AGPinochet tries to definitively with a relatively high degree of confidence try to settle the discussion as to whether 6.8x51 military pressure loadings with EPR Projectiles can consistently penetrate body armor at ranges where that actually matters / AGPinochet plays amateur ballistician armed with YouTube videos and extrapolations
I have been extremely lazy at getting around to writing this post but below is what sparked it's impetus
Last month the US Army through a digital handbook gave us what I believe is the first instance of a confirmed, first hand source on the velocity of the XM1186 Ball round for the XM7 at any given distance. That velocity being 3159 fps measured at 78 feet from the end of the suppressor (I'm assuming the issued suppressor was attached because it's now a standard issue item) which is close enough that it's *essentially* muzzle velocity from an unknown barrel length (Which I assume is the 13in of the XM7 because that's how short Sig could make the barrel of the XM7 without having to go even retarded crazy higher on the cartridge pressure (and a little bit of foreshadowing, here, I don't think it would really matter if the fps is 100-150fps higher through the XM-250)
Before we get into the meat of this post here's a (very much inferior) post I made a loooong time ago on this very subject
I have my doubts that the Sig Sauer 6.8x51 Hybrid cartridge is the Armor Obliterator that people on the internet make it out to be (at least without Tungsten Carbide) and I am making this post to detail these reasons and offer a chance at critique of my thought process.
Ok here comes the dump of YouTube videos that if you make a lot of inferences and assumptions about support my argument 100%
At 13:29, An M80A1 projectile at 3475fps is fired against a Hesco 4800 plate without soft armor backing situated 45 feet away, at 15:33 it was shown that the round did NOT penetrate
Interestingly, an M2AP round fired at 2932fps did penetrate as shown at 6:38
At 18:27, An M80A1 projectile at 3521fps is fired against a Hesco 4601 plate without soft armor backing situated 45 feet away, at 19:17 it was shown that the round did NOT penetrate
Once again an M2AP at 2958fps penetrates at 6:28 but I think this one is a fluke/result of plate damage because the exact same projectile going faster didn't penetrate.
At 8:39 onwards 3 rounds of handloaded 6.8x51 with XM1186 EPR projectiles are fired at an Adept Colossus without soft armor backing situated 45 feet away at the following velocities (this one isn't really fair as the Colossus is ridiculous)
-3105fps as recorded by Garmin chronograph (3095fps as recorded by second chronograph)
-3143fps as recorded by Garmin chronograph (3127fps as recorded by secondary chronograph)
-3073fps as recorded by Garmin Chronograph (3030 fps as recorded by secondary chronograph)
At 11:15 it's shown that no rounds penetrated the plate
At 18:22 an M80A1 projectile going 3543fps as recorded by Garmin Chronograph (3524 as recorded by secondary chronograph) goes up against the same model of plate and fails to penetrate as seen at 18:45
At 10:42, an M80A1 projectile at 3509fps is fired against a Russian 6B43 "Granit" plate without soft armor backing, situated at 45 feet, at 11:17 it's shown that the round did NOT Penetrate
At 5:16 An M2AP projectile impacts with an initial muzzle velocity of 3217fps and penetrates as shown at 5:48
*a bunch of uninformed jingoistic to the point of parody spouted by a Dunning-Kruger NAFOboomertroon nonsense about how muh heckin RuZZia doesn't issue it's legions of penal slave troops body armor and if they do it's made of cardboard and all Russian soldiers run around with ssh-40's with WW1 era mosins and also all the body armor that doesn't exist because it was never manufactured due to """ corruption""" was sold to Western Larpers*
Silence, shut up, be quiet.
At 13:15, an M2AP going 3229fps at the muzzle hits an XSAPI of unknown Revision, situated at 45 feet, with Chinese soft armor backer (Revision J was the most modern as of 2022)
At 13:30 an M2AP going 3183fps At the muzzle impacts
At 13:57 an M80A1 going at an unknown velocity at the muzzle (we can make guesses based on previous data) impacts
At 15:25 an M2AP going 3233fps at the muzzle impacts
M2AP's # 2 and 3 were the only ones to penetrate but they were the last two rounds to hit the plate (in addition to an API I didn't list here for consistency) respectively so you can probably chock those up to a degraded strike face
At 13:47, an M80A1 going 3394fps impacts an RMA 1192 with no soft armor backer situated 45 feet away, at 17:00 there's a confirmation of no penetration
At 2:20, an M80A1 going 3463fps out of the muzzle impacts an "Engarde Level IV' (Never heard of these probably chinese) with no soft armor backer situated 45 feet away and does not penetrate
I think I've made my point
Notes/Conclusions
-It seems pretty apparent to me that military pressure 6.8x51 can't be expected to penetrate quality Civilian/Foreign Military body armor, especially at any considerable distance, without the use of tungsten core ammunition.
-While I have read that the slimmer profile of the .277 XM1186 may aid in increasing penetrating capability you've seen numerous instances of .308 M80A1's going at considerably higher speeds fail to penetrate and I doubt that a refined profile is going to make up for 2-400 less fps
-EPR Style projectiles may be negatively affecting penetrating capabilities as Brinell hardness needs to be reduced as to not mutilate feed ramps in short order, conventional steel core projectiles don't have this problem
-Russia/China can easily produce any of the above armor plates (and obviously demonstrably have in the case of the Granit) and even if XM1186 could pen their current plates it can't do so at any considerable distance and they could either fully rectify or drastically reduce the range at which penetration is enabled by adding 1-2mm of thickness to the ceramic sections of their plates and maybe a little more soft armor/backing.
-If you're going to cope about this remember that XSAPI's (that yes, have been refined over the years) are 20 year old technology which must like all armor plates are based on 80 year old technology
-"500 meter armor penetration" is either fuddlore, referring to 1.5mm sheet metal or the world's shittiest "totes for real Level III" plates you get for $50 on Alibaba
-Also, at least in the Ukraine, small arms are kind of irrelevant combat wise, with somewhere between 80-95% of all dead and wounded being inflicted on both sides by explosions/fragmentation according to various sources I've read and remember, both sides cannot realistically expected to one shot penetrate the other's armor. This is not to say small arms are irrelevant, they just don't kill people.
. But if it's just going to be nonsense then why even bother with firearms.
