Some time ago I mentioned a problem I had with my 5.6 x 50R BSA Martini with the cases not wanting to eject using RWS cases whilst other brands would.
The difference being the base size of the case.
Because these cases are hard to get I very carefully hand filed the base down and they now eject ok.
At the range to sight in a vintage scope I was lucky to find in perfect untouched new condition for aother BSA Martini in 223 I found three quarters of these 223 cases failed to extract and had to be knocked out with a cleaning rod.
Measuring the base of the cases I found the same problem I had with my 5.6 x 50R
I always full length resize my cases for Martini's to make them the same size as a fired case.
Well didn't bother altering these cases as they are cheap as chips and easy to find but did check my other different brands of cases to check the size of the base of the case.