AR-10 buffer system

ratton

Sergeant
Jun 21, 2009
502
4
18
58
Nevada
#3
I use a hydraulic buffer on my AR10. I was skeptical at first but, combined with my Surefire muzzle break it really makes the system a pleasure to shoot
 
Jun 13, 2007
333
3
18
PNW
#4
With that Vltor ( Magpul UBR uses that length tube ) buffer tube length, and a .308 AR BCG, you will be able to use standard AR15 buffers.
 

Saf3sh00t3r

Gen. Sum Tin Wong
Feb 10, 2017
1,519
7
38
Mckinney TX
#5
The JP Vmos is pretty awesome especially if you will shoot suppressed. It does require the silent spring too. On the less expensive side slash heavy buffer is great too, he has multiple options, email him and ask him what he recommends.
 
Jul 31, 2017
49
4
8
#6
Like sprinco orange extra heavy buffer spring. Then short buffer carbine buffer weight that I can put tungsten in it. That setup give more bolt lock than any rifle buffer spring combo that I have tried including buffers with 4-5 tungsten in it & 3 different springs.
 
#7
My recent 6.5 Creedmoor build gave me a headache with short stroking. It had a std 308 buffer. The gas port was a lil undersized so I opened it up to .078 as my research showed (I believe it was as per Krieger). Still had issues went to a flat wire and still had same issue. In the end I found that the AR-15 buffer worked very well, but then was overgassed, and purchased the JP adjustable gas block. Point being since the AR10 is not standardized sometimes they take tinkering. What may work for one may not work for another. I should also note it was having cycling issues with reloads. Specifically, a mid range load of imr4350 and 140 nosler CC
 
Nov 18, 2011
8
0
1
31
South Texas
#8
I have an 18" .308 that was overgassed causing failures suppressed. I contacted Clint at heavy buffers.com told him exactly what I had and symptoms. He recommended his a spring and buffer of his and it has been flawless ever since.
 

Coyote Kev

New Hide Member
Apr 12, 2018
11
3
3
#9
I went with a hydraulic buffer and tubbs flat wire spring on a recent 6 creedmoor build. It definitely shoots smooth and cycles nice. I'm running suppressed with an adjustable gas key. Maybe I'm missing something... but I'm not sure why people mess with heavy buffers and tungsten when you could just adjust gas flow. Adjustable gas blocks/keys are relatively inexpensive and easy to install.
 
Likes: KYAggie

NukeMMC

Damn Bubblehead
Mar 3, 2009
915
4
18
Harrisburg, PA
#10
Maybe I'm missing something... but I'm not sure why people mess with heavy buffers and tungsten when you could just adjust gas flow. Adjustable gas blocks/keys are relatively inexpensive and easy to install.
My GAP10G2 in 260 had a rifle length 20" barrel and SLR AGB. I ran it with an Ops Inc 3rd Model silencer and with the AGB adjusted so it would barely lock back on an empty mag, it would leave BAD swipes on the brass even with moderate (2700fps with 140s and 2800fps with 130s) loads. Once I added weight to the buffer (which already had a Tubb flatwire spring) it reduced the brass damage SIGNIFICANTLY.
 

Coyote Kev

New Hide Member
Apr 12, 2018
11
3
3
#11
My GAP10G2 in 260 had a rifle length 20" barrel and SLR AGB. I ran it with an Ops Inc 3rd Model silencer and with the AGB adjusted so it would barely lock back on an empty mag, it would leave BAD swipes on the brass even with moderate (2700fps with 140s and 2800fps with 130s) loads. Once I added weight to the buffer (which already had a Tubb flatwire spring) it reduced the brass damage SIGNIFICANTLY.
Well there you go. I figured I was probably missing something. So now I have 2 questions. What is going on there with the swipes that the heavy buffer fixed? Do you notice an increased recoil impulse with the heavy buffer?
 

