I am sorry, but this is a stupid idea..
How do you hope to get any accuracy if the bullets are falling out of the cases, or bullets not contacting the groves. Not to mention the blowby you will get.
Get a 308 to load 308 bullets. If you are going to predator hunt in Canada, then get a 243,223, 22-250 or something like it. I would hate to blow out a $100 pelt with a 308. Shoot 10 coyotes and you would pay for any new predator caliber you pick.
