The 8.75 twist should stabilize anything you want to shoot. Getting the heavies to expand is going to be a function of bullet construction and velocity. A 20" tube will give you some muzzle blast, not over the top but noticeable. Felt recoil is primarily going to depend on rifle weight, bullet weight and velocity, You do not indicate what game you intend to hunt with the rifle. If you are primarily hunting deer then 140s or 150s will be adequate.
