Short Cycling Issues On Mid length BCM Upper

[torquefliteterror]

So if it is a buffer weight what would you guys recommend? Currently I have just the stock carbine weight and spring. I haven't put it on a scale yet but I believe its 3oz. Is there a lighter weight? What about changing to a softer spring? Or maybe a combination of them?

have you lubed the gas rings and greased the rails and locking lugs? I would start there. It could be you just dried out the mild amount of lube they put on it from the factory.

I've seen countless people at the range experiencing the same issue as you , and just about everytime their BCG is dry as a bone.

[USFSFire]

I actually lube the BCG after every trip to the range. I usually use Winchester break free then use lucas gun oil. Or just plain ole CLP.

[cal3gunner]

...

[torquefliteterror]

I actually lube the BCG after every trip to the range. I usually use Winchester break free then use lucas gun oil. Or just plain ole CLP.

have you tried a new batch of ammo or a known good functioning mag? You don't have too many options on buffers since you say you have the standard carbine buffer. they only go up in weight.

[USFSFire]

When I shoot the gun empty the bolt catch catches the BCG at the neck of the bolt just before the carrier itself obviously not where it is supposed to. I run c products, magpul, and colt mags, and since the issue I have shot PMC Bronze and Winchester 5.56.

[USFSFire]

Oh and idk if it makes a difference but its a Full Auto BCG from Bravo Company.

[torquefliteterror]

My friend's gun was shortstroking , he took it apart and found the gas block had melted. He never told me where it came from . (I suspect a cheap chinese import)

The AR is fairly simple as far as mechanical devices go.
take off the handguard, and flash suppressor and remove your gas system. check to make sure nothing silly has occured.

also check your carrier key and your rings. maybe something came loose or melted.

It's just odd for it to work well for 200+ rounds then start failing.... It has to be something easy for you to track down. you just have to do invasive surgery.

[dieselpower]

My friend's gun was shortstroking , he took it apart and found the gas block had melted. He never told me where it came from . (I suspect a cheap chinese import)

The AR is fairly simple as far as mechanical devices go.
take off the handguard, and flash suppressor and remove your gas system. check to make sure nothing silly has occured.

also check your carrier key and your rings. maybe something came loose or melted.

It's just odd for it to work well for 200+ rounds then start failing.... It has to be something easy for you to track down. you just have to do invasive surgery.

there is another thread about these...

[torquefliteterror]

there is another thread about these...

Do you know which vendor is selling them? I know China can produce decent to high quality stuff at times but some of the lesser skilled Chinese manufacturers produce outright crap.

The stuff can look spot on but the choice of materials ruins it.

[SouthCoastTargets]

My BCM middy short-strokes when i use wolf in it, and i think its because i have a cheap POS BCG in it. if i keep it really wet the problem isnt all that bad but does still happen, eats brass ammo just fine, heres a video of it with a slide fire eating through the brass stuff:

My reloads work beautifully in it too, and they are cheaper than wolf

[FeuerFrei]

Rifle's symptoms sounds like it's under gassed. Gas block, gas key, gas tube. Gas leak. Google "ar15 short stroking". BTW warranty is an option? You can always swap upper and lower with a buddy and see if the problem persists.


Sent with 2 cans & a long string.

[MXRider]

How does the rifle run with M855 or M193?

Rifle's symptoms sounds like it's under gassed. Gas block, gas key, gas tube. Gas leak. Google "ar15 short stroking". BTW warranty is an option? You can always swap upper and lower with a buddy and see if the problem persists.


Sent with 2 cans & a long string.

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.

Sent from my PC36100 using Tapatalk 2

[MXRider]

And I'm not trying to defend BCM in any way, it could be an issue with the upper. I'm just giving my experience with the same uppers and state the way BCM designs their weapons.

Sent from my PC36100 using Tapatalk 2

[vintagearms]

I know I just wanted to state I havnt run I to any issues.. I didn't mean it as a disagreement or saying it was untrue or couldn't happen...

I'm just glad I havnt run into that.... (Yet) that being said I only run XM/green tip stuff... Been tempted to try wolf for a little while and save on costs and see how it runs...

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.

[triggatronic]

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.

Sent from my PC36100 using Tapatalk 2

Hmm maybe that's the issue with my friend's Spikes Tac rifle. He shoots PMC bronze and the American Eagle .223 and whatever else he can get for the low. Every now and then he'll get a bad jam on the next round because of short stroking.

I've definitely got to try some of that M855.