only tried the 2 types of ammo, the Federal XM193 and PMC 223

Will be back at the range this weekend, will try some Prvi 62gr match and try the pmc again.

Thanks for the help!

r6raff
10-29-2010, 10:10 AM
You don't have a problem, your PMC ammo is the problem. The 223 is not fully cycling the bolt and its short stroking into the ammo. Keep using 5.56 ammo and you should be fine.

What I was thinking BJ, im guessing any 556 he gets will probably cycle fine, couldnt he also adjust his buffer or spring to accomodate the lower pressure of 223

bender152
10-29-2010, 10:18 AM
Ran into a similar problem with an upper I was troubleshooting. In my case, the upper would not feed Wolf.

What I found was that the "teeth" of the barrel extension were very sharp. So the rounds were being fed, but the tips would get caught up in these teeth. The round would then jam.

If I fed the upper M855 ammo, it fed just fine.

From looking at your pics, it looks like the round is getting caught somewhere, hence the marks on the neck (right two rounds in your pick). The round gets stuck and the BCG has no where to go, so it rides up on the round, causing the larger dents in the brass.

I'm no expert, that's just my guess.

thehummerguy
10-29-2010, 10:35 AM
I have had same issues with my BCM's, Never had this issue till I started using Full Auto BCG's as sold by BCM, the AR-15 version that is milled off on the rear of the BCG group is lighter, the FA BCG is heavier, thus the Short stroking, the 5.56mm loads that are Mil Spec should work fine, but lighter
loads like .223 and Wolf ammo that is notoriously under powered will short stroke the BCM guns.
BCM guns are made to Mil Spec standard...Not one of my AR's with the AR BCG's have issues, only the guns with FA BCG, But only with Wolf type ammo.

r6raff
10-29-2010, 12:05 PM
I have a bcm16"middy with a FA bcg, I havent had this issue running a h2 buffer. My BCM has eaten up hundreds of WallyWorld 223, PMC 223, hornaday 223 and thousands of xm193. I have put maybe 100 or so Tula 223 steel case rounds through the barrel with out a hiccup. Maybe try a different combo of buffer and spring?

Mute
10-29-2010, 12:30 PM
Is your BCM a mid-length and the S&W a carbine length? PMCs are known to be somewhat under-powered, so the BCM might just not be getting enough gas to completely cycle.

Trendkill
10-29-2010, 12:39 PM
I think its magazine related or a break-in issue.

Theres no freakin reason his rifle shouldnt run PMC.

DavidRSA
10-29-2010, 12:40 PM
Is your BCM a mid-length and the S&W a carbine length? PMCs are known to be somewhat under-powered, so the BCM might just not be getting enough gas to completely cycle.

No, both are carbine length. I am thinking its probably a combination of what previous posters said about the FA BCG, and also the fact that the upper had never been fired before, so perhaps some breaking in is still happening. Will see this weekend.

Josh3239
10-29-2010, 3:13 PM
PMC has a good reputation and Rosie O'Donnell has a slight weight problem. Hate to break it to you but PMC has some of the lowest QC. Bottom line is it is junk and it was short stroking in your rifle. XM193 is military reject (aka junk), but still full power 5.56 and that is why the problem went away, it was actually powerful enough to cycle your rifle. Stick to full power 5.56mm and I would recommend against ammo that the military has rejected. Yes there is a small break in and lubing up will certainly help, but if the rifle isn't getting enough gas then it isn't getting enough gas and different gas system, magazine, or carrier isn't going to fix that.

Cyc Wid It
10-29-2010, 3:26 PM
PMC has a good reputation and Rosie O'Donnell has a slight weight problem.

So by this analogy, PMC has a really really really good reputation :p

Josh3239
10-29-2010, 3:34 PM
:kest: Fair enough. Even so, from what I've seen PMC makes the top 3 for both most KBs in ARs and top 2 for most ammo caused stoppages.

sirnonz
10-29-2010, 3:48 PM
maybe it needs the supplied o-ring gasket for the bcm carrier group? i have a extra one if you want to try it, never needed it for mine but it did come with one.

DavidRSA
10-29-2010, 4:25 PM
maybe it needs the supplied o-ring gasket for the bcm carrier group? i have a extra one if you want to try it, never needed it for mine but it did come with one.

Thanks...I still have mine...that is to help the extractor I think...

DavidRSA
10-29-2010, 4:29 PM
One more thing...dont know if this has anything to do with my problem...when I was cleaning the BCG afterwards, I noticed the bolt gas rings on my BCM were "looser" than the ones on my Smith. Can this cause the short stroking problem?

