Like LaOtto, I inserted a single shot follower into my Stevens 200 in .308. It would feed the Nosler reload's I worked up just fine, but when I changed to Berger bullets and loaded 'em "way out there" the tip of the bullet would touch the front of the mag and feeding became a hit or miss proposition. So, my 200 is now a single shot. No big deal as I like T\C's anyway.
But, this may help you...or it may not. And you may want to ask your gunsmith first. Anyway, I had one of my mag's on my Springfield 1911 give me some feeding "fits" when it became 2 years old. So, what I did was take some Flitz, and with my Dremmel set on low and a polishing brush (cloth) I "polished" the inside of the feed lips and the back of the mag where the back part of the cartridge "rode" up the mag. You see, after a few years of use, a bit of oxidation of the metal had made it just rough enough to "drag" on the cartridges. After the polishing the mag worked fine.
So, you may want to polish the inside of your mag. Especially the feed lips.
FWIW
Dave