Hi, Sarg.

I found out what I needed to know. I am working up some loads for my Ruger single shot in .375 NE. I plan to load to the 40-42,000 psi level. The case capacity of the .375 NE 2-1/2" and the .375 JDJ are the same to within half a grain of water. That's close enough. There is a lot of JDJ data available. I will use the JDJ loading data as a baseline. I emphasize, these loads will be for my Ruger No.3 and will not be for use in any of the old rifles.

I have also commissioned a special run of 320gr .375 caliber RN bullets with thin jackets and cannelures. The bullets should be suitable for game use at .375 NE velocities. The 320gr was an original bullet for some of the old rifles but I couldn't find these bullets anywhere.

Yes, I the shoot the .405 Grenadier. I planned to shoot 400gr bullets in it but they worked out to be on the long side and go deep into the case when I keep the OAL adequate for my Marlin 1895. I am in the process of soliciting quotes to rebarrel a Mosin-Nagant in the .405 Grenadier. There is adequate room in the M-N action for the 400gr bullets seated to a reasonable depth. It has been a slow project interrupted with a couple of personal "events". But I am getting back into it gradually. Standby.