I got a bunch of this Wolf 7.62x39 ammo for a new for me Mini-30. Like 2000 rounds. Well I took it out to the range and only about 25% of the ammo actually shoots the rest of it doesn't work. Anybody know why this happens, it was new when I bought the ammo and its 122 gr hollow point. Never had any kind of ammo do this before and I am kind of ticked because at 25% it now costs the same as remington ammo loaded in brass cases.