AG42B's are usally fussy about what ammo you use in them. If you reload, this is not a problem, but if your like me and don't (yet), then you have to find a factory round that will shoot well in your particular AG42B. Key is, they usally like fast burning powers.
First ammo I shot in mine was Norma. Too hot. Casings would split, primers would be disloged from cases, cases would come out black and dented.
Then I tried winchester. Still to hot. Not as bad as the Norma stuff, but the cases were still getting banged up, the rifle rattled violently when fired, and accuracy was the pits.
Then I tried Bell 139gr SP's. PERFECT. Smooth loading/fireing and excentlent accuracy. It also shoots Milsurp well...when I can find it. I got a box of S&B Rounds I want to try too...if I ever get around to it, I hope they work as good as Bell....or better.
BTW, just because Norma & Winchester ammo dosen't work in my ag42B, dosen' mean it won't for all. Each rifle is different when it comes to ammo. I've known AG42B owners that shoot Norma and/or Winchester well, and ones who thik Bell is the pits.
Go figure.