Here is what Barnes has to say about CR-10 Bore Cleaner on
their website:
"Barnes' specially formulated CR-10 bore cleaning solvent
effectively removes copper and powder fouling. This
aggressive bore cleaner quickly loosens and lifts heavy
copper deposits left by jacketed bullets as they pass through
the bore. Leaves rifling clean for better accuracy, longer
barrel life. CR-10 bore cleaner is non-corrosive an won't
harm barrels."
I tend to agree. I have been using CR-10 in cleaning of
barrels in several rifles and handguns since they provided me
a sample to test. It has proven to be the most aggressive
copper removing liquid I've used to date. It has also proven
effective in removing powder residue but is a bit expensive
for that chore. I can buy nitro powder solvents much cheaper
and use them for the initial cleaning after firing for 3-4
patches and then switch to the CR-10. It aggressively attacks
the copper residue in the barrel and removes it better than
any product I've yet tried in liquid form.
I recommend you not leave it working in your barrel for more
than 15 minutes at a time without removing it. The other day
I was cleaning two rifles at a time, a Rem 700 LSS Mtn. Rifle
and a Ruger #1B and left it in the Ruger barrel for probably
45 minutes or so while changing targets and doing a few other
chores. It was left in the R700 LSS barrel for the same
length of time. I noticed no ill effects on the Remington but
noticed a light coat of rust forming on the blued steel Ruger
barrel. It came off quite easily with a single wet patch and
I don't feel any harm was done but I can see how leaving one
of these aggressive ammonia copper solvents in a barrel too
long can cause some etching/rusting of the barrel. Of course
following the instructions would have prevented this but I
was busy with other chores and let it set longer than
recommended.
After use I use a single dry patch followed by a couple of
patches wet in a nitro powder solvent to follow up the use of
this or any other ammonia based copper solvent. I then use
another dry patch and if putting the gun away as opposed to
shooting it I then follow that up with a patch wet with
oil. I suggest you do the same.
Barnes CR-10 definitely gets a Graybeard Seal of Approval
for
cleaning stubborn copper deposits from your rifle or handgun
barrels.
You can visit the Barnes Bullets Website by clicking the name.
Barnes Bullets
P.O. Box 215
American Fork, Utah 84003
1-888-BARNES-X
Fax: 1-801-756-2465