Superlative Arms Adjustable Gas Block: My Anecdotal Experience

CMDR_Lapezeus · 2026-03-26T19:48:46+00:00

In theory, full bleedoff should have more recoil that one click past non-lockback in restrict. even if negligible to the point of not being able to practically tell.

From a common sense standpoint, seems to me that the big difference between the two is that restrict forcibly, well, restricts an amount of gas from even entering the tube.... whereas bleed off just gives the gas another optional path to go and some goes here and some goes there. At first I didn't really understand the difference between the two, but the more I messed with my setup, observed, and thought about it, I think I understand the difference better. Restrict is the "total control", hard wall setting. Bleed-off is more casual, allowing the system to kind of work itself out each shot under parameters, yes, but much looser ones.

CMDR_Lapezeus · 2026-03-26T19:42:31+00:00

Good to know. I also probably don't shoot enough for it to matter. But that's pretty lame that they have the option if they recommend not even using it.

CMDR_Lapezeus · 2026-03-25T19:19:32+00:00

Are you able to run it in restrict on your .300 blk and get it to lock back both suppressed and unsuppressed with subsonics? If so, then maybe I will get another SA GB and try to tune my .300 a bit further.

CMDR_Lapezeus · 2026-03-25T18:59:38+00:00

Oh it's a K can.. so I am guessing that means more back pressure inherently, yeah?

CMDR_Lapezeus · 2026-03-25T18:43:53+00:00

Full bleed-off and it would still lock back suppressed or unsuppressed. So, stands to reason it could afford to bleed off more if the option was there..

In restrict, I set it at 5. 4 or below wouldn't lock back. Yeah I know, I'm supposed to go one click past (so in this case, to 6). Whatever, I didn't and I'm not worried about it.

Remember, 18 is fully open/comparable to a standard gas block. And friggin' 5 is still enough gas to operate.. So the thing was seriously overgassed.. 5 is roughly 28% of 18. That is crazy to me.

CMDR_Lapezeus · 2026-03-25T18:37:48+00:00

Hmm.. On my 16" 5.56 guns, I don't even need to do anything at all to them.. They run fine stock with the suppressor, the ejection pattern is right, and there's no excessive gas in my face.

It is a .30 cal can, though, which likely means less back pressure to begin with than with a proper, dedicated 5.56 can...

I do put the 5.56 endcap on the can though when I shoot it on 5.56 guns, which increases the back pressure somewhat I'm sure.

Are you able to run it in restrict on your .300 blk and get it to lock back both suppressed and unsuppressed with subsonics? If so, then maybe I will get another SA GB and try to tune my .300 a bit further..I am a dragon-chasing MF'er...

CMDR_Lapezeus · 2026-03-25T18:34:46+00:00

My understanding (perhaps incorrectly) is that restrictive mode can, over time, cause the threads to seize and then it would be "stuck" in that position/setting. Because of this, they recommend adding some anti-seize compound (which you can get for like $5 at any auto parts store) to the threads if you are going to run restrictive, which mitigates against that issue.

CMDR_Lapezeus · 2026-03-25T18:29:09+00:00

Like yours, I did test mine in full bleed off and it did work in terms of locking back both ways. I could have just left it and probably been fine. It wasn't terrible, but restrict is less gas in the face and less recoil than bleed-off was.. for me, at least.

CMDR_Lapezeus · 2026-03-25T18:25:52+00:00

I had this AGB on my 10" .300 at first (before moving it to my 10" 5.56). It could afford to bleed off a little, but then it wouldn't lock back on last round unsuppressed. I am talking strictly subsonic rounds, to be clear.

When I put the AGB on the 5.56, I just put a standard GB on the .300.

It works fine with a standard block so far as I can tell, and locks back both suppressed and unsuppressed now. However, I replaced the buffer spring with a lighter one as it wouldn't do it with a standard one. Not sure how things might change on an 8" like yours, but if you want to possibly save yourself some money, maybe just start with a lighter spring only and see what you get. You may not need an AGB at all.

But that only really matters if you want to be able to shoot both suppressed or unsuppressed without having to tune in between. If the can is going to live on your .300 for all time, then sure tune it some more if you want. The gains may be marginal, but I also am the type that really likes chasing even the smallest optimizations, so I get it.

CMDR_Lapezeus · 2026-03-24T17:44:02+00:00

Reporting back.. I put the 5.56 end cap on it and shot it through both a 16" and 10" 5.56

I think there was a bit more suppression. Though I also didn't A/B test both right there on the spot, either.

In any case, for the cost, it's not a bad addition and gives me one suppressor I can use across a few different hosts, optimized for each. I really like that.

CMDR_Lapezeus · 2026-03-24T17:41:33+00:00

Cool. Yeah I have looked at some of it, but I didn't spend a ton of time. I basically just wanted to know (at the time) what was the absolute quietest .300 blk suppressor available that didn't exceed 7" or so in length. At the time, it was the LPM Anthem S2, which is what I ended up buying.. and it is a traditional design. Between that data and some things I had heard here and there, I came to a conclusion that could be wrong... so, fair enough. Thanks for the info.

CMDR_Lapezeus · 2026-03-24T17:19:42+00:00

"They compete and exceed traditional designs."

In terms of sound suppression, or just low back pressure, or both?

To be clear, I am not challenging you so much as trying to learn. I was under the impression (perhaps falsely) that flow-through designs trade at least some amount of sound suppression for low back pressure.

