A controversial statement..discuss

[RAM Engineer]

My belief is that the AR-15 buffer should functionally be considered part of the Upper Receiver Assembly, and NOT the Lower Receiver Assembly. Although structurally, that is where it is located, the appropriate buffer to be used is directly based on barrel length, gas system length, gas port size, bolt/carrier configuration etc. ie, everything about the upper.

I've notice a tendency over the years of people thinking that the buffer is just there to smooth out the recoil impulse. As if they pick the upper they want then choose the buffer that gives them the mildest felt recoil. You choose the buffer that provides reliability under your needed environmental conditions, with your given upper and given ammo (or varieties of ammo).

[MistWolf]

I agree that the buffer is part of the whole system, gas flow, spring rate and reciprocating mass. To your point, I see people asking what buffer they should use with a carbine, or middy, or rifle gas system, without taking into account gas port diameter.

I recently viewed a Chris Bartocci (sp?) video about buffers. He talked about how buffers are important to controlling carrier bounce. In that video, he claimed that during testing, Colt found that heavier barrels gave more bolt bounce. Buffers are clearly an integral part of the system, not just a means to softer recoil.

[scottryan]

My belief is that the AR-15 buffer should functionally be considered part of the Upper Receiver Assembly, and NOT the Lower Receiver Assembly. Although structurally, that is where it is located, the appropriate buffer to be used is directly based on barrel length, gas system length, gas port size, bolt/carrier configuration etc. ie, everything about the upper.

I've notice a tendency over the years of people thinking that the buffer is just there to smooth out the recoil impulse. As if they pick the upper they want then choose the buffer that gives them the mildest felt recoil. You choose the buffer that provides reliability under your needed environmental conditions, with your given upper and given ammo (or varieties of ammo).



Correct assessment.

[bamashooter]

Who knows, who cares. The buffer impacts multiple functions of the rifle. To a small extent some influence of felt recoil can be introduced into the system with the buffer without negatively impacting overall function and operation, thus some folks take advantage of swapping buffers to their liking. You're an actual engineer up in Huntsville or Madison County aren't you? :)

[Iraqgunz]

In my course, I basically teach students that the buffer choice (which in some cases has already been established for us) is based upon the gas system type, barrel length and gas port size. One must also factor in the type of ammo. BCG is more or less moot unless you are using something non standard.

[LMT/556]

I agree that the buffer is part of the whole system, gas flow, spring rate and reciprocating mass. To your point, I see people asking what buffer they should use with a carbine, or middy, or rifle gas system, without taking into account gas port diameter.

I recently viewed a Chris Bartocci (sp?) video about buffers. He talked about how buffers are important to controlling carrier bounce. In that video, he claimed that during testing, Colt found that heavier barrels gave more bolt bounce. Buffers are clearly an integral part of the system, not just a means to softer recoil.
Colt started using H2 with the SOCOM barrel IIRC.
As others stated ammo, gas port and weather conditions (i.e. low temps) play a significant roll in the selection process for weapon reliability reasons. Civilian end users more tailor their selection to less felt recoil.

[Doc Safari]

Colt started using H2 with the SOCOM barrel IIRC.
As others stated ammo, gas port and weather conditions (i.e. low temps) play a significant roll in the selection process for weapon reliability reasons. Civilian end users more tailor their selection to less felt recoil.

That's interesting. I never even paid any attention to the buffer type on my Colt 6721. I was happy with its better accuracy than the 6920 and never stopped to think about the barrel weight maybe affecting ammo reliability, bolt carrier bounce, etc.

Any idea what year they started using the H2 buffer with the SOCOM barrel?

[LMT/556]

No idea, my understanding is an H2 was standard with Colt 921HB.

[Artiz]

That's interesting. I never even paid any attention to the buffer type on my Colt 6721. I was happy with its better accuracy than the 6920 and never stopped to think about the barrel weight maybe affecting ammo reliability, bolt carrier bounce, etc.

Any idea what year they started using the H2 buffer with the SOCOM barrel?

BCG bounce is only an issue on full auto. They used H2's with the SOCOM barrel because the barrel is heavier, which makes the BCG bounce more, the H1 doesn't have enough mass to stop the increased bounce with the SOCOM barrel. If they didn't use H2's the issue of hammer follow would arise (the sole reason for free-moving weights in the buffer, actually), which isn't a good thing when you're shooting full auto.

[5.56 Bonded SP]

BCG bounce is only an issue on full auto. They used H2's with the SOCOM barrel because the barrel is heavier, which makes the BCG bounce more, the H1 doesn't have enough mass to stop the increased bounce with the SOCOM barrel. If they didn't use H2's the issue of hammer follow would arise (the sole reason for free-moving weights in the buffer, actually), which isn't a good thing when you're shooting full auto.


This^

[Doc Safari]

I had actually forgotten that.

[LMT/556]

BCG bounce is only an issue on full auto.Now on technical level I'll argue said bolt bounce will accelerate wear at the cam pin/bolt/carrier interface, as it causes the bolt to unlock then relock. To the OP there's the controversial topic...

[JoshNC]

BCG bounce is only an issue on full auto. They used H2's with the SOCOM barrel because the barrel is heavier, which makes the BCG bounce more, the H1 doesn't have enough mass to stop the increased bounce with the SOCOM barrel. If they didn't use H2's the issue of hammer follow would arise (the sole reason for free-moving weights in the buffer, actually), which isn't a good thing when you're shooting full auto.

Exactly. Carrier bounces rearward after impacting the rear face of the barrel extension. This occurs after the carrier has tripped the autosear which has released the hammer. The hammer impacts the firing pin/carrier cocking ramp while the carrier is traveling rearward, resulting in hammer follow without primer ignition. I had this issue on my M16 when I first swapped to a 10.5” upper and was still using a standard CAR buffer. Interestingly I purchased a Commando 2-piece mechanical buffer that was out of spec and the two pieces were bound together. That produced immediate hammer follow within the second round. H buffer corrected the issues. I have since swapped to h2 and h3 buffers in my M16s.