"What would a $2,000 Geissele Super Duty do that a $500 PSA door buster on Black Friday couldn't do?" - Stopsign32v
That may be, and I respect your expertise, but, at least into the mid-2000s, the H1 was installed in gov’t profile barreled M4s and M4a1s in SOF. I distinctly remember my (Crane trained) armorer going on rants that I didn’t understand at the time about how we were supposed to be using heavier buffers with our NT4s. I was like “dude, can we shoot these ****ing things, or what?”.
This has been my experience. I have some guns with H1-H3 buffers that do seem to be smoother but I have similar guns as far as gas/barrel length that run standard carbine buffers that are equally reliable; IE 100%. Can't name an exact number, but something like 20+ bought/sold over the years.
Last edited by OutofBatt3ry; 07-05-22 at 20:10.
I think I have 6 right now with carbine buffers in them. At least 2 of which are factory Colt carbines and 2 (in current use) that are bull barreled carbine length gas and barrel. (a good bit heavier than a SOCOM barrel FWIW)
(yeah guys, Colt actually made and sold carbines with carbine buffers)
And I got plenty that came with (or I built with) the heavier buffers...
The buffer weight is only one part of it. Just like the barrel weight is one part and the gas port size is one part. I would even go so far as to say the chamber matters as far as the 'felt recoil' or speed / action of the cycling is concerned.
Just because a guy has a heavy barrel - does not alone mean he just 'has to have' a heavy buffer for things to work correctly.
And then being semi auto...
Last edited by DG23; 07-05-22 at 21:33.
When the M4 was first designed they had a 5.4 oz steel buffer with three steel weights. This design did not work at all, they had to stop testing due to the number of failures to fire. (Just to let you know what was considered unacceptable 40 FTF out of 5000 rounds.) It order to continue development testing an expedient of using Colt's Standard aluminum, three steel weight buffer was substituted, while a permanent solution was found. Some things tested in 1987:
- A solid steel buffer, which bounced so bad they couldn't get a full three round burst off.
- A buffer filled with lead shot, that worked acceptably, and
- A buffer with tungsten carbide weights, that worked acceptably.
Meanwhile, the Standard buffer was also working acceptably, and the lead and tungsten carbine filled buffer were projected to have a unacceptable cost, so the Standard buffer was chosen.
Fast forward to 1999, when all the M4s and M4A1 still had the "Government" profile barrel, M4A1s in acceptance testing (with the standard buffer) started to experience a rash of light primer strikes, indicative of bolt bounce.
This was investigated and eventually resulted in the H2 buffer being adopted as standard on all M4s and M4A1s on 21 January 2003..
Why did it suddenly start being an issue after several years of M4 production? The answer lies in the difference between the M4 and the M4A1 - three round burst vs full automatic fire.
The Standard buffer was marginal at preventing bounce. Even as such, bolt bounce did not automatically lead to failure to fire on every round, it was an intermittent problem, maybe once in a dozen or so magazines did the timing line up so that the hammer fell at peak bounce, and sometimes the hammer could muscle through and get the round fire. With the three round burst limit there were only 20 chances for a bounce related stoppage, in full auto, there are 29*. Then there is also a peculiar behavior of the urethane buffer bumper, The elastic recovery time is longer than the cycle time by a wide margin, so after the three or so shots the buffer bumper get continuously compressed until it reaches an equilibrium point. And as it compresses, it get harder and less "bouncy", so the cyclic rate speeds up ever so slightly. So, with the M4, just as bumper gets to the point where it is likely to have problematic bounce start to occur, you stop shooting.
___________
* Two 30 round magazines are fired the first in semi for targeting and accuracy, as well ans semi-auto function and the second in full auto to measure the cyclic rate and functionality.
Last edited by lysander; 07-05-22 at 21:56.
Just an update to my question, I weighed my current buffer today on a postal scale; weighed in at 4.3 oz. Somewhere between an H and an H2 as I understand it. So I guess I’m just going to continue to use the current buffer, based on its weight.
RLTW
“What’s New” button, but without GD: https://www.m4carbine.net/search.php...new&exclude=60 , courtesy of ST911.
Disclosure: I am affiliated PRN with a tactical training center, but I speak only for myself. I have no idea what we sell, other than CLP and training. I receive no income from sale of hard goods.
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