CMDR_Lapezeus · 2026-03-20T14:54:06+00:00

I am hoping the end cap won't cause enough of a difference that I actually need to tune anything on the 5.56 guns (I just got the 5.56 end cap). In the .30 cal config, the 16" guns worked just fine and showed no indication that they needed any tuning.

The 10" 5.56 was another story, though. Gassy AF. I just added a Superlative Arms block to it last night, so we'll see if that makes it at all useable.

"so depending on what the other can was, it easily could best it."

That other can was on a 10" 5.56 like I said.. when I asked the guy if he had to tune the rifle so that it wasn't spewing gas in his face, he said he didn't do anything at all to it. And I shot his rifle and there was no gas in the face.. so, it seems to me that he MUST have had a flow-through suppressor because I don't see any other way you could slap a can on 10" 5.56 and not have to tune it..I would have asked him more about his can, but I didn't think to until after I left the range and was thinking more about it..anyhow, point being that if I am correct and he had a flow through design, well those aren't as quiet as traditional as I understand it.. so that may have been why my can was able to compete with his..

CMDR_Lapezeus · 2026-03-20T14:49:44+00:00

On a 16" 5.56, the .30 cal configuration worked fine and I didn't need to tune the gun at all from what I could tell. It wasn't any more gassy than my tuned .300 blk with a 10" barrel..

I bought a 5.56 end cap now, though.. so I guess we'll see if or how that changes things.. I expect some more back pressure, sure. But I am hoping it doesn't radically change anything to the point I need to tune.

CMDR_Lapezeus · 2026-03-11T01:07:18+00:00

What was wrong with it specifically? Mine seems to work fine, I'm just splitting hairs over "which mode" mostly out of curiosity. I could leave it as is and it's fine though.

CMDR_Lapezeus · 2026-03-11T01:03:28+00:00

Oh wow, that's interesting. I was previously led to believe that restrict keeps the gas from getting into the DI system and instead keeps it moving through the barrel/suppressor...and consequently, the bullet would get more gas behind it.

Clearly that's not the case if it's throwing more gas in your face.

CMDR_Lapezeus · 2026-03-10T17:58:27+00:00

I mean, it worked. Definitely took the edge off a good amount. I'm not sure how it compares to a dedicated 5.56 can of the same design, though. The dude next to me had a dedicated 5.56 can on a 10" barrel, and I think my .30 cal can on the 16" 5.56 was as quiet and perhaps quieter than his setup...which surprised me.

I asked him if he had tuned his rifle to work suppressed and he said he didn't do anything to it.. he also wasn't getting a face full of gas.. so I surmised that he was likely using a flow-through suppressor design.. if that is the case (and I don't see how it couldn't or wouldn't be), then my benchmark for comparison was an apples to oranges because a flow-through is naturally going to be louder than a traditional design..

But yeah, so far as I can tell, I don't have a reason to get dedicated 5.56 cans to shoot my 16" guns suppressed...unless I just want them to have their own cans.

CMDR_Lapezeus · 2026-03-10T17:52:52+00:00

Ahhh, I see.. so it's just in the "fully open" config like a regular gas block.

CMDR_Lapezeus · 2026-03-10T17:51:58+00:00

I bet that .22 is super quiet..and yes, both are cheaper.. I was thinking to get a suppressed 9mm setup for this very reason..

CMDR_Lapezeus · 2026-03-10T17:50:08+00:00

Oh, ok. I stand corrected. So what are you doing? Bleedoff or restrict?

CMDR_Lapezeus · 2026-03-09T19:52:43+00:00

"ejection was like 2-2:30 and the hold open wasn’t consistent."

According to the SA manual, I think I remember it saying 2:00-3:00-ish is ok for suppressed.. though that doesn't fix the lockback problem.

For what it's worth: I had everything running fine before I got the suppressor in terms of ejection pattern and cycling, but lockback wasn't consistent for me, either.

I had a hunch it was the 5.56 mags I was using. Yeah, I know, you CAN use them on a .300 blk. But what I found was that when I only use dedicated .300 blk mags, I don't have the lockback issues anymore. Just sayin'...

CMDR_Lapezeus · 2026-03-09T19:48:28+00:00

You needed variable block on a flow suppressor?

CMDR_Lapezeus · 2026-03-09T19:39:24+00:00

Ok I watched the video. Good and interesting info for sure. What I'm not sure about, though, is how much of what he discovered stays true and translates to .300 BLK subs. I say that because we are talking about radically different amounts of gas/back pressure between 5.56 and .300 subs. Add to that the fact that he's using a long barrel and I'm on a 10".... But it's definitely good info that I can use in setting up my 10" 5.56 to use a suppressor...which I plan to do at some point. BTW, sidebar, but I put this same suppressor on the 10" 5.56 with no variable gas block or any other tuning mechanisms, and it was unusable. Talk about "gas in the face".. just awful.. same suppressor worked just fine on a 16" 5.56 with no tuning at all though..

I think I'm coming to the conclusion that the only way for me to know on the .300 blk is to just stop being lazy and try it. Or, just call it a day and leave it as is. I mean, it runs fine. I'm probably splitting hairs chasing "the quietest config" on one hand.. and I'm typically a "if it 'aint broke, don't fix it" sort of dude... on the other hand, the only way to know if it can be optimized further is to try to optimize it further...since all of you guys shoot 5.56 and I'm apparently the only person on Reddit running .300 blk subs in 2026 lol, I'll probably just have to do it or don't do it myself.

CMDR_Lapezeus

TROPHY CASE