Trendkill
10-29-2010, 4:32 PM
I want my SHTF rifle to run whatever S*** is available during a SHTF scenario.

If PMC is the only S*** I can find during the zombie apocalypse , I'll be damned if I dont want my rifle to run the stuff. I want it to run everything....

Trendkill
10-29-2010, 4:33 PM
One more thing...dont know if this has anything to do with my problem...when I was cleaning the BCG afterwards, I noticed the bolt gas rings on my BCM were "looser" than the ones on my Smith. Can this cause the short stroking problem?

Nah...they should spin around pretty freely.

supersonic
10-29-2010, 4:36 PM
XM193 is military reject (aka junk)

I just don't see how any U.S.-approved ammunition maker (military contractor/commercial manufacturer - both of which Federal is) could possibly stay in business by allowing any ammo to reach the shelves in less-than acceptable condition. Even PMC, which may or may not have the best QC, still must maintain a certain level of approval. Technically speaking, .223-marked ammo is for .223-chambered bolt action guns. 5.56 is for 5.56mm-chambered 'military-type' S/A rifles, thus are loaded to higher pressures to cycle the action & improve the terminal ballistics. There's not so much of a difference that .223 won't work in an AR-15, but -as shown here - there will be some hiccups once in a while (more so with a brand-new gun designed specifically for 5.56). But "reject" "junk" XM193? Aside from the possibility that it may have not passed military-specs for bullet/primer sealant/case tarnish, please explain what - exactly - makes this ammunition junk? Does it not go 'bang?' Does it not hit the target? Does it regularly cause malfunctions or catastrophic failures in rifles? Inquiring minds want to know!

Josh3239
10-29-2010, 5:20 PM
I just don't see how any U.S.-approved ammunition maker (military contractor/commercial manufacturer - both of which Federal is) could possibly stay in business by allowing any ammo to reach the shelves in less-than acceptable condition. Even PMC, which may or may not have the best QC, still must maintain a certain level of approval. Technically speaking, .223-marked ammo is for .223-chambered bolt action guns. 5.56 is for 5.56mm-chambered 'military-type' S/A rifles, thus are loaded to higher pressures to cycle the action & improve the terminal ballistics. There's not so much of a difference that .223 won't work in an AR-15, but -as shown here - there will be some hiccups once in a while (more so with a brand-new gun designed specifically for 5.56). But "reject" "junk" XM193? Aside from the possibility that it may have not passed military-specs for bullet/primer sealant/case tarnish, please explain what - exactly - makes this ammunition junk? Does it not go 'bang?' Does it not hit the target? Does it regularly cause malfunctions or catastrophic failures in rifles? Inquiring minds want to know!

The military will reject ammo for any number of reasons, some as minor as little dents that don't make a difference, sure I'll admit that. However, there have been more than enough issues with XM193 to make me want to avoid it. Do you know why that run was rejected? I sure don't, and I don't want to guinea pig it. Why? Because despite the small chance, I don't want to be the unlucky SOB that fires of a squib or a round with no flash hole. XM193 (plus PMC and unknown reloads) seem to be the biggest problem causers for ARs ammo wise. I don't know if you follow the kabooms in ARs, but most of them have been caused by XM193. Last year there was a pretty bad batch that was particularly noted on AR15.com and on M4Carbine.net, Lightfighter holds XM in very low regard. Would you not argue with me that on the list of ammo that causes problems, that XM193 isn't high up there? How about for KBs? I am not saying it happens often, I am not saying don't use it, but when it happens (not often but it does nonetheless) and it seems to usually be the same manufacturer, is that not an indication of quality?

I want my SHTF rifle to run whatever S*** is available during a SHTF scenario.

If PMC is the only S*** I can find during the zombie apocalypse , I'll be damned if I dont want my rifle to run the stuff. I want it to run everything....

You want to run everything huh? Ammunition plays a HUGE factor in reliability, probably second to magazines. What's next, you want a platform that has never ever had a bad magazine made for it so you can pick it up in a SHTF scenario without having to function test it? If you want a rifle that won't stop running, one of the first things you should be looking at is good ammo.

If you shoot bad ammo and FUBAR your rifle, your rifle won't be a very good self defense weapon, in fact it might even hurt or kill you. Like gun (parts) or magazines, ammo is not all made equally and the quality is not the same exact thing everytime. You may get a round with no powder, too much powder, too little powder, the wrong powder, no flash hole, incorrectly installed primer, etc, etc. Yes, this can happen with any manufacturer, but just like you parts or your magazines. But we aren't talking about elimenating the problem (that is impossible) we are talking about minimizing it.

