I'm well aware of what a .308 will do to metal plates. Depending on strength and thickness, and many other variables, it will do anything from bounce off and make a dent, to make a hole, to even shattering the plating.
I've shot quite a few different military weapons (5.56mm, 7.62mm NATO, 7.62 Soviet, .30cal carbine, and many many more including some really high power hunting rifles) at "real targets", from wood frame houses, old vehicles, to even sandbagged bunkers. I'm quite familiar with the effects of weapons on real targets.
For instance a Soviet 7.62mm x 39mm steel core round from my chinese made AK-47, will go all the way thru a VW Minibus from the back and into the engine block, which suprised me considering that it is a relatively low velocity round.
So what was your point?