Mullerworks is a relatively new manufacturer, but Dan Muller is a long-timer in the industry. Dan has been deeply involved in several top barrel manufacturers - both cut and button - providing innovations and process improvements in an effort make the best barrels possible. Mullerworks is cut rifling barrels on CNC rifling machines he built himself, offering infinitely variable twist rates in both 4 groove and 5R. The arrangements we have with MullerWorks will likely produce special order barrels faster than other manufacturers. These barrels will NOT disappoint. The Mullerworks 22 rimfire barrels are among the best in the industry.