 It is loaded to slightly lower velocities than the rimless .333 Jeffery, firing the 250-grain bullet at and the 300-grain bullet at .Upon its introduction in 1908, the .333 Jeffery firing the 300 grain bullet quickly developed an excellent reputation due to the very high sectional density and exceptional penetration of the round.Unfortunately the original 250 grain bullet was a copper-capped hollowpoint that was too fragile to be fired at 2,500 feet per second, making it unpopular and marring the .333 Jeffery's reputation for some time.