Lee Enfield No 1. Barrel

[BVZ24]

My original thought was 'What safe, cheap, easy to find 30 caliber cartridge can I use to make a fun plinker rifle I can shoot all the time?'

The answer to that is 7.62x39. It requires some engineering, but it's doable and I could probably reverse engineer one of the Australian conversions to a degree.

But the primary issue with that is I can't find anyone US who would make .312 barrel in the first place, which kills both 7.62x39 and a full length 303 build.

My new question is more of a 'What bore can I get a 30 inch barrel in?'

I'd still like to stay close to the original concept, and it seems like the closest I can get is 30-30, or a .308 that's only safe if I'm there. But for the record, I'd still prefer the original 303.