newmexkid,
No apologies needed, and I was just having some fun with it anyway. No, the pressure changes from this single factor alone shouldn't be anything to worry about. You mention using partially sized cases in two different rifles, though, and I can assure that's going to cause trouble down the road. Probably exactly the sort I was joking about. Please, if you're loading ammunition that will be used in multiple guns, always go to a complete F/L sizing. No neck sizing, no partial sizing. Full length size and be done with it. Even at that, you need to understand that conventional F/L dies don't size cases back to their original unfired dimensions, and you can still run into chambering problems if the ammo is used indiscriminately in several different rifles. Keeping the ammo segregated, by gun, is the best way to go. Not always possible, but it's the ideal solution. I myself load many thousands of rounds of match ammo every year that has to work in any of my Service Rifles. No possible way I can segregate them, since they may wind up beind used in either my primary rifle or one of the back up guns, and they have to function flawlessly in all.