Think about it, why do carbine classes generally have rules, if not, recommendations for ammo usage? It isn't because they want their students to frequently stop shooting and trouble shoot their rifles. Why does the military reject ammo from major to minor reasons? Probably do give the troops the best chance of living they can. You think police officers just close their eyes and pick a random box of ammo of the shelf or do they choose the one that has proved reliable and effective enough to keep them alive in a shootout?

You can only make your rifle so reliable, but in the end you have to look at the ammo your shooting and the magazines your running. If your ammo isn't giving your rifle enough gas, it doesn't matter what rifle you are running, what upgrades you've put in, what gas system you have, what platform you have, what nation that ammo was made in or what cool new magazine your using, if the rifle isn't getting enough gas, she won't cycle. If you fire off a round immediately after a squib, I hope you have a rifle built like a brick ****house. When rifles KB most of them are not made to keep shooting, they are made to protect the firer from the rifle turning into a grenade.

Trendkill
10-29-2010, 5:30 PM
You blew my statement waaaayyyy out of proportion.

I dont want a finicky rifle.....i want it to run whatever is available without having little hiccups here and there. Does that mean I want to feed it a steady diet of crap ammo all the time..??? No. But its worth trying a little of everything (barring Umarex and gunshow reloads) at least a little to know your rig aint picky.

I use almost exclusively M855 in my rifles.....but I have also tried a little of everything else too to know its not picky.

jak77
10-29-2010, 5:49 PM
I feed my BCM a steady diet of **** and it has never caused me problems. Wolf, brown bear, pmc, tula all work fine. Only used m855 and 193 a few times. Those worked fine too. I'm too cheap to run expensive ammo through my rifle. That's why I went bcm, because I knew it would eat anything. If this still happens I would call up bcm, they will probably replace the upper for you. They are great people who stand behind their products 100%.

pipboy
10-29-2010, 7:05 PM
I've experienced a similar issue before. FWIW, in my case, new magazines cleared it right up.

supersonic
10-29-2010, 7:07 PM
The military will reject ammo for any number of reasons, some as minor as little dents that don't make a difference, sure I'll admit that. However, there have been more than enough issues with XM193 to make me want to avoid it. Do you know why that run was rejected? I sure don't, and I don't want to guinea pig it. Why? Because despite the small chance, I don't want to be the unlucky SOB that fires of a squib or a round with no flash hole. XM193 (plus PMC and unknown reloads) seem to be the biggest problem causers for ARs ammo wise. I don't know if you follow the kabooms in ARs, but most of them have been caused by XM193. Last year there was a pretty bad batch that was particularly noted on AR15.com and on M4Carbine.net, Lightfighter holds XM in very low regard. Would you not argue with me that on the list of ammo that causes problems, that XM193 isn't high up there? How about for KBs? I am not saying it happens often, I am not saying don't use it, but when it happens (not often but it does nonetheless) and it seems to usually be the same manufacturer, is that not an indication of quality?


So there have been actual documented events in which 193 was found to have no flash holes? That's pretty major! I've run thousands upon thousands of 193 in many different AR's and have never had one problem. Which is the 'gold standard' 100% reliable, 100% CQ, fool-proof 5.56 in your estimation?:confused:

themailman
10-29-2010, 7:57 PM
ive seen alot of ppl have this problem with .223 ammo and not 5.56. just something to think about.

Cali4nia_AR
10-30-2010, 12:30 AM
Sorry to hear about your probem. My AR loves PMC. A friend of mine had feeding problems and switched to 556, Problem Gone. Good Luck

Plebius15
10-30-2010, 12:36 AM
I've fired several hundred rounds of PMC through my SPR that has a BCM upper receiver and a BCM FA BCG without a single malfunction.

C_1
10-30-2010, 10:12 AM
I have a 16" mid-length BCM upper, with auto BCG and H buffer; it eats anything and everything (I shoot a lot of "Wolf" ammo). I had a buddy who had the same problem; his ammo looked just like yours. I oiled his BCG and whatnot up real good, then it ran fine. YMMV. But usually its ammo or mag related. Sometimes its the BCG, buffer and spring combo. Worst case scenario is that there is a gas system leak or the gas port hole is the wrong size. I doubt it though but its a possibility. Run her wet with new/different mags and see what happens..

DavidRSA
10-31-2010, 6:54 PM
Just did a full day of carbine class, went through about 300 rounds. Had the same problem with 5.56, as well as 223. Sometimes I could go though 3 of more magazines without a problem, and sometimes I would have it occur one or twice with each magazine. So it cant be the ammo.

