There was a 380 x 2 1/4"
cartridge
Eley loaded it for Rigby and the National Arms & Ammunition Co also loaded it

the Rigby load was 60 gr Blk 160 lead paper patched round nose hollow point
N A & A Co " " 55 " " 180 " " " " " "

origin pre 1883

Reference British sporting rifle cartridges Bill Fleming
" " Birmingham cartridge manufacturers Bill Harding

I hope this helps

sbs470