Hello, all of you:

I have in my hands the third edition of Graeme Wright book. I compared the reloading and pressure data for the various 450 3 1/4 cartridges (NE, NFB and BP, pages 209 and 219), based over authentic pressure recordings. My conclusions, or better, what I read, is as follows:

1) The old cordite loads for the 450 NE produced 16-17 tons of pressure.

2) The old black powder loads for the 450 BP produced 11-12 tons, a little less with the NFB loads.

3) You can´t shoot OLD CORDITE 470 NE cartridges in a 450 BP without risking your face (First and evident conclusion).

4) With modern powders like RL15 and RL19 and soft nose bullets, you can duplicate the old cordite ballistics producing a maximum of 12,5 tons

So...(and speaking strictly about the 450 x 3 1/4 case)...

5)With a slow modern powder like RL19, you could shoot 450 NE loads and soft point bullets in a BP rifle without exceeding the proof pressure for black powder...(Second and not so evident conclusion)

Interesting, isn´t it...

Or have I missed something?

Antonio