I got my bone stock SR-556 shooting a .6 MOA group with 26.9 grains of CFE and 55g Zmax's on a grip pod. 26.8 also shot well, but the group exploded in size at 26.7 and under, and was significantly bigger at 27.1. Not that these will be your same numbers, but you'll definitely want to try a few loads with it. I've really liked it so far!