A rifle with 1 in 28 twist would be about ideal. If you want to shoot a light bullet then go with one of the sabots shooting a 44 or 45 cal bullet in a 50 cal rifle. Keep in mind that a 250 grain bullet would be considerd very light in a 45 cal rifle like the 45-70. The advantage that a 45 cal ML would have would be minimal at normal ML ranges. Don't go with all the hype in the ads as you read they used a 155 grain bullet with 150 grains of powder. Did they happen to tell you how tight the grouping was?