I did have some work done on the gun - installing a DD rail which entailed removing with barrel and FSB. Perhaps during this process something went wrong. It does seem likely that something is wrong with the gas system, would most of you agree?

evolixsurf
10-31-2010, 7:19 PM
try different magazines. make sure you have good ones not the stock green follower garbage. bushmaster and magpul have some great mags... Any can be defective though. Your problem will likely go away after break in, but the mags likely make it worse now...

C_1
10-31-2010, 7:57 PM
Just did a full day of carbine class, went through about 300 rounds. Had the same problem with 5.56, as well as 223. Sometimes I could go though 3 of more magazines without a problem, and sometimes I would have it occur one or twice with each magazine. So it cant be the ammo.

I did have some work done on the gun - installing a DD rail which entailed removing with barrel and FSB. Perhaps during this process something went wrong. It does seem likely that something is wrong with the gas system, would most of you agree?

That could be it, see my post above. Perhaps theres a gas leak because something is not tight/right when the DD rail was installed.

Artsville
11-01-2010, 11:55 AM
my BCM loves PMC.......never had a failure....

r6raff
11-01-2010, 12:56 PM
I did have some work done on the gun - installing a DD rail which entailed removing with barrel and FSB. Perhaps during this process something went wrong. It does seem likely that something is wrong with the gas system, would most of you agree?

Was the work done yourself, gunsmith or done by BCM? I was under the assumption that you received the complete upper with handguard from BCM and slapped it on and then had this issue. Like others have said, sounds like a gas leak, and most likely the cause from not correctly reinstalling or positioning the gas tube. If it was done by someone else, i would take it back and have them look at it asap. If it was done by you, I would strip it down and redo it making sure everything is squared away.

Mute
11-01-2010, 1:11 PM
I thought it sounded like a gas issue when you first described the problem.

sfonelson
11-01-2010, 1:44 PM
OP, what kind of mags were you using? I had a similar problem running blocked 10/20 mags. See this thread:

http://www.calguns.net/calgunforum/showthread.php?t=354495

I ran a couple hundred rounds through some 10 round C-Product mags and not a single issue.

ChrisTKHarris
11-01-2010, 3:49 PM
OP, what kind of mags were you using? I had a similar problem running blocked 10/20 mags. See this thread:

http://www.calguns.net/calgunforum/showthread.php?t=354495

I ran a couple hundred rounds through some 10 round C-Product mags and not a single issue.

Yeah a 10/30 P-Mag or dedicated 10-rounder tends to fix any feeding problems.

DavidRSA
11-01-2010, 4:01 PM
OP, what kind of mags were you using? I had a similar problem running blocked 10/20 mags. See this thread:

http://www.calguns.net/calgunforum/showthread.php?t=354495

I ran a couple hundred rounds through some 10 round C-Product mags and not a single issue.

I have been using pmag 10/20's. But these worked flawlessly though the same lower when it had the original S&W upper.

In any event, BCM sent me a return label so they can do an inspection. Will post the results as soon as I know...l.

sfonelson
11-01-2010, 4:04 PM
Don't return it yet. I will bet you money that it's your 10/20 mags.

In my issue, these mags worked fine in my other rifle. It was the same style lower with a GG&G upper, the issue only started happening with the BCM.

I'm pretty confident that if you go buy a 10 round C-products mag you won't have an issue. That way you don't have to deal with returning the upper, then having it shipped back to you.

I have been using pmag 10/20's. But these worked flawlessly though the same lower when it had the original S&W upper.

In any event, BCM sent me a return label so they can do an inspection. Will post the results as soon as I know...l.

DavidRSA
11-01-2010, 4:18 PM
Don't return it yet. I will bet you money that it's your 10/20 mags.

In my issue, these mags worked fine in my other rifle. It was the same style lower with a GG&G upper, the issue only started happening with the BCM.

I'm pretty confident that if you go buy a 10 round C-products mag you won't have an issue. That way you don't have to deal with returning the upper, then having it shipped back to you.

Thing is, these mags worked flawlessly through thousands of rounds with my smith upper. The way I think on this, there is no reason why the BCM shouldn't either. I dont want to have to buy new mags...I have at least 10 pmags..

Yours was an interesting thread though... described the same issue to a "T"

DavidRSA
11-01-2010, 9:34 PM
Well check out the pics below. It happens with snap caps too!

Always on the 7th or 8th round. Only happens with pmags. And I cant say with certainly it is not just blocked pmag 10/20's. It happens with every one of my pmags, which I purchased at the beginning of the year. And again it never happened with my S&W upper using the same lower and same pmags.

