Supersonic load on 4.5" barrel able to defeat IIIA body armor?

[Ghost12three]

If it were me, I'd give up 3.5" of compactness for a 60% increase in energy. But then we may have different priorities.

Despite the energy losses, am I going to defeat IIIA or lower levels with supers through this 4.5" barrel?

Defeating most body armor depends on speed, so can that size barrel do this at your planned engagement range?

Level IIIA
9 mm FMJ at ~1,400 fps
(~427 mps)

.44 Magnum Semi-Jacketed Hollow Point at ~1,400 fps
(~427 mps)

And I believe it's 6 hits in a certain square inch which it must stop to be certified. But, it's no guarantee, I've had 5.56 both get defeated and get stopped by level IIIA panels. Didn't send any 30 cal at those panels, so not sure if some would of been stopped or not, but I can tell you that a perp would have to be real committed to keep going after getting hit with a rifle round, whether it gets stopped or not.

I was able to dig out some data on velocities with supers on many barrel lengths, the shortest being 4 inches. It exceeds the 1,400 fps mark by around 100 fps.

[dellet]

Despite the energy losses, am I going to defeat IIIA or lower levels with supers through this 4.5" barrel?

Defeating most body armor depends on speed, so can that size barrel do this at your planned engagement range?

Level IIIA
9 mm FMJ at ~1,400 fps
(~427 mps)

.44 Magnum Semi-Jacketed Hollow Point at ~1,400 fps
(~427 mps)

And I believe it's 6 hits in a certain square inch which it must stop to be certified. But, it's no guarantee, I've had 5.56 both get defeated and get stopped by level IIIA panels. Didn't send any 30 cal at those panels, so not sure if some would of been stopped or not, but I can tell you that a perp would have to be real committed to keep going after getting hit with a rifle round, whether it gets stopped or not.

I was able to dig out some data on velocities with supers on many barrel lengths, the shortest being 4 inches. It exceeds the 1,400 fps mark by around 100 fps.

You will likely need more velocity than that and bullet construction will be everything.

A good example might be the Barnes Blacktip. It is a barrier blind bullet, so will have a good chance of defeating the armor, but needs 1350 fps to expand reliably. Most rifle bullets will need more than that to expand.

Defeating the armor just to have the bullet pencil through what's behind it is kind of self defeating.

[Omega]

Despite the energy losses, am I going to defeat IIIA or lower levels with supers through this 4.5" barrel?

Defeating most body armor depends on speed, so can that size barrel do this at your planned engagement range?

Level IIIA
9 mm FMJ at ~1,400 fps
(~427 mps)

.44 Magnum Semi-Jacketed Hollow Point at ~1,400 fps
(~427 mps)

And I believe it's 6 hits in a certain square inch which it must stop to be certified. But, it's no guarantee, I've had 5.56 both get defeated and get stopped by level IIIA panels. Didn't send any 30 cal at those panels, so not sure if some would of been stopped or not, but I can tell you that a perp would have to be real committed to keep going after getting hit with a rifle round, whether it gets stopped or not.

I was able to dig out some data on velocities with supers on many barrel lengths, the shortest being 4 inches. It exceeds the 1,400 fps mark by around 100 fps.

Like I said, some may penetrate, while others will not. I was shooting 5.56 out of a 14.5" barrel, at upwards of 2500fps, so everything else being equal, they should all been through and through shots. So the most honest answer to your question is, maybe.

[cdl]

Ya know, these vests can be penetrated at pistol velocities too. A bullet that turns inside out on the surface probably isn't going to do what you want it too either. Unless you have velocity to spare, and even then, it's still about the bullet.

Military Arms Channel
Subsonic 300 Black Out vs. Kevlar Body Armor

https://www.youtube.com/watch?v=euucD2YJq4w

[withoutremorse42]

Here's some velocity data from 4.75", 6", 6.5" barrels with various ammo, 5" data added soon.

Also, shameless plug for my article.

https://loadoutroom.com/51926/ultra-sho ... up-part-2/

[Omega]

Here's some velocity data from 4.75", 6", 6.5" barrels with various ammo, 5" data added soon.

Also, shameless plug for my article.

https://loadoutroom.com/51926/ultra-sho ... up-part-2/

Be nice to see a follow up to see how it can defeat, or not, Level IIIA body armor. If it doesn't penetrate, or partial, it would be nice to see how much deformation there is. Maybe a top 10 300Blk hunting/SD bullet shootout.

[withoutremorse42]

Here's some velocity data from 4.75", 6", 6.5" barrels with various ammo, 5" data added soon.

Also, shameless plug for my article.

https://loadoutroom.com/51926/ultra-sho ... up-part-2/

Be nice to see a follow up to see how it can defeat, or not, Level IIIA body armor. If it doesn't penetrate, or partial, it would be nice to see how much deformation there is. Maybe a top 10 300Blk hunting/SD bullet shootout.

I think I have a couple IIIA plates around that are disposable. Not gonna shoot my III+ plates though. Need more Barnes Black tips, need some more IIIa's and I'll get a video up

[Omega]

Here's some velocity data from 4.75", 6", 6.5" barrels with various ammo, 5" data added soon.

Also, shameless plug for my article.

https://loadoutroom.com/51926/ultra-sho ... up-part-2/

Be nice to see a follow up to see how it can defeat, or not, Level IIIA body armor. If it doesn't penetrate, or partial, it would be nice to see how much deformation there is. Maybe a top 10 300Blk hunting/SD bullet shootout.

I think I have a couple IIIA plates around that are disposable. Not gonna shoot my III+ plates though. Need more Barnes Black tips, need some more IIIa's and I'll get a video up

I shot Level IIIA soft armor, not plates. I'll have to look to see if we have any Level III plates left. I do have an old, not sure level, door gunner plate, its a full chest size plate, might have to try and punch some holes in it.

[Omega]

Thought I'd share some pics.

This is a panel we tested, 3 strikes 1, 2, and 6. It's been many years so I don't recall distance for this panel, we tested them at 25, 50, and 100 yards. But it's typical of the entire test, a few penetrated while most didn't. Because three seemed to be misses, it was probably at 100 yards, but who knows.


One went through (1 CP), but I found three steel cores, so not sure what went through.


This one shed it's steel penetrator core and mushroomed perfectly (2 CP)


Here are all the captures, two steel penetrator cores slid to the bottom of the panel, another was about 2" low and to the right of the POI (6 CP), two are the pieces of lead core.


This panel had Kevlar layers which feel a bit waxy, I don't think these made the cut since the panels we ended up with don't feel like that, and the new ones are dyneema.

[Ghost12three]

Thought I'd share some pics.

This is a panel we tested, 3 strikes 1, 2, and 6. It's been many years so I don't recall distance for this panel, we tested them at 25, 50, and 100 yards. But it's typical of the entire test, a few penetrated while most didn't. Because three seemed to be misses, it was probably at 100 yards, but who knows.


One went through (1 CP), but I found three steel cores, so not sure what went through.


This one shed it's steel penetrator core and mushroomed perfectly (2 CP)


Here are all the captures, two steel penetrator cores slid to the bottom of the panel, another was about 2" low and to the right of the POI (6 CP), two are the pieces of lead core.


This panel had Kevlar layers which feel a bit waxy, I don't think these made the cut since the panels we ended up with don't feel like that, and the new ones are dyneema.

Thank you for sharing this info, but I'm wondering how close this test compares to supersonic FMJ being fired from 4.5"ish barrel, at very close range (25 yards). Judging by other answes that you guys gave me, I imagine it would penetrate. Were the rounds you used for this test expansive? Were they super or subs? Thanks again, bro!