1/4" is for rimfire and pretty distant centerfire stuff.
Not very well suited for repeated 30 cal hits at 300-500 yards.
Just one mans opinion, but I'd spend a few extra for 3/8" if 500 is where you plan on stopping.
Yup. You want 3/8" AR500 for that application, IME. The 1/4" thick stuff will work, but it'll cup pretty bad with extended use.
