Back to the 'steel bedding block' point of the OP, this morning I spent Labor Day Laboring Away at making a steel stock liner fit my receiver legs. Not too hard, since the stock liner is soft steel. Squash each set of legs on the liner to be too tight for it's particular receiver leg, then file to get a good snug fit- the receiver legs are at a 3° taper. Get them to fit snug without the receiver legs bottoming in the liner 'slots'. Then, bend the skinny straps of the liner to get the two sets to line up as a unit.
My plan is to bed the top of the receiver to suit the draw etc at the front ferrule, then install the liner, later the trigger group. I'll probably need to slot the liner screw holes in the stock, use temporary screws during the bedding, then later make holes to suit bedding the screws to the liner.
I'm thinking the bedding's tasks can be broken down to :
1: Fore and aft recoil stability, taken care of by the liner legs.receiver legs interface.
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2: Up/down and front draw, taken care of by the top surface.
3: Clamping pressure, done by setting the rigger group at the appropriate distance below the top.
4: Left/right yaw is taken up by the legs.
5: Left/right motion will be taken care of by the legs the bedding compound outside of the receiver legs, between legs and stock.
My bedding won't be handling the sliding of receiver removal, so I'm thinking something brown will be adequate, and less visible, rather than the Titanium stuff. As a woodworker, I learned to mix walnut sawdust into clear epoxy to make epoxy putty that matched. Hmmm, it would be softer than Brownells, but still harder than the wood stock. Hmmmm.... Or, I wonder if Home Depot sells cement tints, like carbon black, or Iron Oxide, or .... using it as filler would make my syringe of epoxy hard as concrete...
Now I just need a clunker stock to practice on. If you need me, I'll be waiting on he curb for the postman.