Short Cycling Issues On Mid length BCM Upper

[MXRider]

Midlength gas with a carbine buffer system should run fine with Wolf. Its when you run a rifle length buffer system like I do that sometimes has issues with Wolf.

Not always. It depends on the size of the gas port on the barrel. BCM mid length with weak ammo shortstroking is a know phenomenon for some.

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[vintagearms]

Not always. It depends on the size of the gas port on the barrel. BCM mid length with weak ammo shortstroking is a know phenomenon for some.

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True, just not in all cases. I run a BCM 14.5" upper with BCM FA BCG.

[MXRider]

Both of mine are 16" with their BCG, H buffer and carbine spring.

The one that chokes on wolf is pretty new though, only about 500 rounds through it.

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[torquefliteterror]

You summed it up pretty good right here

The BCM is ported for full pressure ammo.... If one intends on running low pressure ammo like the russian stuff, they need to port it larger.....

I know there is no real standard in the Ar world cause I have assembled a ton of rifles and pistol uppers and have found quite a large range of port sizes....

It just depends on what the company chooses when they place their order for barrels.

How does the rifle run with M855 or M193?



I wouldn't consider it under gassed if it is short stroking with weak ammo. BCM uses gas port sizes for NATO spec 5.56 ammo like M855 and it is well known that some of rifles don't like weaker ammo.

I have 2 BCM mid length rifles and with both they sometimes won't lock the bolt to the rear with cheaper ammo like pmc bronze and I have had short stroking issues with wolf in one of them.

This is a trade off of having a gas port that is designed for NATO ammo, and why some other commercial rifles run larger ports so they will run on weak ammo. It is up to the buyer to decide what they want in a rifle prior to purchase.

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[sd_shooter]

All this talk of gas ports brings up an interesting point. OP, what type of barrel did you get? I got the 'standard' BCM HBAR, not the BFH. Wolf has been fine for me.

[USFSFire]

Shoot honestly I have ran wolf ammo through the rifle as well as other cheap stuff. My incident happened while I was shooting about 150 rounds of ammo at a decent pace, I got about to round 100 when I had a failure to feed and its been single shot ever since. Before that I had around 200 rounds through it with no problems and after the issue I have had around 30 ,mostly single shot, sometimes I'll be lucky and get 3-4 off before it decides to throw a fit again. The rifle has been great with all ammo so honestly I would rule out that and mags, I clean the rifle religiously at all the right points which I compared with the diagram above... so I'd like to rule out that one as well. But I did come here looking for some good advice and I thank you all for participating to help me out. I tried to look on BCM's website but it seems they are down. However I looked on their other website and it says that they use a H buffer in the recce16 model, the one that I ordered from them has no markings anyone know what this means? Also I am going to take off the gas tube today and see what I find.

[USFSFire]

Shoot honestly I have ran wolf ammo through the rifle as well as other cheap stuff. My incident happened while I was shooting about 150 rounds of ammo at a decent pace, I got about to round 100 when I had a failure to feed and its been single shot ever since. Before that I had around 200 rounds through it with no problems and after the issue I have had around 30 ,mostly single shot, sometimes I'll be lucky and get 3-4 off before it decides to throw a fit again. The rifle has been great with all ammo so honestly I would rule out that and mags, I clean the rifle religiously at all the right points which I compared with the diagram above... so I'd like to rule out that one as well. But I did come here looking for some good advice and I thank you all for participating to help me out. I tried to look on BCM's website but it seems they are down. However I looked on their other website and it says that they use a H buffer in the recce16 model, the one that I ordered from them has no markings anyone know what this means? Also I am going to take off the gas tube today and see what I find.

[MXRider]

So it is now a bolt action only? Check your gas key on top of the bolt carrier, make sure it isn't loose. Check and make sure the gas rings are not damaged, also make sure the gas tube isn't obstructed. If you have a known good BCG or know someone who has one, swap it out and see if that does anything for you. If that doesn't work you could have an armorer look at it and see what the issue is as it could be with the front sight post/gas block or the port itself. And if you can't get it resolved it might have to go back to BCM, their warranty service is very good, but you will be without the rifle for a month or so.

If the buffer doesn't have any marking then it is a carbine buffer and is lighter than an H buffer.

[sd_shooter]

Originally you said:

Originally Posted by USFSFire
I have and always lube all the parts on the chart and I also shoot every time with the rifle firm against my shoulder. The ammo I run 90% of the time in my gun is PMC X-tac or Winchester 5.56 FRANGIBLE rounds.

Then someone suggested:

How does the rifle run with M855 or M193?

Even later you wrote:

Shoot honestly I have ran wolf ammo through the rifle as well as other cheap stuff. My incident happened while I was shooting about 150 rounds of ammo at a decent pace, I got about to round 100 when I had a failure to feed and its been single shot ever since. Before that I had around 200 rounds through it with no problems and after the issue I have had around 30 ,mostly single shot, sometimes I'll be lucky and get 3-4 off before it decides to throw a fit again. The rifle has been great with all ammo so honestly I would rule out that and mags, ...

So, the Winchester was frangible? Aren't those something like 45grain? I would not be surprised if they gave you trouble. And I wouldn't rule out the ammo until you've run some M855 or M193 as suggested.

Example of crappy Frangible ammo:

[USFSFire]

Yes sadly it is, gas key is firmly in place, gas rings are good, gas tube is a pain to get off already broke a allen wrench trying to get the gas block off. Maybe I am wrong but if I have shot steel rounds, .223 remington,and 5.56 x-tac(mostly), with no issues for several hundred rounds I would think that it would fire a 62gr m855. I've fired a lesser quality ammo and have had no issues until recently I think that if I fire a higher quality round I'll still have the same issues. I'm not excluding it though. Yea the frangible were 45 grain. During the time the error occurred I was firing federal .223

[MXRider]

Something failed if the rifle is now a bolt action, it's not ammo related. I think you need to have someone with experience with the AR platform look it over. Find an armorer in your area or send it back to BCM.

[USFSFire]

Also just to be clear the weapon is not jamming the bolt does not travel rearward enough for the round to be pushed up.

[USFSFire]

Do you know of any guys you would recommend to look it over?

[MXRider]

Also just to be clear the weapon is not jamming the bolt does not travel rearward enough for the round to be pushed up.

Wait, so the gas system is pushing the bolt back, but not far enough to chamber the next round? What specific ammo is causing this RIGHT NOW?

Also, try known quality ammo like lake city M855 and report back.

Is this a factory rifle? Or was it something you built with a BCM upper?
What mags are you using?
What specific buffer and spring are you using? How long is the spring?

[MXRider]

Do you know of any guys you would recommend to look it over?

No, I'm sure some socal members will though.