Why Is The Carbine Buffer Only 3 oz?

[MistWolf]

With the Carbine Buffers we have-

Construction and Approximate Weights of Carbine Buffers
Standard Carbine- 3.0 oz. Three Steel Weights
H Buffer- 3.8 oz. One Tungsten and Two Steel Weights,
H2 Buffer- 4.6 oz. Two Tungsten and One Steel Weights
H3 Buffer- 5.5 oz. Three Tungsten Weights

Compared to the Rifle Buffer-
Rifle Buffer- 5 oz. Five Steel Weights and One Steel Spacer

If the Rifle Buffer weighed about 5 oz, how did they end up with a Carbine Buffer weighing only 3 oz? Why didn't they start off with a weight approximating the 5.0 oz of the Rifle Buffer? Is it because they didn't think to use tungsten?

[IraqVet1982]

RDT&E. That's why...
Google DoD Acquisition process. I'm assuming the warfighter requirement was for a lighter rifle, why add 5oz if it functions with 3oz.

[Clint]

The rifle buffer is 5.15oz and contains 5 steel weights and a double long aluminum spacer.

IMO, the designers screwed up when they went overboard shortening the receiver extension tube, leaving room for only 3 weights and a shortened action spring.

Perhaps they didn't appreciate the benefits of a properly weighted buffer.

The A5 length with 4 weights and a rifle action spring is what the CAR system should have been in the first place.

[Benito]

Well, given that the Government Profile barrel was chosen (skinny where it should be thick, thick where it should be thin), I am surprised they even put in a buffer at all.

[MistWolf]

The rifle buffer is 5.15oz and contains 5 steel weights and a double long aluminum spacer.

IMO, the designers screwed up when they went overboard shortening the receiver extension tube, leaving room for only 3 weights and a shortened action spring.

Perhaps they didn't appreciate the benefits of a properly weighted buffer.

The A5 length with 4 weights and a rifle action spring is what the CAR system should have been in the first place.

I've always wondered why they didn't do so from the start.

Were the first M4s sold to the .mil supplied with carbine weight buffers? Or is the carbine buffer a legacy from the CAR/CAR clones?

[WS6]

My wild guess is that it works fine in properly gassed guns. KAC MOD 1 and MOD 2's seem to run alright, I guess.

Over the years, ammo grew "hotter", as M855 has more "dwell time" in the barrel than M193, and functions at similar pressure, the effect is that more gas is used in the cycling with M855. Now we have Alpha 1, and so on...

Then take into account all the people wanting to run Tula, and the "We'll just hog out the gas port and it will run with anything!" that many civilian companies went with.

What is the problem with the CAR buffer, CAR spring, and CAR buffer tube? Does it actually HAVE an issue? My answer is: No.

The gas port has an issue. All in the world that the buffer is for, is to counter-act the rebound of the carrier, and a CAR buffer will do this, quite nicely. The gas port should be sized correctly so that only the excess gas required for adverse conditions is pushed into the system. Once this is done, you can run the weapon, reliably, with a CAR buffer, or if improperly done, poorly with an H3. The gas port is the devil in the details, here.

[MistWolf]

My wild guess is that it works fine in properly gassed guns...

Were AR carbines ever properly ported to run with a carbine buffer?

[pezboy]

My guess would be they made the receiver extension the length that it is so that when the stock was extended, it was the same length of pull as the rifle stock. This meant they could only fit 3 of the steel weights they already had on hand in the buffer. It functioned okay so there was no need to mess with it.

The 607 wasn't super reliable, probably partly due to the light weight buffer, and they introduced the XM177 and XM177E1. These were also not super reliable, probably partly due to the light weight buffer, and they introduced the XM177E2.

I wouldn't assume that the carbine buffer should be the same weight as a rifle buffer. Both because the gas port length and barrel length are different and because the recoil spring is different.

[wanderson]

I've got a leftover RRA 5.4 oz buffer from my 9mm build that's running great in my BCM 14.5" midlength. As stated above, it's all about matching the buffer to the gas port. But I prefer the feel of a heavy buffer.

[wildcard600]

My wild guess is that it works fine in properly gassed guns. KAC MOD 1 and MOD 2's seem to run alright, I guess.

Over the years, ammo grew "hotter", as M855 has more "dwell time" in the barrel than M193, and functions at similar pressure, the effect is that more gas is used in the cycling with M855. Now we have Alpha 1, and so on...

Then take into account all the people wanting to run Tula, and the "We'll just hog out the gas port and it will run with anything!" that many civilian companies went with.

What is the problem with the CAR buffer, CAR spring, and CAR buffer tube? Does it actually HAVE an issue? My answer is: No.

The gas port has an issue. All in the world that the buffer is for, is to counter-act the rebound of the carrier, and a CAR buffer will do this, quite nicely. The gas port should be sized correctly so that only the excess gas required for adverse conditions is pushed into the system. Once this is done, you can run the weapon, reliably, with a CAR buffer, or if improperly done, poorly with an H3. The gas port is the devil in the details, here.

All my BCM's run fine with carbine buffers with everything from tula to expensive defense ammo. I constantly see on the internet that i "need" an H buffer "at least" but many thousands of rounds later the guns just keep chugging along with that wimpy carbine buffer. Guess me amd my guns are to stupid to know that they should be unreliable.