Skeeter - Factories do not use powder that you would be able to buy. They buy in very large quantities and the powder is blended to produce the velocities and pressures they are working toward.
I assume you are interested in duplicating the factory load because it shoots so well. What you will need to do is first chronograph the factory load to see what the actual velocity is in your rifle. It may be quite a bit different than what is advertised. Then you would have to work up a load that duplicates that velocity. I would guess that a powder similar to H4350 or H4831 is what you would have to try, to start.
If you do not do a lot of handloading you might be better off just buying several boxes of factory loads for hunting and using handloads for plinking and other shooting.
[ 09-06-2004: Message edited by: Cheechako ]
[ 09-06-2004: Message edited by: Cheechako ]