I purchased a No4 Mk II some years ago, along with about 2000 rounds of Radway MkVII ball. After shooting this stuff for a while, and cleaning my rifle for corrosive ammunition, I decided to start reloading. This was actually the first cartridge that I ever reloaded for, with the exception of loading shotgun trap loads.
My introduction to loading 303 brit was a lee loader, 100 NEW pieces of Norma brass, a lyman mold and numerous conversations with older gentlemen with have been in the hobby longer than I had been alive at the time. I decided to work up a load using IMR 3031. The only guy I knew who loaded anything in 303 brit was using cast loads with a gas-check, and liked this combination, was fanatical about it. And it worked for him;the trophy bucks he has taken with it attest to this.
Well, now I'm all grown up, and have a nice bench with a progressive press or two, some single stages, um, ok, I've got a big bench.. and all the goodies that I ever wanted and still keep buying stuff to tinker with. Guess what? I still use that Lee Loader for 303.
In my No4 MKII, I'm finding that it enjoys a steady diet of 150 Grain Hornady spitzers and 42 grains of Hodgdon H380 give me excellent accuracy. It's not a max load. There are no pressure problems. I use Remington 9 1/2 large rifle primers.
I really like the Hornady bullet for two reasons. First, it shoots great. I've shot everything from cast loads to pulled 7.7 jap hotchkiss semi-rimmed (205gr, at one time, you could buy these feeder trays for next to nothing. They might be more now, I have no idea!) to heavy Woodleigh Weld-Cores, with different powders. The 150 gr Hornady gave me consistently good accuracy, especially when I only neck re-size. I only full length resize brass that I get from other people that get left at the range.
Second, that cannelure insures me that I have the correct seating depth. I OAL measure every cartridge that I load.
Also, with this load combo, I RARELY ever trim brass.
I don't prime with the Lee Loader.. I use an Autoprime. I guess I like the Lee Loader because as when I load anything I take my time and sit quietly with no distractions, and really enjoy myself, knowing that each round will be true. I guess it's like getting out that Daisy Red Ryder and plinking cans off the fence.. I'll just never outgrow it!
Anyone else reloading for 303 Brit? I've kept a journal of all my loads in a notebook, along with range reports and photographs. Please share your knowledge!