1cc=1ml I usually dont switch needles cause it doesnt make that big a difference, as far as losing that .3 of a cc you will lose that anyway. stick that needle all the way in you want to make sure it is deep in the muscle or you can waist even more by it leaking out the injection site. The injection is not painfull all you will feel is th needle break the skin after that it will just slide right in no problem, trust me dude it does not hurt, just the pinch when the needle first penetrates the skin. good luck bro