AR10 BCG Group Jamming

[sig2009]

Just finished helping a friend build a .308. Wislon Combat Urban Sniper barrel. Aero upper and lower. Alpha BCG. I have never heard of Alpha before. Chamber a round with 3 different brands of factory ammo. Chamber and shoots. Doesn't eject. I have to use a rubber mallet to get the charging handle to extend to eject round. Any thoughts. I think it's this Alpha BCG. I have a BCG from my DPMS I will try this weekend to to see if it works. In the meantime he ordered a Toolcraft .308 BCG. He had a RRA BCG but the carrier is about a half inch longer.

 

[Deleted member 113831]

These might be a stupid questions, but are there any gas rings on the bolt? Or, are they broken? Is the gas tube or gas key blocked?

 

[nope]

It sounds like you have yourself a sweet single shot rifle. I swear I'm not insulting you here, I've just seen it too many times with AR's to not mention it; Do you have the correct length gas tube (long enough)? If so, then go through the gas system checking for gas block alignment, binding, boogers, burrs, and proper sealing all the way through your BCG- sometimes companies try to go the extra mile and seal the gas key only to use too much sealant and goop up the port. Swap the BCG like you're planning to (not a bad idea to check head space with the new bolt before firing) and see how she goes.

 

[TonyTheTiger]

Even with a gas restriction problem it shouldn't take a mallet to remove a fired case. Is the bolt cycling and ripping off the rim or is the whole thing locked up tight?

 

[aSilk_Suit007]

To me, It sounds like it may be under gassed. check you gas block, tube and key on your bolt. Also Im not talking shit but, DPMS....I heard some un-pleasant things. Keep us posted.

 

[BLDTYLRY]

Can you shoot it with the gas turned off? Either it is way overgassed; unlocking/extracting brass before the brass has time to shrink. Or you have a tight chamber. What ammo? Buffer weigh? Is the BCG well lubed?

 

[sig2009]

Even with a gas restriction problem it shouldn't take a mallet to remove a fired case. Is the bolt cycling and ripping off the rim or is the whole thing locked up tight?

After every shot it does not eject and I have to use a rubber mallet to push the charging handle back to eject round.

 

[sig2009]

These might be a stupid questions, but are there any gas rings on the bolt? Or, are they broken? Is the gas tube or gas key blocked?

Will have to check when I see him this weekend.

 

[sig2009]

To me, It sounds like it may be under gassed. check you gas block, tube and key on your bolt. Also Im not talking shit but, DPMS....I heard some un-pleasant things. Keep us posted.

The DPMS BCG I have has a JP bolt.

 

[sig2009]

Can you shoot it with the gas turned off? Either it is way overgassed; unlocking/extracting brass before the brass has time to shrink. Or you have a tight chamber. What ammo? Buffer weigh? Is the BCG well lubed?

Three different types ammo. 168gn Fed GMM. 149gn Federal White box XM80C. Winchester Match 168gn . Yes bolt carrier and bolt well lubed. Buffer is a JP silent capture spring unit.

 

[sig2009]

It sounds like you have yourself a sweet single shot rifle. I swear I'm not insulting you here, I've just seen it too many times with AR's to not mention it; Do you have the correct length gas tube (long enough)? If so, then go through the gas system checking for gas block alignment, binding, boogers, burrs, and proper sealing all the way through your BCG- sometimes companies try to go the extra mile and seal the gas key only to use too much sealant and goop up the port. Swap the BCG like you're planning to (not a bad idea to check head space with the new bolt before firing) and see how she goes.

Yes rifle length gas tube and Wilson Combat low profile medium gas block.

 

[flyer]

You need to have someone look at the bolt while the rifle is shot to see if it moves at all.

Check out the finish in the chamber.

You should carefully inspect the receivers to see if there is any impact damage inside it but it does sound like no gas for some reason.

 

[sig2009]

Just spoke with Wilson Combat and they are leaning towards this Alpha BCG being the culprit. He told me to try the DPMS BCG with the JP bolt I have. He said it should work with the DPMS. If not he says it could be a tight chamber issue with barrel and they would make it right.

 

[davsco]

did you try loading a round and then ejecting it before firing? maybe tight or dirty (albeit new) chamber?

 

[sig2009]

did you try loading a round and then ejecting it before firing? maybe tight or dirty (albeit new) chamber?

No. Trying it tomorrow.

 

[sig2009]

Well it looks like the BCG was bad. Replaced with my DPMS carrier with JP bolt and it shot great!!!!!!!!!!! Those Wilson Combat Super Sniper .308 barrels are great. 6 shots in black after final sight in. 100 yards with Federal 175gn GMM. 1" target dot.

 

[TonyTheTiger]

Does it extract an unfired case properly now?

 

[flyer]

Well if you put the Alpha bolt in the DPMS carrier and it runs, that will show you the Alpha bolt carrier is what is at fault. If it doesn't run, the bolt is bad and the carrier is questionable.

 

[sig2009]

Does it extract an unfired case properly now?

Yes. Works perfectly.