AR 10 cycling issues

[ctafoya]

Had some time to finally go shoot a little today. My M1A ran lake crap for the first time ever. Fail to eject and light primer strikes. Root cause, I didn't clean it last time I shot. Oops. 

Second issue is my new AR 10 build. It would not cycle. Shooting federal gold medal 175's. It was immediately on target at 100 yards with a new scope that has never seen the light of day. But it would not cycle. All new high quality parts, properly lubed. 

I'm guessing I'm over gassed and need a heavier buffer. Anyone have any other issues they have run into with an AR 10 that wasn't a buffer or lube issue? 

[520couse]

Yeah an adjustable gas block solved it.

You can tune the gas to the action.

Is it ejecting the spent case?

[ctafoya]

It's ejecting but not feeding the next round. 

[HyNoon]

Sounds like gas block might be out of alignment a little bit and I would try an adjustment gas block as well, especially if you plan on running a can on it later. 

[firstcoueswas80]

If it's ejecting but not picking up the next round, that sounds like a magazine issue to me.

[Couzer]

Might be the shooter? Just saying. All kidding aside I would say gas block, 520coues good thinking man!

[Crazymonkey]

My hunting buddy  had his doing  the same  thing  . Added a adjustable  gas block and changed the buffer spring rate and buffer weight 

[fatbastard]

Was the rifle in question built or purchased complete or complete upper or lower? Not much to check with the lower except the trigger/hammer. As others have suggested, it may be under gassed because of poor gas block alignment. It may also be over gassed so much that the bolt is bouncing. What length gas system does it run? Is the gas block pinned or set screw? Are the set screws dimpled if not pinned? What recoil system does the gun have( carbine/rifle/fixed/ adjustable), do you happen to know the weight of the buffer?

I found the first one I built to be pretty harsh on recoil but still function properly with a mid length gas and carbine buffer system. I changed the buffer system to A5 configuration and added 3 ounces to the buffer and a braided spring and she is smooth now. A carbine gas/carbine buffer combo REQUIRES an adjustable gas block IMHO. I built mine with an adjustable gas block, got the gas dialed in to lock back on empty and I haven't changed it since. Even monkeying with the recoil system afterwards has not required any adjustment to gas.

[Hoss50]

Won't cycle could be different things. 

What exactly is it doing? 

[MULEPACKHUNTER]

Mag fit, undergassed. Where did it toss the brass? behind you? 90 degrees to the right is optimum rule, forward toss is overgassed

I see alot of gas holes in barrels off to the block. After shooting pull it apart and be sure the block didnt move and look at the hole in the barrel, most times I see a figure eight shape from the gas hitting the barrel where its out of alignment.

[ctafoya]

I can't recall where the cases ended up. It will fire and cycle, but not load. It is an 18-inch barrel. Set screw gas block, nonadjustable. The buffer is 5.6 ounces. Rifle length gas system.

[ctafoya]

I think I'm gonna order these and give it another try.

[ctafoya]

I also ordered a Geissele braided buffer spring. Hopefully that does the trick. 

[Couzer]

45 minutes ago, ctafoya said:

I also ordered a Geissele braided buffer spring. Hopefully that does the trick. 

Sexy

[firstcoueswas80]

That thing is good looking...

 

However, have you tried other/new/different mags?

 

Sounds like it's doing every step accept picking up the brass from the magazine.