My old Speer #11 lists 5.5-6.0 grs. Bullseye under a lead semi-wadcutter for 851-916fps. You'll get a bit more speed out of your rifle but it should still be a reasonably light load and let you use the powder you already have. As has been noted, Bullseye requires care to avoid double charges, but this doesn't mean it isn't a great powder. Just be careful.

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USAF, 69-92
Vietnam, 72-73