AR-10 Issues

[Zen Archery]

New gun. This was the first time it's been fired.
Hand loads. Different charges. Some hot, some mild.

I'd get a box of ammo (if you can find) so you have a constant test medium. Or work up 1 constant load that cycles the gun.
Some charges and powders burn 100% before reaching the gas block and won't cycle.

If the spring and buffer in a Rock River will fit, I can try that. If not, springs and buffers aren't that expensive.

Yes if you have standard try that.

Rifle length. SA adjustable gas block.

Make sure alignment is good and keep it 100% open until you need to tune down.

 

[cohunt]

If you are shaving brass it could have gotten into your bolt -- disassemble the bolt head completely ( extractor and ejector) and clean -- check under extractor for # of o-rings ( use only 1 std)

I've had good luck with springco orange.

I dislike bleed off gas blocks ( the theory never made sense to me)-- I prefer SLR -- make sure its centered over the gas hole- not all gas blocks are designed to sit flat against the barrel ridge/lip

I wouldn't ever buy ar stoner, too many issues in the past. Have you checked head space with gauges? Tolerance stacking can be bad news. I prefer toolcraft.

Polish feed ramps --- adjust gas block properly to lock back bcg after firing 1 round in mag with std weight buffer

Check for compatibility issues with buffer/bcg/buffer tube length/gas tube length --- lots of variances in large frame ar's

Try a different magazine ( I prefer ss/metal or if you really love poly then at least use one with metal lips like the lancer brand) - so you can tweak lips if needed-- as your gouging issue could possibly be incorrect feed angle too

Good luck, building large frame ar's is a whole 'nother animal --- stay away from proprietary ar's, they are a nightmare

 

[ntsqd]

Now several DPMS pattern large frame builds using Lantac BCG's with zero issues. Recommended.

All parts are intended for the same pattern large frame?

 

[Citified]

Sounds like you have a lot of issues with this build.
Polishing the entry lugs on the feed ramps may solve the problem of scratched necks. Don't get carried away. They can be quite sharp and scratch the cases when chambering.

It sounds like your captured buffer spring may be too stiff not allowing the BCG to come all the way back on firing. This affects the ejection distance and the pickup of the next round. They make different spring rates to help this.
I would leave the gas block all the way open, even suppresssd to start.
It is true some powders work better than others for ARs as far as gas production.
Hope this helps is making it cycle right.

 

[kfreeze]

It may be easier for you to tear all of the other stuff off and get a lower kit, buffer tube, buffer, and spring from the company that made your lower and upper. Ar10's have no standard between manufacturers. Even some lower parts are different like bolt catches. Get all things the same to start and it eliminates troubles and gives you a better place to start since you know the parts are all compatible. After that it's easier to figure problems out. Fast rounds like the 22 creedmoor with lighter bullets, and my 204, give a little more trouble with gas. More so if you are running light bullets with longer gas systems. As for the gouging on cases also look at the edge of the chamber to make sure it is slightly rounded and not a sharp edge.

 

[ntsqd]

Most mfg's adhere to one of the two patterns for parts, but that doesn't impose specific dims or tolerances like it does with small frames. DPMS is the more common pattern, but when I see the Stoner name on a large frame part I'm thinking that it belongs to the non-DPMS pattern.

 

[kfreeze]

Most mfg's adhere to one of the two patterns for parts, but that doesn't impose specific dims or tolerances like it does with small frames. DPMS is the more common pattern, but when I see the Stoner name on a large frame part I'm thinking that it belongs to the non-DPMS pattern.

They really dont. About the only thing you can count on is the barrel, hand gaurd, and trigger parts. I've seen different bolt catches, buffer tubes, buffers, and buffer springs just between APF, Aero, and Palmetto AR-10 recievers. Then I finished some 80's and they were even different. It was some used dpms bolt catch, some used armalite. Some used ar15 buffer tubes with a different buffer, some used their own. I gave up trying to figure it out after figuring out the 80's and now buy the upper, lower, lower parts kit, buffer tube spring and buffer, from the same manufacturer.

 

[ntsqd]

They really don't adhere to the dims and tols, or they really don't adhere to one pattern or the other?

IME those who make large frame parts do make them for one or the other pattern (DPMS vs. Armalite) and when they make parts for both they distinctively mark which pattern the part is intended for, but the dims & tols are all their own regardless of which pattern it's intended for.
The lone time that I received an Armalite pattern part it was clear that while it would assemble in the DPMS pattern build, it wasn't going to work correctly.

