Centerfeed feeding help needed!

Got my first build "done", but a few things remain, namely some magazine work. This is off a model 12 stainless cf sa with blind magazine, and everything works smoothly BUT when I tried to load the magazine to cycle through rather than just feed single rounds manually the rounds would not feed. The bolt cathces the rim at first, then after the bullet tip hits the feed ramp or shortly after the bolt slips over the top of the cartridge and slides forward with no bullet. What did I do wrong or what must I change to make the magazine functional on this gun? Also let me know if you need more info (or even pics) so we can get this thing functional! Thanks,
Luke

That magbox was for a 22-250. Not sure what caliber you are using, but you may need to tweak the feed lips just a tad to allow the the case to come up a little. It fed my 22-250's just fine though.

If it's a .308 now I may have to widen the lips a bit you think?

How do you bend the spring steel that the box is made of?

I found the best way to bend the lips on a magazine is by using a crescent wrench. Just tighten down the wrench and bend. Pliers usually do not grab evenly and they are more prone to scratch the metal.