You really can't shoot rifles that close without eating some fragments and really being risky. If you need to do it that close for some type of training or something, use frangible ammo. If you want that rifle feel and the ability to safely shoot your steel targets close get a pistol caliber carbine.S
So would i need ar550 or 5/8". Sorry this is all new to me and I'm trying to keep the cost of my purchases below the wifes radar.