Looks like there is an issue with the BCM/pmag combo, or at least in my case and in sfonelson's.

I'll discuss with BCM tomorrow.... since it is not a problem with other BCM's and pmags, I dont want it to be a problem with mine!!

http://i945.photobucket.com/albums/ad299/DavidRSA/9fe5fddd.jpg
http://i945.photobucket.com/albums/ad299/DavidRSA/31e7723c.jpg

Solidsnake87
11-02-2010, 12:30 AM
I think its magazine related or a break-in issue.

Theres no freakin reason his rifle shouldnt run PMC.

I just bought a BCM upper and it runs on PMC without any issues. PMC is pretty good stuff, so there should be no reason your upper is doing that. However, regardless how well a company QC its products there is bound to be one flaw sooner or later.

Take a flashlight and inspect your chamber and feed ramps. Are they deformed? Are there are burrs that might cause a feeding round to get caught, and subsequently get dented?

With that said, the dents in your cases do not mirror the deformation caused by under pressure rounds. I checked my sierra reloading manual just to be sure.

I think it might be magazine related. Swap to diff mags and see if that helps.

EDIT: I saw your snap cap pics, as I thought, the dents are caused by feeding issues--not under pressure rounds. I wonder if you magazine is not sitting high enough to allow rounds to contact the bolt with enough surface area to reliably feed. This could possibly be a lower receiver issue if the mag well release were not positioned properly. :eek: There might be an easy solution though. When you rack your AR, do you let the charging handle go after you pull all the way back? Riding it forward has always caused jams in my guns that are JUST like those pictures.

sfonelson
11-02-2010, 8:42 AM
This was my exact issue. When using my 10/20 Pmags, I could definitely see how the end of the cartridge was angled down, so when the bolt came back forward to load a new round, it wouldn't catch it right.

My 10/30 works flawlessly along with my 10 round c-product mags. The tension in the working mags is noticeably different and stronger.

OP: I know it sucks since you have several PMags, but this is the nature of the hobby. Looks like you may have to invest in some different mags. At least try one 10 rounder. Probably cheaper then your time spent having to be without an upper for however long it takes BCM to check it out.

On a side note, I did send my 10/20 Pmags back to Ty at Midwest PX for a block update. I haven't had a chance to try them out yet.



EDIT: I saw your snap cap pics, as I thought, the dents are caused by feeding issues--not under pressure rounds. I wonder if you magazine is not sitting high enough to allow rounds to contact the bolt with enough surface area to reliably feed. This could possibly be a lower receiver issue if the mag well release were not positioned properly. :eek: There might be an easy solution though. When you rack your AR, do you let the charging handle go after you pull all the way back? Riding it forward has always caused jams in my guns that are JUST like those pictures.

THT
11-02-2010, 9:14 AM
Out of curiosity, have you tried shooting the S&W upper again? I suspect your upper is short stroking.

DavidRSA
11-02-2010, 9:29 AM
Out of curiosity, have you tried shooting the S&W upper again? I suspect your upper is short stroking.

I thought so at first as well, but then it wouldn't happen with snap caps. Plus it doesn't happen with other brand magazines.

By the way, someone else who was having the exact same issue and solved his problem in a way by ordering the stubby 10 rounder pmags from you. So I placed an order with you for 2 of them last night. Will see if that solves the issue

bjl333
11-02-2010, 9:52 AM
I thought so at first as well, but then it wouldn't happen with snap caps. Plus it doesn't happen with other brand magazines.

By the way, someone else who was having the exact same issue an I am solved his problem in a way by ordering the stubby 10 rounder pmags from you. So I placed an order with you for 2 of them last night. Will see if that solves the issue

Good luck !!! I hope that'll solve your problems.

captbilly
11-02-2010, 10:27 AM
+1

people always try to tell me that .223 is the same thing as 5.56. They differ in about ~7000 psi in chamber pressure. So stick with the 5.56 and you should be fine.

I think this is a case of a bit of misinterpretation of the data. The way I understand it, the 5.56 specification requires a different method of measuring the pressure. That chamber pressure measuring method would be expected to give higher readings, even with the same loading. I would make the analogy of measuring outside air temperature in the sun or in the shade. Both temperatures are correct, but the temperature read in the sun would obviously be much higher, even though it is theoretically measuring the temperature of the same thing.

.308 vs. 7.62 x 51 NATO is a similar story. The spec. for measuring pressure for .308 is different than how NATO specifies the pressure should be measured, leading to one of the two appearing to run much higher pressure but in reality it is just the measurement location and measurement device that is different.