I would check the maximum load specifed by your rifle manufacturer. Finer granulations are more powerful than the coarser grades. Do not exceed what the rifle is rated for. If for example your rifle is rated for 100 grains of 2F, it will be over charged with 100 grains of 3F. Usually you need to cut the load back by around 15% with 3F powder to get an equivalent charge to 2F when using real black powder, find out if that rule applies to Triple 7 as well, I'm pretty sure it would.