Suppressors 101: Rob’s Top 3 Back Pressure Mitigation Methods for Suppressors

Overview:

Shooting with a suppressor can drastically effect the behavior and reliability of your rifle. In this vide Rob covers his favorite 3 methods for back pressure mitigation. There are many options on the market, Rob currently prefers using adjustable gas blocks such as the Riflespeed gas control, low back pressure suppressors and the Bootleg adjustable bolt carrier group.

Skip To Video Topic:

00:00 - Intro
00:31 - Negative Effects of Back Pressure
04:26 - High Flow Suppressors
05:32 - Adjustable Gas Blocks or Piston
09:04 - Adjustable Bolt Carrier Group

Transcript:

Hey everybody, Rob Orgel. In today's video, I want to talk about how to mitigate back pressure. We isolate different topics and we looked at those other suppressors and decide which one has the most back pressure, which one has the least, and then in the end, who really cares? Well, that's a single data point. So in this video, my intentions are to give us more information about back pressure, why it's bad, and then how to mitigate that back pressure. But before I get into that, I want to do a test with you all. First, I'd like you all to give me a comment telling me what you like least about back pressure, and then at the end of the video, I want to know if that has changed. So let's start talking about the negative effects of back pressure. First and most obviously is gas in the face. When we start rocking our carbine and we're putting five rounds into the air to do a non-standard response drill, there's a lot of gases coming rearward into that system that is more than that weapon is designed to have. So it makes its way up along that charging handle into our eyes. Now, there's a lot of different ways to mitigate specifically that gas, but in all, I'd rather mitigate the amount of back pressure completely so as to not just isolate the one thing. So short term, what are the negative effects? Obviously when my eyes are tearing up and I'm doing the, I've been sprayed by pepper spray face, I'm not very good at shooting during that time. So there's that short term effect that I have to take a pause in my target engagement. If this is on the range outdoors like we are here, it might be less noticeable because of the open air, the breeze, and et cetera. When you're in an indoor range, you might get a more realistic to home defense situation. One of many reasons why I don't like shooting indoors is because that gas often has nowhere to go. Even though these indoor ranges do have ventilation systems, it tends to float in your face a little bit longer and it does choke us up a bit more. Long term effects. There's a lot of bad things inside of those gases that we should not be inhaling. So you can feel it in your eyes, you can feel it in your lungs, and later on you might pay a much larger price if you're doing a lot of suppressor shooting. So that's one of many negative aspects. The next one is increased felt recoil. Because we're moving the bolt so much faster, it feels like that gun has 308 recoil when it's really only a 5.56 and that recoil has a lot of negative effects. I don't think I need to explain why I don't like recoil. I'm sure you all can relate. Next let's talk about the effects on the weapon. So there's longevity and I want to break that into two categories. Short term longevity, which almost sounds like a contradiction, and long term longevity, which almost sounds like a redundancy. Well short term, my gun gets gas gunked full of carbon very fast because of that suppressor. So my range date might get cut short because of how much dirtier my weapon becomes and then begins to malfunction.

Long term effects. As I'm running that gun with more horsepower than it should be having, increasing my bolt speed and cycle operations, I might wear out certain pieces to include the bolt lugs or springs within inside that weapon at a faster rate than it was designed for. So in the end I might shorten the overall range day. I might shorten the overall length of life out of my weapon. So those are two things to consider in that negative effects of gas back pressure. So now that we've summarized some of the negative effects of that increased back pressure, let's talk about how to mitigate that back pressure. There are several systems out there. I'm only going to cover a few. If you have a system that you like the most, drop in the comment section. If I haven't already investigated it, I'll investigate it myself because I too am curious. And this is a journey. We're here together to learn, grow and share. We don't need to attack or be mean or remember this is the 2A community. We need to not be volatile and be friendly towards each other and grow this community. We've had so many firearm sales in the last four years. That means probably a lot of new shooters. It is our job as seasoned shooters to mentor those new shooters. So let's try real hard in YouTube, in the comment section and at the gun shop to be friendly towards each other because this is one big communal swimming pool. We need to share it and not pee in it. So be friendly guys. All right. So next is the different ways to mitigate. I've got a favorite three. So my favorite three is going to be the suppressor itself. Knowing how much back pressure that suppressor has and applying it to the right host. Next is going to be at the gas block. Now this could be a gas setting within your gas block or it could be a piston setting within your piston system.

