Re: getting into 50 bmg
I am not familiar with the Noreen, but will look into it.
Unless you are trying to shoot 1000+ yards surplus ammo will do just fine for "shooting things"
I have shoot surplus ammo from around the world. Argentina, Korea, Isreal, Russia and have not experience a hang fire with any of it. I have shot all the tracers, red, yellow and brown with no issues.
At $2400 what kind of accuracy are you looking for? What is the noreen designed to do < 2 MOA? I shoot two Barretts and a Macmillian, and not all 50 BMGs like the A-max. You will just have to find out what yours likes best unless you want to reload it yourself.