Sometimes I wonder things

Recently I found myself wondering "Will a .308 Winchester pierce 1/4" thick steel at 100 yards?".

I assumed that it would but I didn't know for certain what the outcome would be.

And since I prefer to know rather than assume I grabbed a box of rounds a rifle and a 1/4" thick steel plate.




Then I headed for the hills.

The steel plate was subjected to the following rounds:
.308 Winchester (our official test caliber)
.300 Win Mag
6mm
22 Mag
22 Long Rifle fired from a pistol.

All shots were taken from a range of 100 yards with the steel plate hanging from a tree branch.

Range was verified using a GPS which claimed to have +/-12ft accuracy that day. So lets say the actual range was 100 yards +/-24 feet.

The plate held up great....to the .22 cal rounds. No surprise.

The center fire rifles were a little tougher on the steel:


This is the entry side. Notice how the copper jacket has been stripped off:


And here is the Exit:


It didn't deform or flex the plate at all:


This shows how much expansion there was. The .308 brass can almost pass through the hole:


....now I find myself wondering something again. How much steel would it take to stop a .308 bullet at 100 yards?