Grizzly,

I would forget all of those and make up and learn to
use a standing rest which does almost a good a job
(in terms of steadiness)
and allows you to recoil back correctly.

A standing rest needs somewhere for you to support you
left forearm (which is holding the barrel) and I would also
suggest for stability to have something for your stomach to push
against and also something for your LEFT thigh to rest against.

And have a look at a Limbsaver pad put on the gun or get
one of the new Limbsaver Should Pads.
They reduce felt recoil alot on the big bores.

500 Nitro