There's a DIY zero-stop that is super easy. It consists of hose gaskets and thin washers placed in the top inside of the turret cap.

With my 45 moa bases,I just put one hose gasket in there, and my turret bottoms out about 3 mils below zero. I could shim another thin washer in there to get closer, but as it is I can spin it to the bottom and return up 3 mils to the first zero.