Maybe you are right. But they don't really jam. They put reballs into a washer after every practise. We use silicone spray to make them more slick (don't know if thats the right word ) You get jam maybe once in a game or something like thatdo you not find they jam a lot more frequently than using paintballs? even after cleaning them... :/
But my team always debates which hurts more, i personally think using paint does, just because when the shells break they can pierce skin, which then itches like hell!