Michael - thanks for the offer, I have a few .405 cases left over from another project that I was going to cobble up if the Bertrams proved iffy. We'll see.
Don - yes it's a 26" octagonal barrel. I'll post a picture or two when I find my camera again...
SKB - that's certainly not good news about bullet failure on game, 'specially with a .360 BPE which is not a barn burner in the velocity department either. The ones I tried were also .025 jackets and light weight at 235 grains but I had figured to go for .030 jackets and either 270 or 300 grain for hunting. I will definitely test them first now. Thanks for the heads up!