I use the SPEER 100 grain spitzer over 45 grains of IMR 4350 powder, seated out as long as will function in my BLRs magazine. I tried several of the 120 grain loads but they tended to seat the bullets very deeply into the case and the velocity was lower than I expected, and acuracy was very inconsistant, which if found surprizing because the 117 grain round nose bullets by HORNADY and NOSLER 115 grain spitzer partition bullets did much better. of all my loads the nosler partition 115 grain over 43 grains of IMR 4831 proved to work best on large mule deer but I use the 100 grain SPEER bullets far more often as they are much cheaper, and slightly more accurate. since I only use the 257 rbrts BLR on deer the differance in penetration is of no practical importance