HuntinFool:
I'm using 48.2gr RE22 with a Federal 210M primer and a Lapua case. Remember, my 22-243AI would have slightly greater case capacity than the 22-243 Middlestead.
Norhman:
The McMillan Hunter BR stock worked quite well for me. It rides the bags nicely when working up loads and the forearm is narrow enough to use with a bi-pod when afield.
I put a Shehane Trakker stock, with a 3" wide forearm, on my newest varmint rig in 6.5x284. It really is a bit much for varminting, even from the portable bench. Shehane does have a narrower model, I probably should have taken it instead.