We had a discussion a while ago about how bullets pierce armor. I have an interesting new development in that. A friend and I found a bowling pin and have spent the past 2 days shooting at it, with 22, 9mm, 12 gauge shotgun and 223 high powered rifle. The bowling pin is made up of about 2mm thick plastic around a wooden core. The 22, 9mm and 12 gauge just pissed it off, hardly doing any damage at all. Even the 223 high powered rifle didn't do much damage. Of the 4 guns, only the 223 penetrated the plastic shell at all, and even that didn't do as much damage as I had been expecting. I guess MJ was right. If the armor is reinforced from behind, it's much stronger. Otherwise, I'm certain that the 9mm would have gone straight through the 2mm plastic shell. Just thought someone would be interested in that.
The funny thing is that we did more damage to the cinder blocks we were using to hold the bowling pin than we did to the bowling pin. Between the 9mm and the 223, Mike and I shattered 2 cinder blocks down to dust. With the 22 and the 12 gauge, I put a rather large hole in a third. Shooting at a distance of about 50 yards or so.
Cinder blocks have a lot of air inside; they're made to be strong structural supports for loads placed on top of them (the top and bottom being the open sections) while being very light and so adding very little to the load. If you were to put a board on top of a row of cinder blocks and pound on the board with a sledge hammer, you would do very little damage to the block beneath, as they are designed to withstand pressure that is spread across them. They are not designed to withstand focused pressure on individual points, particularly if those points come from the sides or ends.
--M. J. Young
I would like to interject that none of those weapons are particular used as armor piercing weapons. The .223 isn't much more than a .22LR with more powder behind it, and has never been accused of being a high powered rifle. It was meant to wound flesh, and go through light body armor. As for armor piercing bullets, MJ has taken it into account by putting modifiers on attack rolls, for example, for a hollow point bullet, you can put a -10 modifer to hit, and a +10 damage roll modifier, and reverse it for a FMJ bullet. In any case, Multiverse has a lot of rules and rolls, making it more complicated, probably isn't the right direction to go.
Well. considering that the 223 was up against a 22 pistol, and a Hi Point 9mm carbine, it was the most powerful gun there. Now, I'm willing to bet that a 30-06 would have turned the bowling pin into Swiss Cheese.