Handlapped Barrels and the use of Final Finish
by David Tubbs
Bore polishing process you do yourself!
A handlapped barrel should be extremely well finished on inside (close to 400 + abrasive in smoothness), and have good interior uniformity (dimensions). When chambering this barrel annular tool marks are created in the chamber and throat areas. Polishing most of the tool marks out of the chamber is relatively easy; removing the tool marks from the throat is not. This is where Final Finish performs extremely well.
In the Final Finish kit there are 75 precoated bullets. When lapping the throat of a handlapped barrel, it is recommended that only the #3 through #5 polishing compounds be used. There are a total of 55 bullets in the #3, #4 and #5 sections. Use 5 bullets of #3, followed by 10 bullets of #4 and 10 bullets of #5. This is a total of 25 bullets. This will polish the throat of you new handlapped barrel as well as break the barrel in for extended shooting. Now you will be on course for the balance of the bullets in the Final Finish kit which are to be used when the barrel’s throat becomes rough (1/2 to 2/3 worn). The remaining bullets of compound #’s 3,4 and 5 can then be used to rejuvenate the throat area of the handlapped barrel. The compounds # 1 and #2 will not be used in the handlapped barrel.
Some barrel maker’s handlap some of their barrels while not lapping others. Using the bore scope some barrels which have been handlapped would still have benefited from the use of all the compounds (#’s 1thru5) in the Final Finish kit to attain maximum smoothness and uniformity.