A 150-grain bullet in the 2400-2600 FPS range (muzzzle velocity) would work OK for deer at ranges up to 200 yards, and won't kick too much. There is no powder that is ideal for use in the .308 and is also useful to any degree in the .300 Win. Mag!! The .300 Win. Mag has so much more case capacity that it requires much slower powders than those which are best suited to the .308. You COULD use a powder like 4064 or 4895 in the magnum case, but the maximum charges of powders with this burning rate would give very low loading densities, and hence, poor uniformity of ballistic performance. IMR 7828, H4831, Norma MRP, H1000, or similar powders are best for the .300 Win. Mag., but a bit slow for the .308 Win.

Keep yore powder dry!!