Catpop,
I used this kit
to fire lap two stainless Ruger Vaqueros in .45 Colt. They had frame chokes that
took the groove diameter down to .4507/.4508" while the muzzle groove diameters
were.4511/.4512". They had noticeable leading just ahead of where the barrel was screwed into the frame.
I used soft cast unlubed bullets that I purchased from a now defunct bullet
casting company sized at .452". I prepared 100 lapping bullets using the
220 grit compound in the NECO kit. It took time to learn how much pressure
was required to embed the grit into the bullets uniformly. Once I learned
the bullet prep was a snap. But the entire bullet prep process is messy as
the compound is both greasy and gritty. And you need to thoroughly clean
your loading dies after making the lapping rounds.
I loaded them into some cases that I was ready to scrap. Once used for fire
lapping you don't want to use those cases for any regular load as some of
the lapping compound may be left behind embedded in them. I used 3.5 grains
of Red Dot. You want enough powder to push the bullet through the barrel
without fear of it getting stuck.
When I shot the lapping rounds I did five or ten at a time and then cleaned the
cylinders and barrel with Gun Scrubber, a bore brush and patches. I then
swagged the barrel and measured them with a micrometer. It took about three
hours to lap out the choked portion with all of the cleaning and remeasuring.
The end result was two guns that went from shooting 3 1/2" at 25 yards to
2 1/2". The barrels are now very smooth and when shot with lead have only
flecks of lead left in them that are pushed out with a dry patch or two.
)