LawnMM

Harbinger of Sarcasm
Jul 5, 2009
1,630
35
48
Colorado
www.accuracy-tech.com
#12
It's a timing issue, if the dwell time is too short the bolt unlocks while the case is still hot and under pressure. As the bolt rotates to unlock the soft, hot brass, is swiped by the ejector rubbing the case head.

I've played with this stuff quite a bit and the answer is probably an extended length gas system and a custom port size.

For the rest of us that aren't paying for that, you need heavy components. Full weight bolt carrier, ultra heavyweight buffer, flatwire spring, adjustable block. Even that didn't alleviate all pressure signs on mine.

I'm about to try a superlative arms block to see if I can extend the dwell time more by blowing off what I don't need to cycle the action. Mine was so overgassed when I put it together it sheared off my extractor claw at a match. Live and learn.

Lightweight components are hip and cool on an AR15, if you're stepping up to the big boy you want heavy components.
 
Oct 2, 2014
35
6
8
Kentucky
#13
Well, I guess your mileage may vary applies to the "need" to run a full weight carrier and a heavy buffer in a 6.5 CM. I'm running a .8 oz Taccom buffer (The period in front of the 8 is not a typo, it's really under one ounce), JP 308 carbine spring, Toolcraft titanium bolt carrier 11.8 oz, JP enhanced HP bolt, and SLR titanium gas block with a 20" Faxon barrel with rifle length gas system and I have not had problems with cycling nor brass swipes. I have NOT yet run it suppressed so I'm not sure what the result would be if I did. Seems to work great for me and weighs about 3/4# less with these components.
 
Last edited:
Aug 28, 2013
9
0
1
#14
I use the JP silent capture system, i have it in my 308 and a one of my 223. Very pleased with them, biggest problem i have is i don't want to shoot my other Ar15 that doesn't have the JP system installed. I'm going to have to eventually order another one.
 

NukeMMC

Damn Bubblehead
Mar 3, 2009
915
4
18
Harrisburg, PA
#15
Well, I guess your mileage may vary applies to the "need" to run a full weight carrier and a heavy buffer in a 6.5 CM. I'm running a .8 oz Taccom buffer, JP 308 carbine spring, Toolcraft titanium bolt carrier 11.8 oz, JP enhanced HP bolt, and SLR titanium gas block with a 20" Faxon barrel with rifle length gas system and I have not had problems with cycling nor brass swipes. I have NOT yet run it suppressed so I'm not sure what the result would be if I did. Seems to work great for me and weights about 3/4# less with these components.
The additional gas pressure dwell time you get with the can is what killed me. Mine was just fine with a plain muzzle or the Hellfire brake. Add the can and the brass got mangled.
 
Likes: KYAggie
Oct 2, 2014
35
6
8
Kentucky
#16
The additional gas pressure dwell time you get with the can is what killed me. Mine was just fine with a plain muzzle or the Hellfire brake. Add the can and the brass got mangled.

Thanks for letting me know, that makes sense. If I run mine suppressed, I'll make sure I have a heavy buffer to install just in case I experience the same brass destruction.
 

NukeMMC

Damn Bubblehead
Mar 3, 2009
915
4
18
Harrisburg, PA
#18
I ran 10ozs (all buffer weights were tungsten) in my buffer also. GAP10s use Armalite BCG, so it's a full-weight BCG. Cut and dry, an good AGB (SLR, Superlative, etc) rifle length or + length gas, heavy mass cycling parts and proper spring will keep you from having throwaway brass when you run suppressed. If you tweak gas port sizing, it's probably easier, but if you run unsuppressed, you may starve your system. It seems to be a pretty narrow window with these 6.5mm cartridges. Any words from the 6mm crowd?
 
Oct 2, 2014
35
6
8
Kentucky
#19
Man, what's the recoil impulse like with all that mass moving around? I guess if your gun weights north of 10# it probably doesn't matter. My 6.5 CM is a lightweight build just under 6.5# with no scope, so I definitely would not want all that mass moving in my rifle. I may not mess with suppressing it if I need that much extra weight in the system to not trash the brass.

