I've been watching this thread and trying very hard to resist the temptation to jump in, but I just can't anymore--I just have too much fun arguing with Potss.
Quick background--I've gone back and forth with him a lot already regarding OSS over at AR15.com so we have history. He seems to be on some kind of anti-OSS crusade and I apologize because I think it's at least in part my fault. I didn't see him saying much about them before I started arguing with him. I expect he'll continue attacking me personally and calling me a shill because he just doesn't have any substance to refute my points. He has a real superiority complex and likes to position himself as an Expert Who Shall Not Be Questioned instead of using persuasion and reason to convince you he's right. If you disagree with him expect him to tell you he knows more about how AR-15s operate than you do.
Now a disclaimer--I'm a self-labeled fanboy for OSS. My general interest is in anything innovative or new. They first got my attention years ago when I had the opportunity to chat with a sales rep face to face, and I've followed them closely since. I admit that I want them to succeed, not because I have any vested interest but simply because I want to see innovative companies succeed and I want better products available to buy myself. When the Gen 4 stuff was on close-out I couldn't resist the low prices and bought 4 of them, but since shooting is not a part of my life right now for various reasons they still sit in the safe along with all my other gun stuff so I have no hands-on experience yet. I try to only relay data and information generated by others to be helpful and/or correct what I think is bad info and I try to never appeal to personal expertise or experience. I know it's easy to miss that nuance sometimes but just think of me as an analyst looking in from the outside collecting and analyzing data and presenting findings and conclusions.
First, a little history... I liked the philosophy guiding OSS from the beginning (a suppressor should be invisible to the action of a gun), but it has always been hard to find 3rd party data that validated their marketing claims. I have yet to see any meter data for the Gen 4 models (I think those were the first offered for public purchase). I don't think I've seen any for the Gen 5 over-the-barrel models either. The Helix flush-mount models came next, and MAC did a little metering for those but it was of limited utility for comparison purposes. From what I remember, he did the 7.62 on an H&K piston rifle and although he promised more coming soon the only 5.56 data he ever put out was recently on a Tavor (where the ear numbers were VERY impressive, especially for a bullpup!). His statement then (and now as far as I know) is that the OSS does better at the ear on 7.62 than anything else he has ever used.
For those of you who aren't aware, that was the end of the old line-up with previous management and after separating from the founder the first new products were the current QD lineup. MAC metered the 7.62 QD recently on an MDR (bullpup) and the numbers were admittedly disappointing--pretty high at the muzzle and not that impressive at the ear. Unfortunately I haven't seen data that tells us how much of that is due to the ejection port being so close to the ear, so those numbers are difficult to interpret.
The Suppressed Nation guys/Hansohn Brothers supposedly did some metering with the QD 5.56 models but they never put out a video with any details. Potss usually doesn't distinguish between 5.56 and 7.62 when making general statements against OSS. Pete at TFB did some metering with 5.56 and 7.62 which at least demonstrated that the muzzle numbers for 5.56 aren't that bad depending on the model--on a 16" with the regular 5.56 model (not the short one) the average was easily under 140 db and the ear numbers were pretty good. 7.62 muzzle numbers were similar to MAC's--mid to high 140's with a 16" barrel. Pete only did 7.62 with a piston H&K rifle, but his ear numbers looked pretty good compared to any other 7.62 ear data I have been able to find. Silencer Shop has done some metering but for some reason they use an MCX for 5.56 and only do 7.62 on a bolt gun so it's hard to know exactly how to compare their numbers to other data. They also don't specify what ammo they are using.
There was a Discreet Ballistics metering event that measured an older model 7.62 on a 300 Blackout bolt gun. For some reason the numbers were surprisingly high even at the shooter's ear--I have heard Dead Air talk about how designs respond differently depending on pressure. For example I think they've said the Nomad actually does better with high pressure than low pressure. I'd like to see more explanation and testing to explore that phenomenon.
To the best of my knowledge that's the only 3rd party data available for these products. All anecdotal evidence I've seen indicates that their back-pressure claims are legitimate, but I've yet to see anybody do any empirical testing to verify it. At one point the Dead Air guy educated me about the difference between back-pressure (high-pressure gas that affects the function of the gun) and blow-back (low-pressure gas that comes back into the receiver and may deposit stuff but doesn't necessarily affect action timing). OSS put out a video trying to demonstrate that when using conventional baffle suppressors, even when the gas is adjusted to compensate for higher back-pressure you still get blow-back coming out of the barrel getting things dirty. Potss claimed it was all BS based on his superior knowledge of the AR and essentially said that these guys who have been doing R&D for many years didn't know what they were talking about, but never offered anything else as proof that they were wrong.
