Carbine Buffers in high end AR's

[Pappabear]

I got a new SR15 in trade, brand new and it came with a SR15 carbine buffer, not and H or H2 or.... Any idea why top end manufacturers would use carbine buffers? Ultimate reliability ? Hottest gun that throws any brass out and cycles?

Also, very interesting, I put a BCM A5 buffer system in the gun and it calmed it a little bit, but is still tossing brass at 2:00 with can. Much like it did before the A5. I don't think it does so with as much energy but I was surprised it didn't calm my gun more. I think it cycles perfectly with a my can, but was a bit worried it tame it down too much. Thought it would have had a more taming effect, I am 100% satisfied but it surprised me.

PB

[prepare]

Is it a mid length gas system? Do you know the gas port size?

Every spec on the AR you buy or build should have data to support it IMO. Unless it’s for T&E and you’re collecting data.

[Stickman]

I got a new SR15 in trade
PB

Everyone is getting cool stuff but me!!!

[mack7.62]

Because it's gassed properly so standard buffer works fine.

[markm]

Because it's gassed properly so standard buffer works fine.

Proper gassing should put ANY Carbine actioned AR at an H2 buffer if you subscribe to the idea that matching the rifle buffer system as closely as possible is best. (which I do)

I have (arguably) under-gassed guns that I had to step down to an H1 carbine buffer. (14.5 middies with .078 ports) I'm unaware of ANY gun that runs best on a carbine 2.9oz buffer. LMT does or did still ship guns with that buffer too.

[Stickman]

Proper gassing should put ANY Carbine actioned AR at an H2 buffer if you subscribe to the idea that matching the rifle buffer system as closely as possible is best. (which I do)

I have (arguably) under-gassed guns that I had to step down to an H1 carbine buffer. (14.5 middies with .078 ports) I'm unaware of ANY gun that runs best on a carbine 2.9oz buffer. LMT does or did still ship guns with that buffer too.

I'm not sure that I consider properly gassed barrels to be H2, I tend to lean more to wanting to see them as H1s if all things are done correctly. That gives a standard buffer the ability to be used for lighter/ weaker loads or small ports. The H comes in where it should be, but allows H2 to be used for hotter ammo, and that would be putting the H3 in dedicated can guns.


I'm not sure that any of it matters when we are talking about the SR15. I've read KAC stating they designed their buffer for their uppers, which makes sense. Of course they don't design those buffers for full time can use, but I guess it would be nice if they had that as an option. The A5 offers up a lot of adaptability, but I do wonder if a H2 or H3 would tame that upper best for PB.

Please update us with whatever you guys figure out. If you need to borrow some various weighted A5 buffers to play around, just let me know. Its not that often that I need to play around with my set, and being without them for awhile wouldn't inconvenience me at all.

[markm]

I'm not sure that I consider properly gassed barrels to be H2, I tend to lean more to wanting to see them as H1s if all things are done correctly.

Which is fine. My logic is derivative of RSilvers old posts here. I subscribe to the logic that the Rifle buffer system (or Vltor A5 too) is the optimal DI gas gun AR buffer formula.

In order to mimic it as closely as possible within the constraints of the Carbine action spring and R.E., you want to pick the H2. On a quality un-suppressed AR, I might not be able to distinguish and H1 vs and H2. But you get that shitty carbine buffer, and man does the bolt speed start to take off!

Shooters should line up 2 or three ARs on a table, and shoot 3-5 rounds, quick change to the next gun, and compare while shooting 50 yard steel. It is amazing the nuances you can realize when you jump from AR to AR like that. Even on guns I think are pretty closely set up... I can feel real differences report, impulse, etc.

[Disciple]

I'm unaware of ANY gun that runs best on a carbine 2.9oz buffer. LMT does or did still ship guns with that buffer too.

Meanwhile:

May 1, 2022

#3

KineticPerformance said:
Is there a general consensus that there is a bottom end on total reciprocating mass or can you generally go to a 1oz buffer as long as it's reliable. It's currently soft shooting but I'm trying to push the limit.

No, no bottom limit. I've got a rifle with an empty buffer and 4 rifles with the Taccom delrin buffer that weighs .6oz and I've even tested with no buffer just out of curiosity.
The adjustment window is wider than I would've guessed, the 4 delrin buffer rifles are all adjusted to lock back using a 55gr @ 2650fps load and are only mildly overgassed with my 77gr/2700 and 69gr/2800fps loads, and among those rifles are mid, intermediate, rifle and rifle +1" gas systems. So yeah, it works a lot better than the internet would have you believe.

[Pappabear]

I'm not sure that I consider properly gassed barrels to be H2, I tend to lean more to wanting to see them as H1s if all things are done correctly. That gives a standard buffer the ability to be used for lighter/ weaker loads or small ports. The H comes in where it should be, but allows H2 to be used for hotter ammo, and that would be putting the H3 in dedicated can guns.


I'm not sure that any of it matters when we are talking about the SR15. I've read KAC stating they designed their buffer for their uppers, which makes sense. Of course they don't design those buffers for full time can use, but I guess it would be nice if they had that as an option. The A5 offers up a lot of adaptability, but I do wonder if a H2 or H3 would tame that upper best for PB.

Please update us with whatever you guys figure out. If you need to borrow some various weighted A5 buffers to play around, just let me know. Its not that often that I need to play around with my set, and being without them for awhile wouldn't inconvenience me at all.

Thanks for the offer Stick. I’m a complete goofball because after buying that A5, I found a geiselle super duty buffer and wire in my 55 gallon drum of shit and an H2. Both of which would have been interesting to play with. Now the A5 is in there so I’m sticking with it. I had some other A5 buffers we might play with but I’m happy how the gun shoots suppressed. It feels gassed strong enough to cycle everything but still pretty smooth.

Interesting what Disciple offered. People taking stuff to limit certainly gives some perspective. Using the lightest or softest recoil is not my goal, I am mostly interested in reliability. Which can be achieved in a number of ways as the Hide post illustrates.

We ran my gun with real hot loads, soft loads and can on/off. All ran like a top.

PB

[Stickman]

People taking stuff to limit certainly gives some perspective.
PB

When Centurion Arms first released barrels they used a real small gas port, which was awesome. Double taps from standing at 25 yards wasn't a big deal, and out to roughly 50 yards it was doable. The gun couldn't get dirty (we used .223 duty ammo), but clean and wet she was crazy smooth shooting with negligible recoil. With 5.56 ammo it could get dirty and was still super smooth.