Deserthunter
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Which collapsible stock buffer weight should I use for a l6-inch precision tactical AR-15? I'm thinking H Carbine Buffer.
AR-15 stock buffer weight
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mcb
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Start with a regular one, only go heavier if needed.
greyling22
Member
An adjustable gas block is a better solution to overgassed ar's than heavy buffers.
I've found that on 16" with midlength gas an H2 or H3 will slow down the BCG enough to prevent overriding the magazine and bolt bounce off the barrel extension. CRANE recommends up to H4 on the 10.5 carbines if needed.
Basically you tune down the 900 rpm cyclic speed to a more reasonable 600 where it doesn't batter the action and is more controllable.
Basically you tune down the 900 rpm cyclic speed to a more reasonable 600 where it doesn't batter the action and is more controllable.
Varminterror
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I’m an H2 believer. If I want to go fast, I go light, but for anything precision - which is primarily what I choose to do - H2 is the weight I prefer.
mcb
Member
Just curious why not simply turn the gas down and save the weight?
The heavy buffers were initial introduced to reduce bolt bounce in full auto and burst capable guns that are purposely built over-gassed to make them reliable even when dirty, wet and well worn. For a semi-auto gun bolt bounce is not an issue. An entire adjustable case block is almost as light as the weight difference between an standard buffer and an H2. In a semi auto gun I have never found a reason to run a heavier than normal buffer unless it was way over-gassed. That included 556, 300 BO, 450 Bushmaster, and 30 RAR. My 30 RAR currently has an H1 but that is because the scrap bin ran out of standards. When I first built is it had a standard and ran fine. I pilfered the standard from my 300 BO pistol and threw the H1 in there since it's already my heaviest AR.
Ounces equal pounds, and pounds equal pain.
Varminterror
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There’s no application for which I carry an AR-15 to which this is applicable, with the exception of 3 Gun racing, which I don’t do anymore, such I have no reason to fret over 1.7oz of buffer weight.
Since the OP asked for a solution meant for a “precision tactical” AR-15, I think I’m safe in assuming minimum weight is not a critical parameter of this build. Recoil impulse, however, is likely important.
I also do run AGB’s on all of my personal AR’s, with the exception of one factory original Bushmaster and my HP SR rifle, which is prohibited from having an AGB. Gas and mass must be balanced for reliable cycling, but balancing at one end or the other of the spectrum of cyclic rate are design choices we have.
Buffer weight is one of the major contributors to resist primary movement during the cycle, and one of the major contributors to help ensure chambering and extractor hook up. Mass isn’t our enemy in buffers and carriers, UNLESS we simply want to run exceptionally fast. Which I typically don’t.
Because the gas drive needed for full function with a carbine buffer is the same for an H2. If you tune a gas block so the carrier locks back on the last round with a carbine buffer, it will also lock back on an H2.
The difference is, recoil will be much softer using an H2. Recoil with the carbine buffer is sharp. Shooter fatigue is a real thing. Shooter fatigue sets in quicker with sharp recoil.
The H2 isn’t a heavy buffer. In fact, it weighs less than the original rifle buffer. The carbine buffer came about because they needed a short buffer to fit the shortened carbine RE. When they shortened the buffer, they used only three buffer weights which at the time, were made of steel. It soon became apparent the carbine buffer was too light (strain on the extractor spring, faster carrier speeds, carrier bounce and other problems) so they came up with the H buffer (and the improved extractor spring).
Later, when they created the M4A1 with its heavier profile barrel and fitted with full auto rather than burst, they again had issues with bolt bounce. That issue was fixed with the H2 buffer.
In testing, I find the recoil impulse of 16 inch Colt is softer with an H2 than an H buffer and it runs smoother.
While bolt bounce isn’t supposed to be a problem with semi auto only ARs, the above does suggest that the H1 buffer is at the edge of the performance envelope.
Colt M4A1s are delivered to the military with H2 buffers and they are not over gassed. Another often overlooked fact is a properly gassed AR can be under buffered and will act like it’s over gassed.
It’s interesting to note that bolt bounce has never been an issue with any of the M16 variants fitted with the heavier rifle buffer.
I cannot speak for calibers other than 223/5.56 as I’ve not experimented with them.
I can tell you I’d rather have softer recoil than carry two less ounces.
mcb
Member
I can almost guarantee that I can turn the gas down to were it will lock back on an standard buffer reliably and not on an H2, at least not reliably on an H2. I have never found the H2 that much softer shooting not enough to justify the extra weigh or expense but to be honest I can't remember the last time I shot a 223/556 AR, probably four or five years ago. All my AR shooting is been 300 BO, 450 Bushmaster and 30 RAR that past few years and all of my guns are running standard buffers but the 30 RAR has an H1 as explained earlier. Each to his own. If you like the H2 have at it but you can tune the system with gas just as well as weight.
Ranger99
Member
Sincere inquiry- I'll be the first to declare
that I know little about the intricacies of
AR tuning and function and such
But I have fired bunches of every kind of
.223 from mini14's , AK's, single shot
rifles and my own Contender, some of
the ammo from the good ol days of
$2.00 for 20 rounds to the good stuff.
How can 223 "recoil" be an issue ?
It's pretty much like firing a small bore
muzzleloader
that I know little about the intricacies of
AR tuning and function and such
But I have fired bunches of every kind of
.223 from mini14's , AK's, single shot
rifles and my own Contender, some of
the ammo from the good ol days of
$2.00 for 20 rounds to the good stuff.
