Buffer system for high backpressure can

November 12, 2026, 01:44 AM

Hey all-

What do you change with your buffer and spring with a high back pressure can?

My Colt 6933 11.5" was running with a stock spring and an H1 buffer. I just installed a stiffer Wolff buffer spring. I have an assortment of buffers from 2.9 oz to 5.6.

What combination would you use? I may take a day and keep swapping until the recoil pulse is less snappy.

Bruce

"The designer of the gun had clearly not been instructed to beat about the bush. 'Make it evil,' he'd been told. 'Make it totally clear that this gun has a right end and a wrong end. Make it totally clear to anyone standing at the wrong end that things are going badly for them. If that means sticking all sort of spikes and prongs and blackened bits all over it then so be it. This is not a gun for hanging over the fireplace or sticking in the umbrella stand, it is a gun for going out and making people miserable with." -Douglas Adams

“It is just as difficult and dangerous to try to free a people that wants to remain servile as it is to try to enslave a people that wants to remain free."
-Niccolo Machiavelli

The trouble with fighting for human freedom is that one spends most of one's time defending scoundrels. For it is against scoundrels that oppressive laws are first aimed, and oppression must be stopped at the beginning if it is to be stopped at all. -Mencken

____________________________

Eeewwww, don't touch it!
Here, poke at it with this stick.

"Dyin ain't much of a livin...boy"

November 12, 2026, 12:11 PM

RNshooter

quote:
Originally posted by badguybuster:
I run a 12.5 with just an H3, no issues. Several manufacturers sell titanium weights you can use to fine tune buffers

I have 2.9, 3.1, 4.2, 5.6 and an OdinWorks adjustable that comes apart with a selection of internal weights. I will be able to find the combination but I was looking for insights to shorten the process.

I usually feel that a stock Colt spring will do the job but with the bolt not closing on a dirty BCG after 100 rounds I am thinking a little more spring pushing on it might be the prescription.

I have never played with buffer spring weight before so I am wondering what new variables that might introduce.

Bruce

November 12, 2026, 12:42 PM

RNshooter

quote:
Originally posted by Mars_Attacks:
I have the KynShot RB5000HP in my SBRs.

What issue were you trying to solve? What level of improvement did it give you?
I will pick one up when I have an extra $150 in the budget for experimenting on a range run. I am trying to make this rifle bombproof as it is my "bump in the night" gun. I like to keep the whizbang cool gadgets for the range toys. If it's 75% as good but 100% reliable, that's what I keep in the defense guns.

Bruce

November 12, 2026, 12:50 PM

Mars_Attacks

I've run the absolute crap out of them with FRTs on my suppressed SBRs.

Hydraulic buffers have been around since the beginning.

I also have a tungsten H3 in the 607. It runs flawless, I have never paid attention to the recoil.

____________________________

Eeewwww, don't touch it!
Here, poke at it with this stick.

November 12, 2026, 03:51 PM

HK Ag

Thanks for this thread, I am looking for a suppressor for the first time for an AR(s).

I have a Colt Socom M4A1 and FN Collector M4, Bushmaster, ... that I want to suppress.

I believe the Colt and FN both have H2 buffers but not sure what spring is in them.

I appreciate those who have come before and willing to share on this.

HK Ag

November 12, 2026, 10:02 PM

ibanda

I have one of every size buffer and spring but I shoot 12.5" 5.56 with a low back pressure can the most. I started it with an A5 system with the regular power spring and an H2 buffer and it ran great from day 1 and I've never tuned it beyond that. I have an H3 buffer on standby for whenever I drop in the FRT.

If you want to run A5 you need all 3 parts to match the A5 tube is about 3/4" longer, rifle length spring and A5 longer buffers. I think they are 10% smoother recoil than a standard carbine setup and the longer length of pull works for me.