Home Forums Hunting & Shooting Ask The Gunwriters Hard powder/carbon removal

I posted this on the 'Teslong' thread but thought it might be interesting enough to follow on it's own. Or maybe not. Anyway.....

This is a barrel with some hard powder/carbon that's accumulated in the space between the end of the chamber neck portion and the end of the case mouth that needs to be removed.

The first pic is the area after being cleaned normally. The hard powder is the dark band on the lower right. The grey area ahead of it is the 45 degree bevel as the chamber neck transitions to the throat/free bore/leade area. You can see that that bevel has been well cleaned by the normal cleaning process. The angle makes that bevel appear quite a bit wider than it really is.



To get after the hard powder, I use a bronze brush that's one caliber larger that the bore size. This is a .30, so a .338 brush is used. The brush goes on a short pistol cleaning rod and the leading edge of the brush is loaded with JB Bore Paste. The brush is gently inserted until you feel it stop at the end of the neck. Mark the cleaning rod to keep it in this spot. Make 10-12 complete turns of the brush in a clockwise direction. Watch the mark you made and make sure you're not shoving the brush into the bore. Remove the brush using a clockwise rotation. Clean the chamber with a bore mop and push a wet patch down the barrel followed by a dry one. Check your progress via the Teslong. Depending on what you see, you can adjust how many rotations of the brush you give it. About 30 is where the JB breaks down and gets less effective. Clean the brush with some spray brake cleaner, etc. Repeat as needed until it's gone.

Second pic is done as described. After 12 turns, the hard powder is already about half gone.



How much a barrel is going to need depends on a lot of things. The amount of gap between the end of the case neck and the end of the chamber is the primary factor followed by neck clearance. Obviously a chamber with .008 neck clearance is going to load the area quite a bit more than a chamber with .003 neck clearance. Add in case volume and powder characteristics and it's easy how some combinations can get to be a mess in this area. The combination of big case volume, large neck clearance, necks way to short for the chamber and bunch of slower burning power and lower charge weights is about the worst.

Good shootin' -Al