Thanks Will, I'm still considering my options at the moment.. I like the e idea of brass as I'm already reloading .357 and .44... I was liking the .303 as I believe I can use pistol primers and I could probably make up the tooling for the press.
Although I did watch some diy .410 reloading with sockets and nails etc.. and that too looks like fun for very little upfront spend..

I should probably buy the gun first 🤣🤣