Gas Block Problem?

[UncleDano]

I know most of you are bolt gun guys, but maybe a few of you may have some suggestions for a fix. I have a AR10 in 6.5 CM that will not lock the bolt open on last shot. Wilson Combat adjustable gas block is full open.

Aero Precision M5 Upper & Lower
Wilson Combat Match Grade Tactical Hunter 18" SS Fluted Barrel
Wilson Combat nickel/boron BCG
Wilson Combat adjustable gas block & rifle length tube
VG6 Precision Gamma muzzle brake
3.8 oz. buffer, carbine spring

Ammo: Norma Whitetail 140gr. SP 2756 fps.

 

[belldar]

Try a different magazine

 

[xsn10s]

First manually pull the bolt back to see if it will lock back with the mags in question. Then I'd try lowering the gas. Or try different ammo.

 

[xsn10s]

You might call Wilson and ask them about your gas tube combined with buffer and buffer spring combo.

 

[UncleDano]

Pulling back on charging handle does lock it open. Not sure that LOWERING the gas would help. Will try different ammo when I can find it.
Waiting to hear back from Wilson Combat.

 

[xsn10s]

Well if you don't want to try then I don't know why you'd ask lol.

 

[xsn10s]

You have the gas block wide open so it's either over power the mag catch or not coming back far enough. Sounds like you could be ramming the bolt back so fast that the follower doesn't have a chance to catch the bolt. Bolt comes back hard and bounces forward. YMMV

 

[UncleDano]

You have the gas block wide open so it's either over power the mag catch or not coming back far enough. Sounds like you could be ramming the bolt back so fast that the follower doesn't have a chance to catch the bolt. Bolt comes back hard and bounces forward. YMMV

I started with the gas block at its lowest setting, putting one round in the mag. When the bolt did not lock open, I opened the gas block another increment. Kept doing this until it was fully open and still no bolt locking back.

 

[xsn10s]

Okay then I'd call Wilson.

 

[UncleDano]

You have the gas block wide open so it's either over power the mag catch or not coming back far enough. Sounds like you could be ramming the bolt back so fast that the follower doesn't have a chance to catch the bolt. Bolt comes back hard and bounces forward. YMMV

I started with the gas block at its lowest setting, one round in mag. Fired, and when bolt did not lock back, I increased the gas one increment. I continued to do this until the gas block was full open and still no bolt lock back.

 

[UncleDano]

Appreciate the suggestions to try, thanks to all for your input.

 

[UncleDano]

Compared 10 round Magpul mag that I was using to another Magpul 20 round mag. It does look like the 10 rnd mag follower does not come up quite as high as the other mag follower. Will switch mags at the range tomorrow! Thanks.

 

[ARlife4me]

I know most of you are bolt gun guys, but maybe a few of you may have some suggestions for a fix. I have a AR10 in 6.5 CM that will not lock the bolt open on last shot. Wilson Combat adjustable gas block is full open.

Aero Precision M5 Upper & Lower
Wilson Combat Match Grade Tactical Hunter 18" SS Fluted Barrel
Wilson Combat nickel/boron BCG
Wilson Combat adjustable gas block & rifle length tube
VG6 Precision Gamma muzzle brake
3.8 oz. buffer, carbine spring

Ammo: Norma Whitetail 140gr. SP 2756 fps.

So you built it yourself? I have several 6.5CM barrels of quality manufacturers (proof, cbi, faxon, ap and bsf) and all but 1 takes a lot of tinkering for best function. AP has been the best even with standard rifle length gas system. I have 18 to 22" barrels from them, but they are heavy. If you (with empty mag inserted) pull back on the chargehandle and bolt catch automatically holds the bolt back the you know it is at least going back far enough to catch. Put 2 to 3 rounds in the mag , fire and then check stroke(short, double feed or other). Gas block might not be aligned over the gas port on the barrel(100% or partial aligned). Wilson s well known and makes good products, so quality isn't an issue! It might not have a large enough gas port? What buffer tube do you have? Check free length and count number of coils. Is it a +2 gas system or standard length? PM me for more info or just post more here is fine? Inquiring minds might want to know? I'll give more suggestions after I have more info.

 

[ShtrRdy]

If you're using factory ammo there is something restricting the gas flow. I would give Wilson a call to see what they recommend.