Can Subsonic Ammunition Penetrate Armor? Part 1

Hey everyone, welcome back to the range. I've got some subsonic ammunition to test out today. If any of you remember my test from last time, if not I'll throw a card maybe here or here or here or here of the 5.7x28mm test where I tested M855A1 trying to get subsonic out of it to see how it would perform. Unfortunately the 5.7x28mm has a 1-9 twist barrel which is not fast enough to stabilize M855A1 or M855. So I have my AR-15SBR which has a 10.5 inch barrel but it has a 1-7 twist. So we're going to check velocity, bullet stability, and then we're going to test them against some body armor. For another test that maybe some of you haven't seen, I've tested SB193 which is a 5.7x28mm round which is either a 55 grain full metal jacket or the newer lots are 62 grain. They're just a plain Jane lead core full metal jacket but they have the ability to penetrate multiple panels of soft 3A and some of the thinner rigid polyethylene panels. So we're going to test these two today to see if they can mimic that performance and while we're at it, we've had some other theories that people have brought to us about the 9x39mm round, the AP version of that, being able to penetrate level 4 body armor. Now I don't have 9x39mm yet, let alone the AP, but we've got M2AP that we're going to test to see if that's subsonic as well and we'll shoot that against the level 4. And we'll just kind of lump this into a big giant, hey, it can subsonic penetrate armor. Let's get set up for this test. Okay we're testing some subsonic ammunition, this is M855 loaded with 4.5 grains of trail boss, this is a 10.5 inch barrel, we're going to check for velocity and bullet stability. Okay now we have 4.8 grains of trail boss, back to the M855, after we're done shooting these we'll go check the target for bullet stability at approximately 15 yards. 10.64, 10.51, 10.84. Looks like that's a good range to keep subsonic in the M855. Now for the M855A1, let's see where we're at. 9.66, 9.82, 1.007, cool. They all stayed subsonic, at least I did something right. Alright now we're going to test some M2AP at subsonic speeds. We have some trail boss again, start at 9 grains and work our way up. This is a 163 grain projectile, we'll shoot this out of the 1 in 10 twist barrel to make sure we're going fast enough for a longer, heavier projectile going subsonic speeds, and we'll see what we get. 9.89, 9.20, 8.71, okay. Let's go check our target for stability. There are our three group types, I'd say I'm very pleased there. I got good clean holes at approximately 15 yards, which when I've tested this before, out of the 5.7, that has a 1 in 9 twist barrel, and it's simply not fast enough for this longer projectile to stabilize at subsonic velocities. So we know that the 1 in 7 twist barrel definitely can stabilize these 62 grain projectiles going subsonic. Here's our subsonic M2AP, good clean holes out of that at 15 yards. That's pretty good. Usually, if we have any stability issues, you notice them right away at 15 yards, and you've got keyholing or really wild accuracy results, and they're staying within each other. You know, I'm moving some of them just to make sure I'm getting good clean holes. So that's a good positive note. I think we'll stick with the 16 inch for this test for the 308. Okay, now that we've checked our velocity and we've substantiated that we are subsonic and that they are stable, let's test them against a piece of body armor. We have an AR-500 armor level 3A Rheimlig, pretty much a budget, run-of-the-mill, meets the NIJ level 3A specifications, approximately 15 feet. We have a clay briefcase as a backer. Our clay's nice and warm, so we should get a good representation of back face. We have our Pro Chrono Digital as always. Hopefully, you can see the velocity on the screen there. I should work on getting a bigger monitor or something out here so you can see velocities better, but this is a lot easier than trying to run a b-roll camera on the chronograph and constantly moving it around. So first up, we'll shoot the M855, then the A1. What I've been trying to do lately is roll a picture of the round down in the corner so you guys can see a close-up of what it actually looks like because it's kind of hard sometimes when I'm out here by myself to zoom in on the ammunition, get it to focus, and then zoom out. Velocity, 1084. Now the A1, 984. Here was our M855. We're a little on the low side there. I was hoping to be up there, about an inch and a half away from a previous shot, but we should still be pretty good. Here was the A1. What do you all think? Strap out of the way here. We have two clean holes. Right through this panel, right through there, and right through there. So since it can penetrate one panel, let's try two, and then if it can't stop it then, then I have some rigid level 3A plus that we can try. We have the briefcase set back up. We have the level 3A Rimelig on the backside, and on the front, we have their level 3A hybrid from AR500 Armor. It's a little more of a premium offering. It's rated to stop .44 mag at 1,600 feet per second, whereas typical 3A is rated at 1,400 feet per second. Same order, the M855, then the M855A1. We may have to adjust the chronograph after each shot. I'll put AR500 Armor's link in the description below. They have quite a bit of offerings from steel armor, to polyethylene, to ceramic, or their soft offerings. Velocity 1084. Let me go move the chronograph here, and now the A1. 