I have the 308 X 444 cartridge in a T/C Contender. I feel that this is at the top end of the Contender compatible cartridges but with the right loading it gives excellent accuracy and easily out performs the 30-30 Winchester. My version is reloaded using small base 308 Winchester dies and it does have a longer neck than most.
In the T/C Encore and Prohunter firearms the 30-06 Improved dies can be used to make a more powerful cartridge by fireforming to have a larger body with less taper and shorter neck.
The principle advantage of using these instead of the JDJ versions is that the reloading dies are available as standard dies thus the cost of custom dies are avoided. Other advantages proported to be gained by all versions is the addition of a rimmed cartridge which is supposed to be easier to extract in single shot rifles, the availability of good brass capable of high intensity loads, and the realignment of chambers, throats, etc in barrels with misaligned or "out of alignment" chambers. In both of my barrels re-chambered for 444 based cartridges, these issues have been corrected and I am very happy with both.
