What factors effect brass life?

Do you use a set amount of reloads per case, or do you vary it depending on pressure or what the individual case looks like?

I would think a .38 Special case will last much longer than a SuperMagnumWeatherby, but I only have limited reloading expirience in two cases (.243 and 8x57).

Over working the brass is the killer. This comes in two varieties. First is the big, generous chamber cut by the factory. They have to be in order to accomodate every brand of ammo sold for the cartridge. The brass expands quite a bit when fired. Second is when you got to reload it, and you size it back down, and possibly size it too far. All that expanding and resizing takes it's toll.

If you had a tight, match grade chamber specific for the brass you use (like Lapua), you can shoot it many times, only resize it the minimum amount. The brass doesn't expand because there isn't clearance for it to. And you don't over-resize it. A PPC can be reloaded 50 times or more in a bench gun, if done right.

I started off loading for a pushfeed .243, and always full length sizing. At the time I didn't even know what neck sizing was.

I guess I could switch to just neck sizing to extend brass life?

Does push feed vs CRF even matter when it comes to neck sizing vs full length? For dangerous game I guess you would always full length size, but for varmints or deer it doesn't seem neccessary. Or is it?