dont be dissapointed... it also needs to take in consideration that all pellets types have different weights, so if you got 100 fps less with a common pellet like the crosman prem, you'll go even slower with a 18 gr or 21 gr pellet... but velocity means absolutely nothing (we should only use it as a a measurement of the health of your spring or seals... (as along as you are getting consistent velocity the rifle is good). what you should do is get lots of different .22s and just shoot for groups. the best group wins... so load up on those pellets and then after that check what velocity they shoot. even if going at say 600 fps as long as they are accurate they will do the job for small game hunting. case in point, i have a .22 that shoots 18.1 gr at 602 fps +_ 4 fps pellets into a 1 inch circle out to 55 yards... with a good scope and some hold over points i have literally tore the head off a squirrel at 52 yards. DOA. great predictable rifle. Dont get sucked into the velocity wars... its all about accuracy.