Remington40x:
I have owned such a rifle for many years, and use it with the the little 8mm Nambu pistol bullet for plinking (either 95 or 102 grains, my memory fails me, haven't loaded it for a while since my youngest left home!). The Nambu bullet is made by Taipan in Australia. For more serious stuff, I use 150gr 8mm rifle bullets reduced a few thou by pushing them through a die, and drive them fast, the Cadet action can take it! I don't have access to my notebooks at the moment, but they are all Aussie ADI powders, mainly AR2206 I think.
You are quite right about the twist rate of course, my rifle shoots .32-40 factory-equivalent loads (165gr bullet) quite well at 50 metres, but is starting to key-hole by 100 metres with attendant loss of accuracy.
