190 gr SMK or Nosler Custom Competition.
IMR 4350, IMR 7828, or IMR 4381. H1000 would be the slowest powder I would consider for that range.
Although at 700 and under, you could get away with cheap 168gr HPBT bullets and be just fine, no issues with the transonic range, but you will want 190's if you get out beyond 1k.
Machine guns are awesome until you have to carry one.