>>64231703
>3. Soft armor is extremely ineffective by itself against rifle rounds. M193 can clear more than 150 layers of kevlar (a classic IIIA vest is 35) and still kill just fine. Use the plate to shatter projectiles first.
I found one experiment where 50 mm or 96 layers of laminated kevlar (impractically thick for infantry) will stop 7.62x51 9.7g at 857m/s lead core round. The author of experiment also noted a 25mm thick MAS (multilayered armor system) which composed of ceramic front layer, kevlar mid layer and aluminum backer combo would also stop the same round.

>>64231363
Kevlar cant really stop high velocity rifle rounds so you gotta put something rifle rated infront of it.

https://youtu.be/uDvdcZO1nkM?t=445
According to this 45 layers of kevlar can stop (but fail lvl3A standards anyway) m193 out of 16 inch barrel.

https://www.youtube.com/watch?v=wM0SpYfOCJ8
This guy shot 5.56 and 7.62 rifle rounds at the muzzle (with no barrel length specified so the test is kinda bad) into level 3A panels and penetrated depending on round 4 or 6 panels.

https://youtu.be/zErupXARACI?t=339
This guy shot 5.56 from a 16inch barrel and penetrated 4 layers of lvl3a panels with the round getting stopped in the 1th lvl2A soft armor. 7.62x39 FMJ stopped on the 2nd lvl2a soft armor.

https://youtu.be/NBjWj2ik51I?t=212
Oxide tested lvl3a soft armor panel from safe vest at 550 meters (600 yards) with 3 shots of 5.56 m855 from a 18inch rifle. All 3 rounds penetrated