1064. That was really low on that shot. Let me load another one. Sorry about that. 967. Here was our M855 shot, right on the money that time. The A1 is low there on the first one, and right where I wanted it on the second one, I should have took a little more time there. What do you guys think? We are clean through all three shots on the first panel. That bottom one's definitely not a fair hit. Then on the second panel, here's the good shot there, and right there. We still have three pass-throughs there. One there, one there, and one there. Obviously this one has a little more damage down there, because it didn't have much plate to stop. I kind of have a feeling, based on our performance that we've achieved in the past with SB193, that we're going to need a rigid panel to stop this. Give me a second, and I'll set up for that test. Our rigid plate of choice is the RMA Armaments Model 0226 plate. This is a 100% polyethylene plate. Same order as always. The M855 first, then the A1. My chronograph a little on the low side. Velocity 1142. That one was supersonic, just by a hair. Now the A1. 1007. I don't know if you guys could see that, but I saw some wood flying behind my briefcase, which means we probably have a penetration. Anybody want to place any bets? If M855 was able to do it over M855A1, the straps are coming off. Here was the M855 shot right there. Right where I want it to be, actually. It's a quarter of an inch off to the left. The A1 shot, quarter inch up and to the right, but far enough away from subsequent shots to make them good, valid hits. We have two holes there, everyone. Penetration is clean through. Those are some interesting results. We've tested M855 and A1 before at SBR barrel length velocities, and we were able to stop them in the shorter barrel length against the level 3 1078 plate from AR500 Armor slash RMA Armament. We may need to get that plate back out, but in a real world scenario, these velocities that we're hitting here subsonic were our equivalent to about 450 to 500 meters out. So if you engage someone at that distance and you were able to hit them with and they were wearing soft armor, you have the potential to penetrate that soft armor. How much damage it would do after penetrating, it's hard to say. I didn't have any gel blocks today, but more science data because for science. Now let's test our M2AP subsonic theory. This is a level 4 plate from Militech. This is actually a new offering. This is their alumina oxide level 4, 6 pounds. It actually has strike face foam protection on it like NIJ 06 calls for. We remember the drop test rig clay this time. So as always, we drop test two times per NIJ standard to the best of my ability. Let's go throw this on the briefcase and run our test. We've verified that we have good velocity and stability out of these. We have our Yankee Hill Phantom M2 attached to here. We have the plate backed out to approximately 45 feet with our giant clay briefcase. We have a few spots marked. Internet lore says 9x39 subsonic AP was able to penetrate a level 4 plate. I think a few times out of 7 or 8 shots. Again, I don't have 9x39. We're just going based on a theory of a slow moving projectile that is less prone to being broken apart because it's not traveling at high speeds. This may be a complete fail. We're going to find out. We're going to start at the top left of the plate. Velocity 901. Now the right side 973. Back to the left side 887. Right side again 965 unless that didn't read. 1020. Let's actually go check that plate out and see what we're doing. I'm hearing some ricochets so either it's penetrating or something else is coming off the plate and let's be a little on the safe side. I'm not sure how well you can see this. I have a b-roll camera there. I feel trying to do the tripod is a little better than me shaking with my phone. But here's shots 1, 2, 3, 4, 5 and if you can't tell you should be able to see. Here are the bullets. The core is still there on the first shot and then the second. Even that ceramic does a pretty good job at subsonic speeds of breaking up that core. There's the third. The fourth's in there and the fifth sticking down there. Let's see what the back side of the plate looks like. I'm gonna guess it's probably unscathed as far as back face goes. Yeah there's there's some dimples on the back side there but nothing to write home about. I sure would like to be able to get my hands on some 9x39 to test this theory that I read about where it's able to penetrate a level 4 armor. Now the 9x39 is significantly heavier than even this. I do believe it's in the 250 to 290 grain area and it has a completely different design. I do believe it has an exposed penetrator which may help its case here. Just wish I could get my hands on some. But as far as M2AP being subsonic and its ability to penetrate a level 4 plate I'm going to say that myth is busted. Well there you all have it. We busted one theory about a subsonic round being able to penetrate a level 4 piece of armor which has a ceramic strike face which is really tough. We messed around with our M855 and our M855A1 and were able to duplicate what we've seen with the 55 grain or 62 grain SB193 from 5.7. I'd like to continue testing that ammunition on a thicker level 3A or possibly level 3 polyethylene plate to see if its ability to stay intact will help it penetrate at such low velocities. As always I'd like to thank you all for watching. My Patreon supporters Millitech for providing me with these new plates. We'll run some tests on one of the other ones that we have in the future. Until next time catch you at the range.