I have an addiction to shooting steel with my high powered rifles and my reloads. It started years ago with a .270. I loaded 130 gr. Speer BT with a listed compressed charge of IMR-4350. at 7000' elevation those loads were producing a M.V. of 3250-ish fps. at 200 yds. they would blow through a 1/2" piece of steel plate leaving behind a .50" hole. A friend of mine was impressed but insisted his factory 150 gr. rounds would easily do the same thing. He was quite disapponited to see they would do little more than leave a large crater half way through the plate.
My most recent steel attraction has been with my 7mm rem. mag. loads using 120 gr. anythings, Sierra, Hornady or what ever. At 200 yds. they blow right through. I've always wanted to know what is coming out the other side so I put a 5 gal. container water, the type restaurants get their fryer oil in to see if I could capture the left over frags in the container and was shocked to discover what actually happens. The container had a very large hole on the entry side with a split on the opposit side. In the water was a 1/2" half moon piece of solid steel that weighted 23 grains more than the original 120 gr. bullet, all steel not lead. I couldn't find any lead in the water and no lead at all in the steel plug. I used a tourch and heated the steel plug that came out until it was glowing red, and not one single drop or frag of lead was present. I couldn't even find any copper jacket frags. So I surmised that it is shear pure energy that punches the hole, and the lead and copper jacket probably just vaporizes cause there is no sign of them. I guess it works kind of like a plasma cutter cause the hole looks simular, well you know, it looks just like your piece of steel, except through and through. Those 7 mag. loads are leaving the barrel @ 3500 fps +/- 30 fps.
I tried the same ting with a 100 gr. HP pushing 3700 fps and it wouldn't quite make it through. It did leave a cool looking crater though.
A word of caution though. My neighbor's Son was killed doing the same thing we do using a 30-06 and 165 gr. bullet. His load wasn't producing enough velocity to get through and resulted in steel coming stright back killing him instantly. he was no more than 50 yds. from the plate too. So shooting at long range and using the highest velocity round possible, is probably a must if were going to play around like this.