"He wants it to fit in such a manner that an audible snap is apparent in the final turn as the shoulder engages the action face, and the barrel should be somewhat difficult to break loose even though it is only hand tight."
That is a quote from another board about a Calfee's guns barrel threading and lock up.
That goal was achieved here. Dykem machining dye was also used to show a nice uniform seat 360 degrees around the shoulder and face.
Here is the Suhl receiver with a thread machined out.
Here are the finished barrel threads.
A proper reamer is important. What is proper is a reamer for the type of ammunition to be used. The reamer chosen is from Dave Kiff at Pacific Tool and Gauge. This is a universal reamer with a slight taper. The reamer favors Lapua ammo.The cases of Lapua, Midas, Master, Sk Plus, and Wolf all have a slight taper.
With the reamer chucked up, the depth collars are visible. The collars allows the penetration of the reamer to be adjusted. A feeler gauge can be inserted between the adjustable collars for very accurate adjustments.
A borescope is essential for looking for defects in the chamber and other inspection tasks.
A headspace gauge is used for verifying headspace.
After the headspace is verified. A live round is chambered.
The engraving looks good just past the second driving band.
As the Calfee article over in Benchrest Central states "The rifling marks the bullet just past the second driving band and each mark is of consistent length. Bill explains that this indicates the chamber is not canted but has run straight and true through the process. He again checks the headspace and it seems to be right where he wants it."
Calfee cut his chamber by hand. This chamber was cut using the best tooling, machining technique, and measuring tools available.
However there is one last process to be done by hand. A slight chamfer will be lapped unto the back of chamber. The geometry of the lip will be unchanged. Dry firing a rifle like this is not a good idea.
