In this post we are going to take a look at how to repair the muzzle of a Mosin Nagat rifle that has been damaged.
This is how the rifle showed up at the shop. Apparently, at some point in its past, it had a steel plug welded in the muzzle. To remove the plug it appeared that the muzzle had been cut with a hacksaw and drilled. This process left a mess and the end of the rifling was damaged. Often, gunsmiths will counterbore the muzzle to create a false crown in the barrel away from the muzzle to fix this. In the case of this rifle, I felt re-cutting and crowning the barrel would be the best course of action.
Before we get to work, let’s take a look at the following disclaimer…
The contents of Rifleshooter.com are produced for informational purposes only and should be performed by competent gunsmiths only. Rifleshooter.com and its authors, do not assume any responsibility, directly or indirectly for the safety of the readers attempting to follow any instructions or perform any of the tasks shown, or the use or misuse of any information contained herein, on this website.
Any modifications made to a firearm should be made by a licensed gunsmith. Failure to do so may void warranties and result in an unsafe firearm and may cause injury or death.
Modifications to a firearm may result in personal injury or death, cause the firearm to not function properly, or malfunction, and cause the firearm to become unsafe.
For this project, I ordered the following items from Brownells:
I began by cutting off the most damaged part of the muzzle on the band saw. My saw is an old Powermatic 143 metal and wood cutting machine. When I started gunsmithing I rarely used the band saw, now it has grown to be my favorite power tool! There is something satisfying about rough shaping a part with one.
I secure the barrel vertically in a Multi-Vise with padded jaws. I then insert one of the arbors that comes with the Manson crown refacing kit. The Manson kit uses a series of carbide cutters that are turned with a hand crank.
The kit comes with a tool that cuts the muzzle at 90 degrees to the axis of the bore, as well as one that produces an 11 degree recess. I always start with the 90 degree cutter and follow with the 11 degree tool.
The finished crown looks great! I cut off enough of the damaged rifling that this rifle should shoot much better.