It is definitely not a 9.3 X 72. After the fine gunsmith informed me, I bought a box of cartridges and they didn't even come close to fitting. I was in my 20's and he had kind of a "don't bother me, boy" attitude. It does have the Rigby style forend latch. The serial or assembly number is in the high 1200 range. I thought with hammers and an underlever action the gun might predate 1910.