If anybody is interested I can pull together all the relevant links, but I'm just trying to give a big picture overview for anybody who hasn't been following this stuff closely. Here are my summary observations:
-- The older models were obviously heavy and expensive before they got discounted. Users seem to be happy with them--they are usually described as louder at the muzzle but good at the ear with no increase in gas to the face, stuff in the chamber, etc.
-- Most people seem to be happy with POI shift, most report improvement in felt recoil, and I've seen reports of increased accuracy
-- The old mounts/assembly were not simple, but I haven't heard much complaint about the current QD mounting system
-- Whenever you hear somebody say "they're loud", if they aren't distinguishing between ear and muzzle then it's of minimal utility. OSS has always said that they sacrifice muzzle levels to improve ear levels. A big problem is that many people still aren't aware of just how high the ear levels are on a normal AR with a baffle design that gets good muzzle levels. There is plenty of meter data available that shows that if you are getting mid 130's on an AR-15 you are probably getting low to mid 140's at the ear. I've seen some that are in the high 140's.
-- All the hard data that I have seen indicates that OSS probably measures significantly lower at the ear than many competitors, for both 5.56 and 7.62 (with no gas adjustment)
Potss arguments seem to rest on the assumption that every DI AR either has or should have an adjustable gas block. I freely acknowledge that adjusting the gas probably does help with the problem of high ear levels. But when you remove that condition most of what he says is irrelevant. Instead of acknowledging that, he just essentially says your opinions are irrelevant if you don't have an AGB.
The conversation about AGBs is somewhat separate, and I think it's ok to have divergent opinions on that based on the use and missions. Personally I prefer the more universal solution of a low-backpressure design than to accept the compromises of an AGB. In concept I don't like the idea of changing settings every time the suppressor goes on or off, and I don't like the idea of narrowing the operating range and reliability margin (on a fighting rifle). For hunting or recreation it's not so critical, but I think the idea that we should just tell every suppressor buyer to change the gas block and settings on their AR is rather sub-optimal. It's disingenuous not to acknowledge and accommodate the fact that many either don't want to or won't ever do it.
I have a wish list for testing that would help resolve some of these arguments. Sometimes I'm not so much saying what is or isn't as much as pointing out that there isn't solid data supporting what somebody says. It would be very helpful if somebody were to do some videos demonstrating:
-- the difference at the ear between a normal gas block and an AGB with a baffle design with nothing else changing
-- the difference between a 16" barrel and a short barrel (10-11") at the muzzle and ear with nothing else changing (even better if it included OSS and competitors in the comparison)
-- comparing OSS to any popular baffle competitor on the same gun with no other changes (Pete's data comparing to a Surefire product was interesting but unfortunately there was an AGB involved with no way to know if/how much that affected the numbers)
I have more, but those are the big points. I have said before that it would really help the consumer if everybody would agree on some standardization when doing metering. Using a basic milspec 16" AR-15 and a DI AR-10 type would help eliminate some of the variables when comparing one person's testing to another. It would be even better if there was a well-known product that is used as a control group and measured during each session to illuminate any variations between testing sessions. Until the industry establishes an independent testing entity it's an opportunity for some YouTubers to provide the consumers with useful information and help clear up some of the confusion and murkiness in this market.
To be clear, nothing that I say should be construed as advice or recommendation of what to buy, claiming that one product is better than another, etc. I just think that we all benefit when we are informed and educated, so as I look for more information for myself I also try to help clear things up for others if I am able to pass along information/knowledge that I've acquired elsewhere. I hope something in here is helpful to somebody!
My big issue with Potss is not that I'm necessarily claiming that everything he says is wrong, or that I'm an expert on anything, but if you ask him for evidence to support the things he says, he just tells you he knows what he's talking about and you're wrong. It's a serious disservice to anybody who might be reading and not commenting (now or later) NOT to push back on that!
I'm not going to dig into everything he's said here, but I do want to ask him about one thing. Potss, you said:
But when the muzzle readings climb about ~145db, the splashback means the shooter will actually experience a secondary SPL (from muzzle) that is louder than the initial one (from chamber unlock). So you can have great at the ear numbers that don't mean jack if the muzzle is over 145db, and the more above the louder it will be to the shooter's ear. EX: on a 16in .308, it won't be <140db.
If that is true, then how do you explain both MAC and Pete getting ear numbers below 140 on a 16" 7.62? How is the meter measuring a lower number first and then not picking up on this second pressure wave that's even stronger coming back from the muzzle?