easy to over do it, yes. Kinda defeating the purpose of case life.
When setting up the FL die for zero shoulder bump some cam over may be necessary to avoid extruding (lengthening) the case.
Sorry for the confusion. I'll try to clarify.K22:
Can you clarify what you're saying here? My take is that if you have the press and die set to cam over, you've got the die as low as it can go, thus bumping the shoulder to the max amount possible, and also sizing the body to the max amount (which will correspondingly lengthen the case.) I'm assuming we have differing definitions of "cam over".
Sorry for the confusion. I'll try to clarify.
Cam over means that the ram is firmly contacting the shell holder with some resistance. Depending on the amount the die is turned down on the shell holder, the degree of cam over (resistance) can vary from slight to medium to heavy. The degree of cam over needed to produce the desired sizing can vary from press to press due to variation of play in the press, vary from lot / brand of cases, number of times the case is work hardened, and of course the specific rifle chamber.
So if one desires to size new cases without setting the shoulder back then the die is adjusted to just contact the shoulder thus preventing the case from lengthening.
I'm regret to say that were are going in circles here. This is not a complicated process or issue. Please don't take this as a criticism but merely an attempt to offer assistance if you need or want it.The problem with body dies and standard full length dies is that the body squeeze and shoulder bump are fixed, with no way to adjust the relationship. If you need, for instance, a larger amount of shoulder movement, you're going to have more body squeeze as well. If you need to size the body more, you have no choice but to push the shoulder back more. The only viable alternative is to use a different die.