How can 223 "recoil" be an issue ?
It's pretty much like firing a small bore
muzzleloader
sarduy
Member
Using an upper with an adjustable gas block, firing 5.56 ammo, both unsuppressed and suppressed, I tested the carbine, H and H2 buffers to see at what setting each would function. I discovered the minimum setting for all three was the same.
Adding a suppressor required closing the gas block a bit compared to shooting unsuppressed.
For most casual shooters, it isn't. But if you fire a lot of rounds in a day as you would in a training class, recoil adds to fatigue. The carbine buffer doesn't increase recoil, but with it's lighter weight, it hits the RE more sharply. It doesn't take long to become uncomfortable when wearing just a shirt.
Also, I find ARs using the lighter buffers develop extraction issues sooner
does it have any cycling issues? Is it carbine or midlength? My experience has been H1's are good, but will not replace a standard weight for one. Standard carbine buffers have been working for decades in 16" carbine barrels. H1/H2 can help with the balance and handling, especially if your lazy and use the carry handle (like me)
Shooting M193 clone handloads (55gr 3200 fps) from my pencil weight carbine with an M4 stock does start to leave marks after a hundred or so rounds.
It is 1/3 the recoil of a 12 gauge pump.
lysanderxiii
Member
A little obscure history on the M4.
The XM177E1 and XM177E2 both used the short, three steel weight, aluminum body buffer we today call the 'standard' buffer. When the M4 was being developed in the late 1980s, Colt figured that it would run better with a heavier buffer, and designed a steel bodied buffer with sliding weights that weighed 5.4 ounces. However, during automatic firing, there were multiple light strike malfunctions indicating the steel bodied buffers were causing bolt bounce. So, in order to complete the test (which was to find the optimum gas port size), 'standard' buffers were used.
A solid steel 5.73 ounce buffer was tried, but bolt bounce was so severe that a full three round bust of automatic fire was impossible to achieve.
Buffers weighing 5.16 ounces with lead-filled weight, and tungsten carbide were tried and found to reduce the cyclic rate, but deemed to costly to produce so the 'standard' buffer was used.
At the time (1987), it was felt that an increase in buffer weight might require an increase in gas port size to accommodate arctic firing (with reduce gas pressure), so the combination of a 0.625" gas port and 2.98 ounce buffer was chosen, as this combination had worked adequately in the XM177E1 and E2.
Fast forward to 1999 and the M4A1 with full auto instead of burst, and light strikes again become a problem. (BTW, this is before the introduction of the heavy barrel.) So, it was decided that in spite of the expense, the tungsten weigh buffer should be used. (It should also be noted that around 1999 some changes were made to the M855 ammunition specifications.)
As to civilian ARs, most of them are rather under-gassed, or over-buffered, point them straight down and you will not get a bolt lock-back on an empty magazine.
wesmonster
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I run a BCM 14.5” mid length and it’s on the undergassed side, a very soft shooter.
I’ve changed weights from std. all the way to H3, never had a malfunction. The only combo that wasn’t 100% was an H3 with a Wolff xtra power spring running Tula. Other steel case was fine, just didn’t like the slower burning Tula. But even weak sauce .223 loads would cycle.
There’s not really a significant difference to me in felt recoil, although I do tend to run H2s or H3s in most of my ARs in other calibers, mainly to slow down cycling to give the mags time to bring up rounds.
unless someone has your identical build, no one’s gonna be able to tell you what’s ‘best’, and if it’s gassed correctly, it won’t matter.
KAK has a buffer kit with various steel & tungsten weights so you can go from std. to H3. You can also just buy a few tungsten weights and if you have the right sized punch you can open your buffer and play with weights.
I’ve changed weights from std. all the way to H3, never had a malfunction. The only combo that wasn’t 100% was an H3 with a Wolff xtra power spring running Tula. Other steel case was fine, just didn’t like the slower burning Tula. But even weak sauce .223 loads would cycle.
There’s not really a significant difference to me in felt recoil, although I do tend to run H2s or H3s in most of my ARs in other calibers, mainly to slow down cycling to give the mags time to bring up rounds.
unless someone has your identical build, no one’s gonna be able to tell you what’s ‘best’, and if it’s gassed correctly, it won’t matter.
KAK has a buffer kit with various steel & tungsten weights so you can go from std. to H3. You can also just buy a few tungsten weights and if you have the right sized punch you can open your buffer and play with weights.
lysanderxiii
Member
Neither, but they are tailored for the pressure curves of M855 and other service ammunition. Your mileage may vary with different ammunition.
The "under-gassed" civilian ARs I refer to are the 16" mid-length with < 0.082", even with "full-power" US made ammunition (and some carbine-length), which is why some of these are iffy with Tula and other foreign stuff.
Most civilians never shoot straight down at -65 F, so the amount of gas delivered by the spec M4 and M4A1 system for normal temperate weather horizontal shooting seems excessive and people use heavier H3 buffers or stiffer springs to slow things down.
I was curious because I've shot civilian Colts with 14.5" SOCOM barrels and 6920s. I never felt any were under gassed or over buffered. That's using the 0.0625 gas port and the H or H2 buffer. I've never felt they were overgassed, either.
I have only had one 16" midlength and that was from PSA. It had a SS barrel and came with a carbine buffer. It was definitely under buffered. It shot much softer and smoother with an H buffer. Once I got the buffer and springs sorted out, it was a good AR. I traded it for something else when I discovered I preferred 14.5" barrels.
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