Anyone else had to do this? After probably a year and a half with a fiasco getting my barrel, I was finally able to get my model 10 built. The specs are as follows:
Model 10 center feed (4.4 spacing) left hand action.
Choate ultimate varmit stock.
CDI inletted the stock, and also bought their DBM.
Magpul AICS mags.
I chose the magpul mags because of their cost. I bought two magpul mags for way less than what I could buy one AI mag.

First test fit, the mag would not fully seat, it hits a contoured area of the underside of the receiver.




This was preventing the mag from seating deep enough to not only allow the bolt to catch a round, but also prevent it from locking in place with the mag catch.
I started out with a exacto knife then moved to some rough grit sand paper and a sanding block.
After a little re contouring, I was able to get them to seat properly to where they would feed rounds normally.
It is a little hard to tell, but the modified is on the left, unmodified on the right. You can just barely see the the scribe mark I made with the exacto knife on the right mag to where I could mod it to match the first one.



Now that they would fully seat and feed, they still did not lock in place. The mag catch was too long. Also the spring on the mag catch was excessively stiff. I do not have any pictures, but I ended up driving out the roll pin and shorting the mag catch by probably 1/16 in or maybe a hair more. I also cut a couple coils off the mag catch spring. It is now at a normal usable tension.

I have the exact same stock, and CDI bottom metal on my long action model 111, also using a magpul AICS mag in it as well. I did not have to do any of this to it, so not sure why this one is so different.

But anyways, finally done:






Model 10 left hand, timed and trued, choate ultimate varmit stock, CDI bottom metal, x-caliber 26 inch, 1in bull, 308 win, 1-10 5R, precision armament M11 muzzle brake, sightron 10-15x60 scope.
Action is blued, barrel and precision ground recoil lug are stainless. So I kinda have a two tone look going on. Part of me kinda likes it, part of me may paint it black. Have not decided.