LawnMM, I'll be interested in knowing if a Superlative AGB makes a positive difference for you. I have one on a 16" AR15and it works well for me, but that's a very different volume of gas than a 6.5 CM.
 

LawnMM

Harbinger of Sarcasm
Jul 5, 2009
1,630
35
48
Colorado
www.accuracy-tech.com
#20
I'm hopefully getting a chance to try it tomorrow. I didn't even mention the tubb carrier weight system. The BCG and Weight are 1lb6oz alone 😉

It did help increase dwell time and alleviate the swipes and hurling brass about 12ft to the 2pm I started with.

I'm hoping the new gas block is the last piece of the puzzle to really get everything dialed in nicely. I even have some of the original hand load to try for comparison.
 
Likes: KYAggie
Apr 12, 2018
8
1
3
#21

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NukeMMC

Damn Bubblehead
Mar 3, 2009
915
4
18
Harrisburg, PA
#22
I'm hopefully getting a chance to try it tomorrow. I didn't even mention the tubb carrier weight system. The BCG and Weight are 1lb6oz alone 😉

It did help increase dwell time and alleviate the swipes and hurling brass about 12ft to the 2pm I started with.

I'm hoping the new gas block is the last piece of the puzzle to really get everything dialed in nicely. I even have some of the original hand load to try for comparison.
Pretty sure Tubb doesnt do his carrier weight system anymore.
 

padom

SuperMod
Staff member
Mar 13, 2013
6,033
214
63
Southeastern, Pennsylvania
#23
Ive built many 6.5cm semi's. I have tested many different buffer setups for both full mass and LMOS carriers. I have found the JP LMOS carrier with a JP SCS Heavy is the perfect combination for not only reliability but brass life. Not a mark on the brass with this combo. I also only use JP QPQ barrel extension which are already honed before being coated. This also minimizes shoulder/neck damage that you see on BAT barrel extensions where the sharp corner gouges the neck/shoulder.
 

NukeMMC

Damn Bubblehead
Mar 3, 2009
915
4
18
Harrisburg, PA
#25
Ive built many 6.5cm semi's. I have tested many different buffer setups for both full mass and LMOS carriers. I have found the JP LMOS carrier with a JP SCS Heavy is the perfect combination for not only reliability but brass life. Not a mark on the brass with this combo. I also only use JP QPQ barrel extension which are already honed before being coated. This also minimizes shoulder/neck damage that you see on BAT barrel extensions where the sharp corner gouges the neck/shoulder.
Do you shoot with a can? I am getting ready to build a Mega MKM and my 260 experience has me second guessing. I am looking at the SCS but have a gut feeling about wanting the extra mass on a normal carrier for longevity/reliability and drop a little weight on the recoil assy. Seems to me you have Scandale do your barrels? Do you get any specific gas port size? May have him do mine.
 

LawnMM

Harbinger of Sarcasm
Jul 5, 2009
1,630
35
48
Colorado
www.accuracy-tech.com
#26
You're going to be disappointed if you spend the cash on all that JP stuff. If you shoot factory ammo it'll probably live up to the hype, if you're handloading lightweight anything is going to show how finicky it can be.

I had some blown primers with factory Hotnady. If you handload for performance you're a lot closer to the upper end of the pressure curve than factory stuff.

In my experience that's where the swipes start and the overall beating it puts on the gun.

The superlative arms gas block btw, pretty sweet. Keeps the heat buildup down a bit, doesn't seem to do anything great pressure wise over other adjustables. However, given the choice, I'd rather vent it than block most of it and heat up the barrel and GB.
 
Feb 17, 2018
35
5
8
#27
I run the Aero 308 carbine buffer and spring, it was inexpensive and has worked perfectly for me so far. I have a few JP Silent Captured springs in AR15 builds that work really well so I'm looking to drop one of those into the AR10 eventually.