+1 on the 500S&W being one of my least accurate Handis, best I've been able to do is ~2" at 100yds with a scope, but it's pretty consistent with all of the bullets I've used, 350gr and 385gr jacketed, as well as 440gr, and 700gr cast, 2" is plenty accurate for its intended purpose and range tho.
The most consistently accurate of all H&R chamberings I own would be the 30-30 and 25-06, both shoot consistently under 1" 100yd groups with all loads I've shot, factory or handloads. Runners up are all 45-70s of course, 223, 243, 280 and 30-06 for me.
Tim