I ran into the same thing on the mid section, not the front receiver section you have pictured. My barrel is also 0.960" diameter per spec. I modified the step file with a larger diameter for the mid section so that it tightly slid over my barrel (it was originally 0.954".)
I ran into the same thing on the mid section, not the front receiver section you have pictured. My barrel is also 0.960" diameter per spec. I modified the step file with a larger diameter for the mid section so that it tightly slid over my barrel (it was originally 0.954".)