Small Arms Solutions video: "The Buffer - Theory and when to Use What Buffer"

[JediGuy]

I hear Chris’ comments on this as follows:

Based on the gas port sizing used by Colt as required for government weapons with a carbine gas system, the appropriate buffer weight is determined by barrel contour.

From what I gather, the video relays experience based on a specific model(s) of rifle that already had the most important aspect, gas port size, predetermined. For civilian purchasers who can acquire rifles with “more correct” (based on a different spectrum of use and potentially different gas system length) gas port sizes, buffers can be used a little differently. What Bartocci says makes sense to me; however, as non-military users, we have more broad options that do not require such a rigid view of the buffer’s role.

I am not a subject matter expert.

[scottryan]

Thats perfectly fine if he's repeating whatever reason the engineers wrote down as a historical anecdote but that isnt reality. I know for a #fact that there are savvy SF guys out there who will tune their buffer weight specifically to drop the the cyclic rate on their 416s suppressed and unsuppressed. Its also a #fact that there guys out there that had to scrounge H6 buffers because the H1's in their M4s didnt play well with M855A1. If thats not a military application I dont know what is.

The primary driving factor when selecting a buffer is barrel weight to prevent bolt bounce. What he said is the completely 100% correct answer.

Selecting a buffer to “cure” a overgassed gun is a secondary consideration. Notice I said “cure”. Going to a heavier buffer is treating a symptom of an overgassed gun. Reducing the gas port actually solves this problem.

Also, a heavier buffer does nothing to prevent premature unlocking and case head swipe.

[scottryan]

I hear Chris’ comments on this as follows:

Based on the gas port sizing used by Colt as required for government weapons with a carbine gas system, the appropriate buffer weight is determined by barrel contour.

From what I gather, the video relays experience based on a specific model(s) of rifle that already had the most important aspect, gas port size, predetermined. For civilian purchasers who can acquire rifles with “more correct” (based on a different spectrum of use and potentially different gas system length) gas port sizes, buffers can be used a little differently. What Bartocci says makes sense to me; however, as non-military users, we have more broad options that do not require such a rigid view of the buffer’s role.

I am not a subject matter expert.

The problem with this line of thinking is most barrels on the market are not “more correct”

Most of them are POS hobby grade nonsense made to cycle consumer grade garbage .223 ammo.

[scottryan]

You should NOT be choosing buffer weight based on barrel profile. Buffer weight should be based on gas system + gas port size aka how much gas drive is accelerating your bolt carrier. By increasing the reciprocating you are lowering the carrier velocity and allowing more time for feeding and extraction.

Going to a heavier buffer does not slow down intial extraction.

It will not prevent premature unlocking or case head swipe.

[Artiz]

The Army currently uses H2 buffers in their carbines as they are being converted over to SOCOM profiles, if they haven't done so already. Gas port sizes in both barrels is the same. Put an H2 buffer in a 6920 and it will run all day long.

Of course they are. You have to increase the buffer weight when you increase the barrel weight. Has nothing to do with gas port size here, altho gas ports do erode pretty damn fast and change the variables too.

Nobody said a 6920 won't run with an H2...

Thats perfectly fine if he's repeating whatever reason the engineers wrote down as a historical anecdote but that isnt reality. I know for a #fact that there are savvy SF guys out there who will tune their buffer weight specifically to drop the the cyclic rate on their 416s suppressed and unsuppressed. Its also a #fact that there guys out there that had to scrounge H6 buffers because the H1's in their M4s didnt play well with M855A1. If thats not a military application I dont know what is.

You're kidding right?

There isn't much regular military stuff that applies to SF and you know that already.

OF COURSE they need heavier (what buffer weight did you really mean tho? Not H6 I presume) buffers for the M855A1, that shit is as hot as proof loads and is destroying guns in no time. There was/is a big issue with magazine compatibility too. That's an Army shenanigan problem, not an M4 design problem.

[JediGuy]

The problem with this line of thinking is most barrels on the market are not “more correct”

Most of them are POS hobby grade nonsense made to cycle consumer grade garbage .223 ammo.

By “more correct,” I specifically meant gas port sizes like Sionics RGP, BRT’s OPTIMUM design, and the Ballistica Advantage Hanson.

[Iraqgunz]

I think you probably misunderstood my point.

Of course they are. You have to increase the buffer weight when you increase the barrel weight. Has nothing to do with gas port size here, altho gas ports do erode pretty damn fast and change the variables too.

Nobody said a 6920 won't run with an H2...



You're kidding right?

There isn't much regular military stuff that applies to SF and you know that already.

OF COURSE they need heavier (what buffer weight did you really mean tho? Not H6 I presume) buffers for the M855A1, that shit is as hot as proof loads and is destroying guns in no time. There was/is a big issue with magazine compatibility too. That's an Army shenanigan problem, not an M4 design problem.

[vicious_cb]

Of course they are. You have to increase the buffer weight when you increase the barrel weight. Has nothing to do with gas port size here, altho gas ports do erode pretty damn fast and change the variables too.

Nobody said a 6920 won't run with an H2...



You're kidding right?

There isn't much regular military stuff that applies to SF and you know that already.

OF COURSE they need heavier (what buffer weight did you really mean tho? Not H6 I presume) buffers for the M855A1, that shit is as hot as proof loads and is destroying guns in no time. There was/is a big issue with magazine compatibility too. That's an Army shenanigan problem, not an M4 design problem.

Saying just match the buffer weight to barrel profile is such limited thinking. By saying that you pretty much sending people down the wrong road in the regards how they should buffer their guns. As evidenced by the OP's first post.

[ViniVidivici]

So why do we see people running standard weight carbine buffers in carbine stocks with heavy 18 or 20 inch barrels with no ill affects?

[scottryan]

So why do we see people running standard weight carbine buffers in carbine stocks with heavy 18 or 20 inch barrels with no ill affects?

Because the bolt velocity on a rifle is lower than that of a carbine. It does not impact the chamber extension with such force.

Furthermore, these people running rifle length heavy barrels are not running them in full auto. Bolt bounce isn't much of an issue in semi auto.