How many lengths are there ? Iwas thinking 3. Short , long and Magnum. The .270, .280 and 30-06 are on the Long but would they be better built on a slightly longer action for hunting? I have a 6mm and wish it was slightly longer as I do with the Classic swift I have.Are there any things that can be done to utilize these cartridges to their potential[the .220 Swift, the 6MM REm and the .270]