I have a 16ga sxs / 7.7 mm rifle made by Miller & Val. I want to know what cartridge this takes and need help. The stamping on the rifle bbl indicates 7.7 mm, and in another place 2,5 g GDP (could be 2.5), but doesn't seem to indicate the length of cartridge, e.g. like 8/74. Looking into the chamber there doesn't appear to be much "necking down". Otherwise, I haven't done a mold or measured anything yet.
Is anyone familiar with what size of cartridge this gun might use and where I can find them if this is an "odd-ball" cartridge?
Thanks/G
