Have used over twenty new boxes of Prvi .303.
It is the only ammo I reload (30-06 is next), and have used PP cases at least four-five times with no signs of anything abnormal.
Very experienced reloaders claim that Prvi brass is thicker and lasts longer than Remington.
Iron Mike: If you have Enfields with 2-groove bores, you might be aware that some have serious issues with boat tail (BT) bullets?
"Ammo seek" appears to have only one seller with bullets which are Not (SPBT) Boat Tail.
One of my 2-groove rifles (LB) makes nasty keyholes from 100 yards, and the other (British) does not, with the same box of ammo.
Both bores are in basically identical condition. The LB has a little bit of extremely tiny specks in or by the grooves in the last part of the bore, and these very tiny specks are very difficult to notice, except with the bore light.