I have to say this is a bad idea. I have read in several reloading maunals that it is a bad idea, and common sense will tell you to really watch for case head seperation, more than any other wear factor on a case. Try this simple test; strasiten a paper clip, and then at the end, make a bend 90degreees. If you run this feeler up the inside of the case, you will be able to feel a vey thin place right above the case head. The 6.5 jap was supposed to be the strongest military action of ww2. TYPE 38? 7.7 were renown for being some of the weakest. also, gas control from a ruptured case( what is likely to happen with the 30-06 as a parent case) just above the web is not good, like in a maser, springfeild, etc. I assume you are free sane, and over 21, so do what you want, n feel is safe. I wouldn't, and if you were asking me, Which you didn't, I wouldn't do that.
Also, fast burning powder usually used in a cast bullet load makes just as much CHAMBER pressure as a full case of slower burning powder, it just doesn't make the pressure for as long, so even with mild loads, you may be tredding on what little safety threshold there is