Re: toscrap steel
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: mm509</div><div class="ubbcode-body">With rimfire (.22lr and smaller) you can shoot at any type of ferrous (iron based) material. If you ever plan on shooting at the plates with a .22 mag or .17 hmr, you will want a T1 grade at a minimum...</div></div>
^^^This is correct.
Grade A36 or A572-50 will be fine for 22LR. I would think they would also be just fine for 22MAG, but I've never shot a 22MAG at mild steel plate.
If you want to try and see if it will work, find a steel fabrication plant in your local area. You can find them on the AISC's website. They have a search engine where you can search by zip code and radius.
We have dumpsters full of scrap plate and flat bar of all sizes that we donate to schools and people for odds and ends stuff. It's just going to be scrapped if no one gets it....and scrap isn't worth that much in the scheme of things. Mild steel only runs about $0.42 per lb depending on thickness.....so it isn't expensive. Scrap value is probably $0.12 or $0.14 per lb, so the fabricator you get it from wouldn't be losing much revenue. I can't imagine you needing anything thicker than 3/8 for 22LR....probably 1/4 or 5/16.
That being said, if you shoot any type of centerfire cartridge at it, it will go right through it. If there is a chance of you shooting at it with something bigger, just buy some of the small AR500 targets everyone sells around here. I can tell you as someone in the steel industry that most of these guys aren't making much profit off these targets as AR500 plate is considerably more expensive than mild steel.