I don't understand why anything heavier than 10.5 grains or so would be too much weight for the gun. 14.3 grains is pretty much a standard weight (in .22) for this nitro piston, so I would think it should handle the same weight in .177 caliber as well. Am I missing something?My concern about going too light is that there wouldn't be enough resistance and I'd end up with too much piston slam.