Gaz52 wrote:Anneal your brass and fireform them . Dont full lenth resize ,a Lee collet die works for me with my Martini Enfield . I have got 6+ reloads with crappy Rem brass and trailboss loads , PPU brass is the best i have found for .303 and my k hornet.
Gaz is on track, I have a few .303 martinis and they all have sloppy chambers(for easy extraction under adverse conditions). The military never intended to reload the brass and it was thick to avoid separations. Also remember that the original load for these was only doing 1850fps which is very mild on cases.
The primer piercing is a bit of a worry but many winchester primers seem to do that at the moment, the firing pin needs to be checked for protrusion and a proper fit in the breech block, some were sleeved for .303 use, some were new and if someone has substituted an original .450/577 block without sleeving then pierced primers and junk through the action are an immediate result. Sometimes the pin has sharp bits on it from wear and these can be smoothed.
Once you fire a round it is fireformed to the chamber and should only be necksized from then on and it will be a perfect fit.
Get a smith to check pin protrusion, breechblock fit and condition. It is worth the money to know it is safe to fire. If he can't disasemble the rifle he doesn't know what he is looking at, many don't.
You CANNOT check headspace on a martini with feeler guages, it is a dangerous practice.
There are people on this thread that have no idea and shouldn't be posting. It is simple, if you don't have personal experience don't comment.
Martinis don't vent well despite being a very strong action, wear safety glasses.