FTF

[MONTANA308]

Ok so I bought a BRO complete upper slap it on my lower won't hold any sort of group with any type of ammo I'm talking couldn't hit a barn side twice kinda group. So they send me a new barrel same length it's a 18in bull barrel first one was a mid length and now this one is a rifle length. I finally get it all put together tonight and it will fire one round and then FTF every time.

I have the BCG well lubed and everything seems to be working on the first round perfect ejection brass would land about 3-4 ft at the 3oclock. Just won't pick up anther round.

Any info would be great guys!!

[DNP]

Load one round. Fire, and see if it locks open. It sounds like the bolt isn't fully cycling. I'm still a newb...under gassed? Buffer too heavy? Just thoughts.

Edited June 6, 2013 by DNP

[EasyEJL]

and what magazine are you using?

[MONTANA308]

Ya thats what ill try tonight running clint's hss buffer and spring. Worked great on mid lenght. I was using a colt mag that go around

[DNP]

There was a good thread going in here about the location of the gas block too. Was it already installed or did you put it on? Would be good to check. These guys could say more. They say there should be a gap about two business cards thick from the shoulder to the gas block. The buffer or the GB is likely your issue, though I've heard talk of incorrect holes in barrels before too. So many little things that all have to work together.

[MONTANA308]

Waiting on my SI NIB BCG I was borrowing one out of my wife's work carbine thoughts i better hold off on any more testing with her BCG. In case i F something up. mine should be here today or tomorrow. Then I'll continue the testing I dicked with the gas block position so we will see here in a day or two. Thanks for the help

[survivalshop]

Not a good idea , running another used Bolt, with out checking head space first .

 

Try a different mag..

 

Check as said above with the one round in the mag. & see if the BCG locks open. This alone will tell you which direction to look , to clear the FTF up.

[MONTANA308]

Ok got my new BCG today put it in rifle with a different mag. Fired one round bolt lockd back. Thought good so I try the test again. Bolt wouldn't lock back tried anther different mag same thing bolt will not lock back when fired. Going to try moving GB forward a little more. I'm running a HSS buffer and spring from Clint.

[DNP]

Do you have another spring and buffer to try? What ammo? Those are other spots to look.

[DNP]

Making any progress? Need anything to help out?

[MONTANA308]

No DNP been so busy trying to get my calves branded i havent picked up the rifle. Im shooting winchester ranger ammo. Dont have any other spring or buffer. I tried moving gas block around and had no luck made it worse but never better. Need to up grade my allen wrench to i may not be getting block screws tight enough. thanks for all your help and suggestions. Ill keep ya posted its suppose to rain may get some time to work on it.

[Magwa]

18 inch barrel rifle length gas system the dwell time is probably to short with that buffer you will have to try different combos of buffers and or springs undergassed is most likely the culprit .. IMO