Quoted:
I have some second chance K30 steel plates. they come in a kevlar covering to catch any frag, but their not really supposed to stop anything INFRONT of the plate.
they are to deform and slow the projectile so that the soft armor can deal with it.
its rated for 12ga slugs, 44mag rifle rounds, .30 carbine rounds, and with any kind of distance they are supposed to stop
or "significantly reduce the wounding capacity" of 5.56 and 762x39.
That's a manufacturers claim, not an NIJ armor rating.
NIJ rates armor on it's tested ability.
Until the Zylon debacle no NIJ rated vest had ever failed to stop rounds it was rated to, in the real world.
Safariland IIIA vests of 20+ years ago, stopped 12 ga slugs, and .45-70 rifle bullets, which is far above their rated threat level.
So, I would take the K30 claims with a grain of salt.
––––––––––––––––––––––-ETA K30 label taken from an EE post
The label on the plate reads: Results of extensive ballistic testing indicate this k30 plate, when placed in front of any second chance soft armor, will stop the following rounds of ammunition: 7.62 x 33 Ball (US .30 Carbine) and all other .30 carbine commercial soft point ammunition – 12ga rifled slugs- .44 magnum carbine (18 inch barrel)- 9mm KTW and other 9mm Steel Jacketed Armor Piercing rounds. In some instances, a close range perpendicular impact from any of the above rounds will pass fragments through this insert. These fragments WILL be contained in the second chance ballistic panel behind this k30 insert.
This k30 rigid insert will NOT stop the penetration of the 5.56 and other assault rifle cartridges as the 7.62 x 39 or 5.45 x 39.5 from perpendicular impacts as close range. Under field conditions, however, involving ranges of 200 meters and/or impacts on an oblique angle and/or rounds encountering vegetation or other objects before impact, this k30 insert will possibly stop these rounds, or significantly reduce their wound capacity.
The part in red is worded in such a way that it's impossible to disprove. It also really doesn't make any actual quantifiable performance claims.