Handcannon,
I would also suggest the 250 Imp. for the reasons mentioned above. If you wanted to get the most horsepower from it as possible build it from the 307 Win. case and you will get the benefit of a rim plus a stronger case than the orginal 250 Savage. But using the orginal case is fine too. Also, when considering cartridges like this in the contender you don't want a high polished chamber. This quote from someone I trust says it well concerning chamber polishing:
"You mentioned a "very fine" chamber polish.... I have backed off of finishing with 600 grit paper in the large diameter chambers and stop at 400 grit, leaving a less slick surface for the case to adhere to when it expands, thus making the case take more of the pressure load instead of slipping back will near full force against the breechface."
Hope this doesn't muddy up the water. I have a 250 Imp. in an XP for my boy to use for deer. You won't be able to laod it up to the levels of the XP, but you can still have a great cartridge that works well with the Contender as long as you respect it.
Ernie
