I have had the best results with IMR 7828 with 160 grain bullets for full power loads in the 7mm RM. The velocity standard deviation was consistently the best over a normal range of temperatures (low 30's to mid 80's). Lighter bullets have had better results with 4831.

My notes indicate a wide range of results with different rifles chambered in 7mm RM. I don't know what it is, but rifles chambered for this cartridge have produced more variation in velocity (from rifle to rifle) than any other that has been fired over my chronograph.