While it’s not a 400 yard round, try looking at the Ruger American. I just bought one from a Buds in 7.62x39 for deer hunting in Indiana. They use Ruger Mini 30 mags, are very light weight and ammo is cheap. Around $400 plus scope, I put a Leopold 3x9 on mine, it’s a very good buy. They come in several calibers, but I just like the .30 Russian.