What sources have you used for non-standard chamberings...?
I am still considering the .32-20, as I've heard some in the silhouette crowd load 160-200 grain bullets in them, but there isn't much info out there, and I'd assume that I'd have to cut a custom throat in the barrel to handle the long bullets.
After thinking it over, the .338 Spectre seems a better choice - better bullets, a bit more room in the case, and the option to later get an AR-15 upper using the round. Plus, I'd avoid the issue of having to keep separate 'regular' .32-20 loads vs. 'special' subsonic ones (though I doubt even 'hot' .32-20 loads would harm the suppressor I'm considering).
I can't think of ANY good reason I need to have a heavy/subsonic Contender setup, but like COSteve said in his thread - it's a sickness, and there is no rational thought...
I also thought about the same concept only in an Encore rifle-length barrel.
So far, to keep things simple, I use my Contender frame for ALL pistol-length barrels, and my Encore frame for ALL rifle-length barrels.
