Some progress to report and a question.

I'm on hold with my load development for the 500 BPE Woodward, and dies arrived for this rifle in 9.3x72r from Buffalo Arms, so I tried resizing a case. That by itself didn't help. Then I wrapped the case in a layer of Scotch tape where the Sharpie test showed it was rubbing. Applied Imperial Sizing Wax and ran it through the die, with the decapper removed. Cleaned that tape off and applied another band lower, closer to the rim.

And now it fits! My thought is to do this to 20 rounds, load and go see how it shoots. The question comes about the loaded ammo I have from S&B. Can rounds be detonated by trying this with tape drill with a loaded round? There's nothing contacting the primer and there has to be some space in the case for the powder to move. (I don't have a bullet puller, which is why I'm asking.)

Pictures show the resized with tape case fitting flush with the barrel face vs an untouched RWS case, plus the two cases outside the gun.

Taped & Sized case on left

Taped & Sized case on right