I normally use US ammo, Federal first and Rem/Win next. I was at Academy and they were out of Federal but they had cheap Monarch from Serbia. I figured a couple of boxes to waste at the range would be fine. BIG mistake. I dont know what was wrong but it wouldnt feed, it would hang up on ejection, and just felt bad. I thought it was dry so I Rem Oiled the works, but no use. I quit after 15. I thought I had ruined my rifle but fortunately I had some Federals in my box. I ran a few of those through and they were perfect and smooth. I use Serbian In my Mosin and it runs fine, but never again for .30-30.