 

[kfreeze]

They really don't adhere to the dims and tols, or they really don't adhere to one pattern or the other?

IME those who make large frame parts do make them for one or the other pattern (DPMS vs. Armalite) and when they make parts for both they distinctively mark which pattern the part is intended for, but the dims & tols are all their own regardless of which pattern it's intended for.
The lone time that I received an Armalite pattern part it was clear that while it would assemble in the DPMS pattern build, it wasn't going to work correctly.

They don't always seem to stay with one pattern or the other. I looked into a bolt catch that wouldn't release once and it was said online that that company used armalite bolt catches on their dpms pattern recievers. Then I started checking stuff and comparing between all of the manufacturers stuff that I had to know what I need for 80's that I did.

 

[ntsqd]

The 80's that I built were DPMS pattern and DPMS pattern parts all worked fine in them. Aero (I *think*, can check) uppers worked on them as well. Small frame lower parts worked except obviously the mags. The aforementioned Lantac large frame E-BCG's have been flawless.

If large frames are the wild, wild west then 80% large frame lowers seem to be the no man's land within the wild, wild west and I couldn't tell you now whose I bought.

 

[sanwizard]

Gotcha. I'll check the o rings/springs, do some polishing.

What BCG would you recommend? I think I can return this one.

I had similar issues with one of my DPMS 308 builds. Take off the handguard, and check around the gas block for carbon. If so, it may be leaking. Also do everything BRADMOTO mentioned. When you slide the BCG into battery, hold the gas tube with your fingers to feel for any contact between the BCG and tube before it hits home. Also feel for the BCG sticking while you slowly slide it out. If you feel anything, then your tube or block may be out of alignment. I had to swap my expensive BCG for a ToolCraft before mine ran without stovepipes. The BCG is the heart of that rifle.
The buffer spring and weight can also cause issues if not matched correctly to the gas tube length. (Rifle, Carbine...)
Keeping everthing Aero if possible may help with tolerances.

 

[kfreeze]

The 80's that I built were DPMS pattern and DPMS pattern parts all worked fine in them. Aero (I *think*, can check) uppers worked on them as well. Small frame lower parts worked except obviously the mags. The aforementioned Lantac large frame E-BCG's have been flawless.

If large frames are the wild, wild west then 80% large frame lowers seem to be the no man's land within the wild, wild west and I couldn't tell you now whose I bought.

The dpms parts worked in my 80 lowers too, but there was only actual dpms brand and apf uppers that would let the bolt catch work right. I had to mess with buffer tubes too a little. The palmetto stuff didnt fit if I remeber right.

 

[ncwg2boatguy]

New gun. This was the first time it's been fired.
Hand loads. Different charges. Some hot, some mild.

If the spring and buffer in a Rock River will fit, I can try that. If not, springs and buffers aren't that expensive.

Rifle length. SA adjustable gas block.

BCG - AR-STONER LR-308 Bolt Carrier Group Nickel Boron

308 and 6.5cm are same bolt face. It will work since thats parent case for 22CM. Try it.

 

[ncwg2boatguy]

10.5" barrel pistol gas system should run like a singer suppressed or supers with standard carbine buffer and spring more often than not. Gas port info from micro USA if you want to check yours. Higher numbers max size for length. Work up.

BLKUNSUPRESSED0.120 16" car300 BLKSUPRESSED0.106 16" car300 BLKSUPRESSED0.110 6"pistol300 BLKUNSUPRESSED0.069 6"pistol300 BLKSUPPRESSED0.086 9.5"pistol300 BLKUNSUPRESSED0.093 9.5"pistol300 BLKSUPPRESSED0.093 8.1"pistol300 BLKUNSUPRESSED0.104 8.1"pistol300 BLKUNSUPRESSED0.112 8.1"pistol300 BLKSUPRESSED0.086 8.1"pistol300 BLKSUPRESSED0.093 8.5 pistol 300

AR-15 Platform 300 BLK Conversion Supersonic Ammo16" & pistol300 BLKUNSUPRESSED0.0625 16"pistol300 BLKSUPPRESSED0.059 16"car300 BLKUNSUPRESSED0.099 16"car300 BLKSUPPRESSED0.093 9.5"pistol300 BLKUNSUPRESSED0.073 9.5"pistol300 BLKSUPPRESSED0.067 8.1"pistol300 BLKUNSUPRESSED0.076 8.1" pistol300

The 300 Blackout data has been compiled from Micro MOA