Supressed SBR Buffer weight to Buffer weight w/Adjustable Gas Block Question

[ndmiller]

I have an SBR 10" 300Blk Suppressed that cycles and performs well with an H2 buffer, regular gas block.

I acquired a 12.5 6.5 Grendel upper I will shoot suppressed (same can) with a SLR adjustable gas block and wanted to get my thoughts verified before hitting the range.

It seems like I can keep the H2 buffer and tune the cycling using the SLR gas block
or I can drop back to a carbine buffer and tune the cycling using the SLR gas block resulting in a softer recoil impulse (due to less buffer weight).

Am I on track here that less buffer weight correctly gassed will have a softer recoil impulse or am I in opposite land thinking this?

Any other thoughts you can provide would be appreciated?

Noah

p.s. Goal is zero, chronograph a few different rounds, lock in ballistic table for ranges and potentially compete (fun) in High Power Rifle Silhouette 200-800 matches at outdoor range.

[Mutant90]

I have a 5.56 11.5" upper with a Superlative Arms gas block and I use a standard buffer and buffer spring with no issues. I set it to have an ejection pattern of 2-3 o' clock so even when suppressed, dirty, and dry it gets enough gas to work. Adjusted this way I get good reliability plus less recoil than a normal gas block. The H2 buffer would cause slightly more felt recoil as compared to the lower weight carbine buffer, especially if you don't tune the gas block to be the lowest it can go. The only problem I can see would be on a full auto gun, where the heavier buffer would help reduce bolt bounce. But even then I would expect the adjustable gas block to fix that due to less gas in the system.

[tehpwnag3]

Yes, you are on track with this, but you must test the system thoroughly if this should ever be intended to go into harm's way.

[ndmiller]

Great, thank you both, glad I've learned something over the years being here. I have the carbine buffer and am going out tomorrow, with 2 different popular ammo choices about 500 rounds.

[Clint]

The suppressor reduces recoil via slowed gases and extra weight to the point that any additional measures shouldn't be required.

Also, since the gas impulse is longer than required, a heavier buffer helps reduce BCG acceleration.

In short, the H2 may feel more balanced with the suppressor.

[ndmiller]

The suppressor reduces recoil via slowed gases and extra weight to the point that any additional measures shouldn't be required.

Also, since the gas impulse is longer than required, a heavier buffer helps reduce BCG acceleration.

In short, the H2 may feel more balanced with the suppressor.

Yeah, I figured I would bring both buffers, while I zero the setup. Exactly what you said is what I thought, then I reread other threads and went back and forth for a while settling on bringing everything.

[MistWolf]

My experience is that, even with an adjustable gas block, the CAR buffer has sharper recoil than an H or H2 buffer. This is with a short barreled 5.56, with and without a suppressor.

[tehpwnag3]

In this case, usually it's because a detent-adjusting GB doesn't have the granularity to make that carbine buffer just kiss the back of the receiver extension. With my SLR, the difference between one or two clicks is a 100% functioning and non-functioning weapon. That's not adequate enough for real tuning. So if I go 6 clicks in, for example, I might have just enough (or even too much) gas to drive three different buffer weights, but a 7th click could cause short stroke malfs with some or all of those. And, as you said, the sharper recoil impulse will come from the lighter buffer due to faster bolt speed. Of course, that makes perfect sense. Short barrels are even harder to tune for as they seem to be less forgiving (narrower tuning range). Add a can and there's another variable to solve for. Ammo selection is also a contributing factor.

To go a step further, when we're talking about really lightening the reciprocating mass, it continues with the bolt carrier; exotic materials and machining. Some systems even require a slightly reduced power action spring. That's just the basics. Even more nuanced would be tweaking the hammer mass and spring, although FCG choices are a lot more plentiful than when this type of thing was in vogue. Muzzle brakes also have their hand in performance and reliability. However, none of this shit is intended for serious use. This is purely shoot fast gamer stuff and not your typical M4C wheelhouse.

My experience is that, even with an adjustable gas block, the CAR buffer has sharper recoil than an H or H2 buffer. This is with a short barreled 5.56, with and without a suppressor.

[Mutant90]

Hmm definitely making me think I need to take my assortment of buffers to the range next time I go. Is the smoother recoil with a heavier buffer really that noticeable?

[tehpwnag3]

Let's say that you don't have an adjustable GB and you have a variety of buffers, from carbine to H3. A good number of shooters will say that a heavier buffer feels smoother because it helps slow down the action speed; the unlock is slightly delayed due to the additional mass which means the gas pressure drops during extraction. This is a good thing. Some people have experienced more "thump" into the shoulder with a heavier buffer. The drawback that I've experienced with a heavier buffer is on the way home, back to battery. That extra mass creates more inertia and your sight picture/sight alignment can dip down more than you want for a faster, accurate follow up shot. If this is happening (and you notice it), try a lighter buffer. The recoil impulse might then be a little sharper, but the sight picture/sight alignment might be more consistent. It's really just a personal preference. Again, reliability is key. Test your system.

Hmm definitely making me think I need to take my assortment of buffers to the range next time I go. Is the smoother recoil with a heavier buffer really that noticeable?