In gamo replay 10 magnum gen 2 are the best pellets. They are at the right fps limit that an air rifle should have and the fact that they are hollow point with the polymer tip makes them stand out. They also have a very good ballistic coefficient, just like the corresponding jsb pellets with dome head. Generally, few spring-gas ram air rifles can support the 5.5 caliber with proper muzzle velocities, for pellets weighing 16 grains or more, we should go exclusively for pcp rifles.