Heavier AR-10 Buffer: Would It Help?

R

rg1911

Gunny Sergeant
Full Member
Minuteman
Oct 24, 2012
846
339
72
Laramie, Wyoming
#1
I was told here that my AR-10, chambered in 260 Rem, was showing symptoms of over-gassing, such as dented case mouths and the occasional partial eject (case at right-angle to ejection port) while chambering the new round. The bolt does not always lock back on an empty magazine. Since this is my match rifle, even occasional stoppages are not desired.

I always shoot suppressed and have an SLR adjustable block that I've been tweaking, with minimal total success. One-quarter-turn can take it from over-gassing symptoms to insufficient gas.

The block is centered correctly over the gas port in the barrel, at least according to my 'smith's bore scope.

The question, then, is: Would installing a heavier-than-stock buffer help the ability to make fine-tuning adjustments? If so, are there any specific weights I should try, and are there any recommended brands/manufacturers?

Thank you,
Richard
 
#4
I run heavy buffers in all my 6.5CM's and .308's , all with SLR Adj. GB's and Tubbs .308 Flatwire recoil springs.

What specific stock are you running ?

Is the 260 broke in enough ? ( How many rounds through it ? )... if less then 100 rds.. fire more to break in.

Does the extractor have pointy ends or rounded ?... Pointy ends tend to "grab" the case rim and not readily let go of the case.

Pic from the internet...

!____________________________________________SuWHaxU-912480.jpg



I would make sure the extractor is not pointy... then try a heavier recoil spring and heavier buffer weight.

Given it not locking back every time... it does sound like it is cycling fast.

It only takes a few milliseconds of slowing the cyclic speed to help with "over-gassed" symptoms.

Given your added pressure from being suppressed, I would tend to think slowing the cyclic speed would help.

Currently, how many clicks from closed is your SLR adjusted to ?... mine all run at 6 clicks open from closed ( with heavy buffers and the Tubbs ) unsuppressed.
 
Last edited:
#6
I only get partial ejections with one of my mags, a 10 rd Pmag, my 20 rd pmags work fine. Failure to lock back in my LR308 is a sign of either a too heavy of a buffer spring or undergassing ie neither of which would allow lock back.

I run an H3 buffer on a rifle gas system (non adjustable gas block), in an A5 buffer tube. I also run a clipped rifle spring, comes out the same length as a carbine spring but is a touch stiffer
 
#8
Right now, everything is pretty stock (no pun intended) with a standard Armalite buffer and spring in a Magpul PRS Gen 1 stock. I hope to avoid a heavier spring; with my arthritis, the stock spring is about all I can hold on to.
Before I got the adjustable block, I did use a heavy buffer. However, I thought I wouldn't need it with the new block, so sold it here. Teach me to part with parts. I just wish I could remember from where I purchased it.

Thanks, Richard
 
#9
JP silent capture standard and a superlative is what i have in mine. Have experienced zero issue. They are pricey but i believe you can get spring and weight kits for them if you really wanna fine tune.
 
#11
rg1911 said:
Right now, everything is pretty stock (no pun intended) with a standard Armalite buffer and spring in a Magpul PRS Gen 1 stock. I hope to avoid a heavier spring; with my arthritis, the stock spring is about all I can hold on to.
Before I got the adjustable block, I did use a heavy buffer. However, I thought I wouldn't need it with the new block, so sold it here. Teach me to part with parts. I just wish I could remember from where I purchased it.

Thanks, Richard
Click to expand...

Usually I recommend running a heavy buffer in suppressed large frame AR's. With more mass you end up with a wider window of operation and an easier time tuning the gas. Since you're already running suppressed, I'd strongly recommend the JP Silent Captured spring (JPSCS2-10H2). You eliminate the spring noise and also get a smoother cycling rifle.
 
#12
A Tubbs spring and a buffer in the 5+oz range would slow things down.

Measure your buffer to see if you need a 2.5” or a 3.25”. KAK makes a good 2.5” 5.3oz and if 3.25 any H3 AR15 buffer will work.

The Tubbs spring has more pressure on the carrier than stock when the bolt is in battery and less when compressed. In other words it changes less from extended to compressed than round wire springs.

Then just adjust your gas to get good 4:00 ejection.

Tubb Precision AR-10 Flatwire Buffer Spring (Fits both Carbine and Standard length stocks)

High Performance Tubb Precision Flatwire Stainless Steel Buffer Spring for AR-10 Rifles and Carbines
www.davidtubb.com www.davidtubb.com


Mine with the above runs great (now that I’ve fixed extractor tension) and several others I know of have gone to the Tubbs spring and H3 and went from frustration to elation.
 
#13
From the OP " I hope to avoid a heavier spring; with my arthritis, the stock spring is about all I can hold on to."

From what I read off the Tubb site the Tubb spring will be harder to manually rack by quite a bit.... While it does have a better consistent weight, the initial weight on the bolt is just about 50% heavier than stock

This thought is based on the spring tension in battery numbers they give compared to stock, plus they also say it's heavier than a heavy duty spring... Would also be interested in what buffer tube configuration they used for tests. Pictures on the Tubb site use a rifle buffer as an example

Can anyone educate me on this?
 
#15
KTAK said:
From the OP " I hope to avoid a heavier spring; with my arthritis, the stock spring is about all I can hold on to."

From what I read off the Tubb site the Tubb spring will be harder to manually rack by quite a bit.... While it does have a better consistent weight, the initial weight on the bolt is just about 50% heavier than stock

This thought is based on the spring tension in battery numbers they give compared to stock, plus they also say it's heavier than a heavy duty spring... Would also be interested in what buffer tube configuration they used for tests. Pictures on the Tubb site use a rifle buffer as an example

Can anyone educate me on this?
Click to expand...
The spring works in carbine and rifle tubes.
The max tension is less than a standard spring, so the maximum pull required will be less than your stock spring.

A good charging handle with a nice wide place for fingers will do more for your arthritis than what we’re talking about here.
 
#16
Lawless said:
The spring works in carbine and rifle tubes.
The max tension is less than a standard spring, so the maximum pull required will be less than your stock spring.

A good charging handle with a nice wide place for fingers will do more for your arthritis than what we’re talking about here.
Click to expand...
Overall less tension but the starting pull even with an oversized handle would suck for a guy with arthritis, simple physics... increased pressure on the bolt means higher tension to charge it by hand...

And I am working on some custom work for someone with arthritis (not gun work) and simply increasing the size of the charge handle won't necessarily fix it by any means
 
Last edited:
You must log in or register to reply here.

Similar threads

Thumper580
What determines brass ejection angle/position
Replies
8
Views
505
Jscb1b
Jscb1b
V
Another dead horse, AR tuning.
Replies
7
Views
552
thedude824
T
Island_Mando
AR Gassing help
Replies
18
Views
811
flogxal
F
R
First AR10 build, what did I do wrong?
Replies
14
Views
736
45-90
4
darkfader
300 Blackout AR Malfunctions
Replies
18
Views
535
roosterpig
roosterpig
Top Bottom
Back
Home
Forums
Merch
Alerts