y'all gonna think this is a dumb question (is it obvious that i am a little embarrassed to be asking?)but there seems to be 2 sizes of grease fittings...one is small and my grease gun handles it just fine. But theres a bigger size one that my grease gun doesn't fit. do i have to buy a different nozzle and if so why can't I find it anywhere? i have a cheapo hand crank gun that i put the bigger size cartridge in.