I suspected that the QC was quite good but I also feel that the design- simple and very stiff contribute to the great accuracy. If you can get around all that damn plastic, they are really quite good rifles.
When machining stuff whether robotic or by hand, you have to deal with tool wear. If you don't have processes in place that check the tool wear, you will get some dimensional changes. I suspect that some will get chambers that were near the end of a reamer's life and will be a little smaller than a fresh reamer will cut. A slightly worn insert will also cut a different dimension than a fresh one- even if we are only talking 10th of thousands. They must have a good program in place that keeps these variables from adding up.
Did I mention that I hate all that plastic?
