I have a 1903 by Army and Navy that shoots pretty well, but has a faded and heavily worn bore. The groove diameter is approximately .268; I haven't measured the bore, but I assume it is around .262 or so. Anyhow, I am thinking about re-boring and rifling to .277, and make a 6.8/6.5x54 wildcat. This would be somewhat similar to the 6.8 Chinese cartridge, but based on a smaller diameter case.

The object of this exercise is to (hopefully) achieve a cartridge that will feed without magazine modifications. Any suggestions?