Think about it a bit, if the cartridge length is shorter than the trim length, the bullet tip will be inside the case! Looking in my Hornady manual the trim length for the 260 is 2.025. The COL is 2.800! Need to rethink this a bit! Are you saying after firing the case length is 2.013-2.014? Case length and cartridge length are two different things. Probably case length of 2.014 would be fine and as the case is fired and resized it will grow. My thought is probably resizing then firing your blowing out the case walls some and when doing that pulling back the neck a bit. The shoulder will go ahead and fill out the chamber. Just might result in a bit shorter COL! if you take a 260 case and fire it in a 260 chamber, firing will srtetch the case a bit to fill the chamber. Then the neck would get pushed forward and at some point need trimming. Think you'll find that now when you fire these case's again the cace will already fit the chamber much better so rather than pull the neck firing by expanding the case walls, it will push the neck a bit. result is the case will grow a bit!
