Problems with new Kimber

I bought my first 1911 today, I went with Kimber as I feel it's the best value for the bucks. I decided on a Stainless & Aluminum ProCarry. About the same weight as a CDP but a few hundred cheaper. I went to the range and using a Chip McCormick aftermarket *rd mag and 185 Grain Winchester Winclean semi stovepiped every 3-4 rounds, I tried 230 Grain Winchester ammo and had the same problem. Hmmm extractor? Switched mags to the factory 7 rnd and only had it happen twice in the next hundred rounds. Still too often. Is this a break-in issue? When it shoots it's awesome but I'm going to keep carrying my Glock until this is resolved.
Recoil isn't much more than the 5 inch barrel and much heavier classic Kimbers I've shot, really like it.
I noticed the barrel was dirty when I brought it home also ran some patches through it & I would swear it had had a couple rounds through it without cleaning, are they factory test fired and not cleaned?
I broke it down when I got home and was kinda suprised at what I considered rough finish inside, I took a dremel to the rough feed ramp till it is nice, smooth and shiny.
The magazine release is a bear too sometimes it binds. Thoughts anyone????