There are several of us here that have 458's.
Great caliber! It is a Reloader's caliber,and often very hard/expensive to find factory ammo for them. I only handload for mine,and use several different bullets for my loads.
300gr JHP's,300gr Nosler Silvertip's,325gr Hornady Flextip's,350gr Round nose,and 405gr Flatnose.
My main powders are Reloader 7,H110,and Lil Gun.
I use a RRA mid-length upper on mine,some guy's like the carbine length,but I've only had cycling problems with a couple loads,and just changed the powder type to fix those issue's.
It's a great caliber for hunting hog's,deer,etc. in short range situations under 250 yards. It will just flatten whatever your shooting!
Recoil with the 300-350gr bullets is compariable to shooting a 308 rifle,but the 405gr's will let you know about it. Kind of like shooting 3 1/2" mags out of a 12ga.
It can be very accurate,I have several loads that shoot sub-moa,but most will do 1"-1.5" at 100 yards. Plenty accurate for whatever your hunting.