I've been looking into this caliber.. What do I need to know?

It's more capable than most shooters are.  But it's not a precision round by any means.

Big, mean, heavy, thumper. Shorter range heavy hitter but not a target rifle.Don't get me wrong it's not a shotgun, but it's not sub-moa.Perfect hog-gun, shit-load of different bullets and loads, fun as hell.

Bench rest accuracy, no, but if one works on their load and takes care you can ge a MOA load, but usually you are looking at 1.5-2 MOA with most untuned loads.  I have gotten tuned loads to go MOA in all of my .458s that I have really tried, both .375S, the .400 and .358 SOCOMS, but with the 7 .458s I'd rather have one load that shoots 1.5-2 MOA rather than 7 different loads that shoot MOA.  The .458 is a 200 yard at best rifle with 150 being more realistic with most bullets, and it is a real hammer within its range, but it was never intended or will be a 500 yard 1/2 MOA shooter.

The most important thing you need to know is to go over to the .458 SOCOM Forums and do some reading.  I'd wager all your questions and many you don't know you have yet will be answered there.

Fired a few today for function check. It's a brisk cartridge out of a 6 pound 1.75 ounce rifle.

This is a three shot group I fired at 230 yards when tweaking bullet drop to match the scope reticule
300 Barnes TTSX with Reloader 7 powder

Exactly what I needed to know. Thanks

Mine is fairly accurate.   It does give me a somewhat false sense of accuracy because the holes are so large that it gives the impression the  groups are better than they actually are.   When you measure CTC  the groups tend to lose their awesomeness.

It's a BIG BORE... "close enough" will get it done...

mine will do this at 100 yds quite frequently .

Wow.  Real nice.

I'd say mine is fairly accurate. This was at 100 yds