About
Dan Muller has been making barrels – both cut and button – for nearly 30 years. In the early 1990s Dan started out volunteering on his weekends with the barrel maker Mike Rock. Dan and Tim North worked together to bring Broughton Rifle Barrel production to Wisconsin in 2002. Dan joined Rock Creek Barrels in 2005 and has been involved in all aspects of the production process. Dan purchased his own barrel-making equipment in 2009; since then, Dan has built additional machines, plus has designed all the tooling for both cut and button barrels we currently make today. In late 2016, Dan split MullerWorks into two separate companies, MullerWorks, Inc. and MullerWorks Manufacturing, Inc. In 2025 Dan met Greg Brooks through a mutual friend Paul Tolvstad. Greg was a stock and gun builder who was a fulltime business professor at a small private college in northeastern Indiana. During the summer of 2025 while off work from the college Greg started volunteering with Dan at the shop in Wisconsin. After working together over the summer Greg decided to leave his job and start making barrels and building stocks and guns fulltime. In January 2026 MullerWorks was purchased by Greg Brooks (Rabbit Hole Precision). Dan and Greg now run MullerWorks collectively. Dan leading machine and tooling development as well as quality assurance and Greg helping to run production, administration and manage the back end of the organization. Together they formed a solid team, with Wayne Anderson, Brian Thompson and of course Paul Tolvstad.
Drilling
The blanks are drilled on a modified double spindle Pratt and Whitney gun drill, and each barrel blank is inspected for run-out and straightness. After drilling and inspection, the next step can either be reaming or contouring.
Reaming
Reaming is done on a CNC machine which Dan designed and built using bore reamers which have been
designed and manufactured to his specifications. Dan selects the reamer based on whether the finished product will be a single point cut or button barrel.
Contouring
Contouring is done on a HAAS S20L CNC lathe utilizing a pair of hydraulic steady rests for consistency in the tapers and size as well as to minimize the amount of induced stress during the contouring process. This allows for a precise and consistent barrel profile.
Initial hand-lapping
Blanks are inspected with a bore scope and precision measuring tools to check the quality and size of the ream plus ensuring a uniform bore from one end to the other. Then each blank is hand lapped to remove all tool marks and inspected again to prepare it for rifling.
Rifling
There are two types of rifling: single point cut and button:
· All single point cut rifling work is done on a CNC rifling machine which Dan designed and had built to his specifications. This unique machine allows Dan to select the twist rate and number of grooves the depth of cut per pass the number of cycles and cutting speed and cutting forces. The rifling machine components were selected for high degree of accuracy and smoothness during operation.
· For button rifling, Dan developed a special lubricant which significantly reduces the pull forces during the buttoning process, which ensures that a consistent pressure is maintained as the button travels through the entire length of the blank. The lubricated blank is rifled on a machine Dan designed and built. This machine has the capability to produce a broad range of twist rates. After inspection, the button rifled blanks are heat treated in a small furnace on site. Heat treating ensures that the stresses that are put into the steel blank during the rifling process are removed. Afterwards, heat treated blanks are inspected again for sizing and any imperfections
Final hand-lapping
The final part of the production story is that each barrel is hand lapped to remove tooling marks from rifling. Hand lapping ensures that the barrel has the proper taper as well as a uniform internal surface finish from the breach to the muzzle.
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