Not sure the 52 chambers it....but i know "cooper" chambers it. haven't compared the details.....but i assume they make a model you'd like that would chamber it....maybe not.

as far as twist rates, I'm unsure....the target/reloading guys might know more.....

looks like if you wanted to shoot up to 160grs you want a 1:8
if 140grs....1:9
120grs....1:10


they also list a 85gr at 1:12, so wow 85grs up to 160grs....
http://www.riflebarrels.com/products/caliber_twist_rates.htm

if I had one I think I'd stick to 120-160grs....so probably get an 8 or 9 twist....probably an 8 since from what I know is its easier to go light than to go heavy....

Looks like the "Jackson Game" doesn't come in it....but similar rifle would be the "western classic" or "custom classic" or "classic" or geez, looks like a bunch of others come in it....i think every rifle cept the jackson game.....

don't let me talk you into anythign though, just thought it may be a cartridge to consider.....

I think the model 52 vs 22 only depends on what they chamber in each...52 seems like standard cartridges....ie 30-06 based.....

btw what are your plans for this rifle? targets? antelope/deer? elk? etc...? long range?

I know some guys on here have 6.5-284.....seen a few pictures, target rifles etc....i believe its one of the goto's for 1000yd competition.....