I thought you get at least 4 in your magazine Buckstix; & yes some rather substantial rifles have been made of the old P14 / M17 actions,
I'm not a fan of muzzle brakes, but you are right they certainly do work!
To have a session with one of these & shoot as good as that without ill effects speaks volumes; I hope you had hearing protection on to counter that muzzle blast - would have been horrendous!
Good pick up