Don't know if these here'd perform any better than some of the older ones, but the older 130S/135-Carnivores usually only shot 44.75 grain JSBs at around 500fps, instead of proclaimed and advertised 600, which resulted in the loss of 5-6 Joules of muzzle energy; From 46-down to 40, or even 38 in some instances. Aside from the 44.75 gr. JSBs, the only other lightest .30 cal projectiles aren't even pellets at all, but instead FX hybrid slugs, that come in at 39.5 grains; Now these would probably shoot at some 600 fps, as advertised, but are almost impossible to come by - at least in my experience.