Finally there's the bolt carrier group. So I can use an adjustable bolt carrier group to bleed off access gas. Now let's go back, dissect the three and pick out why I like and dislike each one. First the suppressor. If you have a high flow suppressor so that gases are flowing out the front of your weapon, that means gases are not cycling back through the weapon, keeping the gases out of my face. And now I don't need to have an adjustable system. So let's say if we look at some of the HKAR-15 style rifles, the IAR, the M27, all the different names we have for the HK-416 variant, there is no adjustable gas setting in that. So if I have a flow through suppressor, I'm not increasing my bolt speed recall, those other negative effects, because the gun's not giving me any choices. So I'm going to use a low back pressure suppressor to pair with that weapon. This generally creates good results across the board with the exception of sound reduction. They're not the quietest suppressors out there because gas is flowing through. And that's kind of the opposite of what suppressors need to do to become quiet. Especially if you measure the sound at the muzzle, because a lot of gases are coming forward of the muzzle, as compared to measured at the ear or slightly behind the shooter. Here you'll see a little bit more friendly deviations between the two. Next is at the gas block or at the piston. So if I have an adjustable piston setting, it might be that the weapon itself has one, two, three, even four settings. That's a limited amount of settings, but four is better than none. Two is better than none. In the end, a lot of the times I'll ask the rifle, how much gas are you bleeding off? How I ask this question is I put in one round in the magazine, send the bolt forward and put it in the suppressed setting. I fire that round and I look for how far down the cycle of operations did it go? Did it unlock, pull back a little bit and come forward and not even cock the hammer? That means it's bleeding off a ton of gas. Another example is the Brownells 180, those upper receivers that you can buy and slop on your lowers and folding stock and all that. Those are great and they cut off a ton of gas. So you need a high back pressure suppressor in order to get it to cycle in the suppressed setting. How did I learn that? Exactly the test I just mentioned. So if it comes back far enough to cock the hammer and not extract the brass, that means it's only coming back like 20% of the way. If it's coming back far enough to extract brass, but not far enough to grab the next round, I mean, what do you mean 75-ish percent of the way? Then I need to grab the next round and then last round hold open is the hardest question to answer. Last round hold open requires it to come all the way to the rear where that bolt catch is going to come forward and hold the bolt open telling you you're out of ammunition. This is why I do the test the way I do. One round inside the magazine fire. If it holds open, then that tells you it's going through a full cycle of operations, which means it's not cutting any gas off. If it is cutting gas off, it's only a little bit. I'll give you another great example, the Springfield Armory Hellion. I picked up one of those recently. I'm not really into bull pups, but because it's fully ambidextrous, I decided I'd give it a try. So I ran it in its normal setting. It did everything it's supposed to do. I put it into the suppressor setting and it does not do last round hold open and sometimes it doesn't feed the next round. That means it's only shaving a little bit of gas off. So I paired it with the Huxwork suppressors. The Huxwork suppressors don't add a ton of back pressure and now I've got a perfect pairing. So ask your gun with its adjustable gas block or piston setting, how much gas are you cutting off? You can even disassemble them, pull the piston out and look at the whole diameters. That should also give you a good idea.

Okay, so here we have the SIG 65 Creedmoor DMR designated marksman rifle. You can see there's two different size ports. Now of course it's going to be facing downwards when you're shooting. This is the full size port. This is the reduced port or vice versa. It's good to note that. So small port, large port. What that means is when this wing faces down, you're on the large port. When this wing faces down, you're on the small port. Now some manufacturers will do, for example, call this unsuppressed and this suppressed and some will do standard and adverse. So this is why it's better to instead of read the manual because sometimes they'll give you a little bit of information, but you get much better information from testing your specific ammunition in that weapon. What I just found on this specific weapon with this specific ammunition, which is Hornady ELD match 140 grain, that in both settings it went through the full cycle operations and held open the last round. The smaller port ejected to that ideal four o'clock position, the larger port ejected a little bit closer to the three o'clock position. So I would surmise from that, that for me and my ammunition, this is the ideal port and this is the adverse, meaning give me more gas, not choke off less gas for a suppressor. Finally and lastly, the bolt carrier group. It used to be that GenTech offered a suppressed, unsuppressed bolt carrier group. I find this to be a highly effective bolt carrier group. The problem is because there's only two settings, they give you full gas and then they give you some degree of gas cutoff. So remember the test we did on the other weapon, do that on your specific setup. If it's giving you troubles, then you can change out your springs, being your buffer spring and your buffer weight. This can reduce and increase how much that bolt's going to move. Now I don't think the GenTechs make those anymore, at least I haven't seen them in quite some time. So Bootleg is the current producer of adjustable bolt carrier groups. They have a four way adjustable bolt carrier. I remember when I saw, when I was very excited, I even wrote to myself, I want to be first in line, I want to try that thing. Well, good news, bad news. I've seen a couple very adverse complaints and I too have experienced them unfortunately that when you drop that bolt carrier into your gun at full gas setting, it has robbed some of the gas already. So in some guns, it's like, oh, it reduced recoil. This thing's great. In some guns, it doesn't perform correctly. It doesn't go through a full cycle of operations or once it begins to get dirty, it just stops functioning. So test in the unsuppressed setting, make sure it does everything you ask you to do for multiple magazines. And if you find that it continues to give you a bolt hold open on the last round, then you're good to start choking that gas down and see how much gas it actually chokes off. Once you find that appropriate setting, now you can pair it with different suppressors. But again, know that if it gives you issues, your best bet is to play with the buffer and the buffer spring. And you'll find a whole lot of other deviations between different weapons being the trigger and other such features. My biggest complaint about suppressor, adaptable or gas adjustable bolt carrier groups is that you're bleeding off gas at the ejection port. So if you're left handed like me, a lot of that gas is going to find its way into your eyes. So while it's taking the gas out of the system as to not overrun it, it's putting a lot of those gases in the face and we can be inhaling those gases. So bolt carrier groups are good for a lot of reasons, but in my opinion, the greatest drawback to an adjustable bolt carrier group is one, it takes tuning and two, the biggest drawback of all, it's shoving that gas in your face as opposed to bleeding it off out the front by the suppressor or through that gas system. So hopefully this brings us some closure. Hopefully this brings us some application of the data points in our previous video about suppressor back pressure. We're going to do another video with some of the shorter setups to measure suppressor back pressure in the shorter rigs as we just did in the 16 inch rig. Hopefully this can give you a lighter recoiling, less teary, more fun range experience. If you like this video and you're still here hanging with me after all this talking I've been doing, one, I apologize, two, remember I said I'm doing a test. The second part of this test is now that it's fresh in your mind all the adverse effects of back pressure, tell me now in addition to your previous comment, what you dislike about gas back pressure now. As always, keep training, stay safe and look forward to our next video. Please feel free, like, comment and subscribe.