Tight crimp and solid compression (not necessarily excessive) seem to be the answer with straight-wall cases.

I use dacron, it works beautifully, and I don't ever feel the need to apologize for the ejecta.

Horsedoc-
I just looked at the cabelas photos.
Your rifle is a 75gr Cordite/650gr bullet rifle (!!!).
Whoah nelly!
That's a barn-burner for sure.
Do you have a copy of Wright's book?

Cheers
Tinker