I buy my steel targets from the scrap bins at a steel fabrication plant at a nearby city and I pay by the pound. This is mild steel.
1/4 inch would look like Swiss cheese after just a few hits. Almost all my rifles will penetrate 3/8 inch walls of sectioned gas cylinders at 300. These things are huge and are not much of a challenge. My tiny .204R and .20 Practical don't penetrate 3/8 but just about everything else does. The ace penetrator at 300 yards is a 6.5-06 using 100 grain Barnes tipped triple shocks at 3350 fps mv.
Daylight can be seen through 5/8 to 3/4 inch thick mild steel targets after a month of shooting..
The long lasting targets are solid cylinders about the size of a 8 ounce pop can and these get so chewed up the sharp crater edges make them real uncomfortable to handle. Mrs. Ducks (new 20X scope on .243) and I have shooting contests with these tiny cylinders at ranges up to 500 meters.
Be safe when shooting at steel - bullet fragments can come back at the shooter and sparks can set the woods, grass and whatever on fire.
The photo is a 6mm Ackley with 105 grain Amax bullets at 3150 or so and this makes a good size crater (fat pop can @ 300) but the 100 grain 6.5-06 Barnes bullet does more. Velocities at 300 are about the same but the Ackley is faster at 500 meters.
Paper targets are dull and uneventful.
Mrs. Ducks put the 3 shot cluster on the bottom of the target with her Lilja barreled .243, the big Ackley did not do as well. Same 105 Amax but at 2950 some 200 fps slower than the AI.
Edited by Stevey Ducks - February/09/2016 at 23:34