I have a couple Enfields I reload for. Looking at the fired cases you’d swear they were not chambered for the same cartridge. My No1Mk3 Indian Grenadier has a tight chamber and excellent bore, while my No4Mk1 blows the shoulder out quite a bit but has an excellent bore too. To extend case life each rifle has its own box of x50 cases and I use a Redding 303 British neck sizer die. I do most of my shooting with the No4Mk1. With the following load (WW case, WLR primer, 39gr of 3031, Hornady 174gr RN) I have to set the rear sight to 300 yards to hit point of aim at 100 yards, but the up side is that using the battle sight I’m dead on at 100 yards. While IMR 3031 is considered a preferred powder for the 303 British, I’ve always thought it a bit on the fast side. After getting great results with Hodgdon’s VARGET in my Mosin Nagant M44 I decided to try Varget in my Enfields. I loaded up rounds, using data from the Hodgdon web sight as follows, (WW case, WLR primer, 40gr Varget, and a Sierra 180gr SP) these should be close to 2400fps. Was going to Angeles Shooting range this weekend to try them out but canceled due to a brush/forest fire in Little Tujunga Canyon where they are located. At some point I’d like to experiment with the lighter 125gr (.310/.311) bullets intended for the 7.62x39 in both my Enfields and Nagant rifles. But with their cost being close to the heavier 150gr and 180gr bullets this may be some time off unless I can find an inexpensive source for the 125gr bullets.
Be safe over there in Dirkadirkastan.