Almost forgot. DO NOT, DO NOT, DO NOT shoot API rounds at anything hard under 100yds. I know this might seem like a no brainer but my buddy wanted a hole punched in a 8"x4" piece of steel he had sitting around, just to put on his wall.
I had a little trouble hitting it at 200yds and we were running out of daylight so we moved closer to 40yds, bad idea. I fired and after the shot broke we heard a "thud" behind us. Turns out the steel penetrator had sailed through the steel but the copper jacket had peeled off and gone in the opposite direction, back towards us. Luckily it had bounced harmlessly off of a barn door about 75 yards behind us. Luck was on our side that day, had the angle been any different it could have come back and would most certainly have killed or seriously injured one of us.