cleaning paint residue

[Newboy]

I have a lot of 9mm boolets cast. sized to .358. I am unable to size any larger and still get them to feed in my Walther PPQ barrel.

Used a homemade expander, so slugs are still .358 if pulled from the cases.

Using real soft alloy, shoots well for IDPA. Probably 1100 fps.

No leading, and using bb's and shake coating. Using ALL POWDER PAINTS, which I am very pleased with. Very fine powder, good coating.

Using an oven from WalMart, and check the temp with a thermocouple to verify.

No leading at all, but after 100-200 shots, I am getting a paint residue on the trailing side of the rifling lands, from the throat out maybe an inch. The more I shoot, the more it builds up.

The coating is cooked according to the instructions. Good coating, as per the hammer test.

This paint coating is unaffected by any of my regular gun-cleaning solvents. I have tried the Lewis lead remover, bronze brush, Chore Boy pads, as well as the previously mentioned gun solvents. The only way I can get this out is by maybe 100 passes with a bore brush. This stuff is much harder to get out than normal leading.

Any ideas? Soak barrel in acetone?

[ioon44]

You might try Kroil, it seems to loosen up almost any thing.

[rsrocket1]

Sounds like you're gas cutting the paint and it's getting deposited before the bullet can seal the barrel (or the pressure drops enough to allow the polymer to seal the bore).

I've heard that an Acetone/ATF mixture is the best penetrant ever, but I don't know if it will physically get under the paint deposits.
Here's some powder coat dissolvers (http://solventkleene.com/pcstrip.htm). I don't know how nasty they are to your health or barrel so please read the warnings.

[Newboy]

I believe the gas cutting is correct.

Kroil has no effect.

I will check out the paint solvents. They can be bad, but I will not be handling it. I can just dunk the barrel in, if I find something.

thanks

[bangerjim]

Forget all your "common" gun solvent You are not dealing with grease or lead here!

Start with pure Acetone/brush/patches. Plug each end with some pathes or rags and let some Acetone sit in the barrel for a few hours. Brush well and the patches.

If that does not cut it, use MEK.

Both are easily avaialble in quart cans at any big box hardware store.

You are calling this "paint". It is not paint, I t is a baked on powder coating that much tougher than any paint, even epoxy. I shoot thousand of PC's boolits thru lots of guns and have never had your problem.


Mor than likely you are getting gas cutting as said. PC is NOT equivalent to FMJ's and you MUST use a copper gas check if pushing velocities above sub-sonic.

bangerjim

[VHoward]

Be nice if he had a chronograph to see what his velocities really are. 1100 fps isn't really supersonic, but it could be too fast for this particular gun. I load a 130 grain truncated cone in 9mm over 6 grains of AA#5 and don't have this problem either.

[popper]

Soak barrel in acetone (or MEK) & use harder alloy. Wrap choreboy strands around the bore brush. If you have 'color' PC in the grooves, not cooked properly. Burnt PC is dark grey no matter what 'color' you use.

[Newboy]

Thanks for the help.

I just finished my "science experiment".

I suspended the barrel in a graduated cylinder of acetone for a few hours. It softened the coating, allowing me to wipe it out with one pass of a brass brush.

Interestingly, if you take it of the acetone and let it sit for a couple of hours, it gets hard again.

[bangerjim]

One of the early PC'ing methods was to dissolve powder in Acetone and slop it on. Worked for some.......not me. VERY messy and lumpt and required 2-3 coats.

PC will dissolve in acetone and laq thinner (made from acetone) and MEK. When evaporated the PC will generally harden again.....with undocumented and uncontrolled results.


Glad our suggestions on here worked for you!

banger

[bstone5]

Put a Cola Can gas check on the base of the bullet for a tight seal.
The gas check will remove gas cutting, if the color in the barrel is the same as one the bullet it may not be gas cotting.
Cook a little longer.

[Love Life]

Harder alloy and check your throat. Gas check I not a MUST to go supersonic. However, the correct alloy and hardness for your application is.

[runfiverun]

basic cast boolit fitment rules still apply..
P/C isn't a cure-all to every ailment.

[Love Life]

basic cast boolit fitment rules still apply..
P/C isn't a cure-all to every ailment.

This one post (the one quoted) should be made into a humongous banner at pasted up in the stickies.

[Case Stuffer]

basic cast boolit fitment rules still apply.

Perhaps alloy hardness should also be added to the proposed humongous banner.
I keep reading a lot of post which suggest that hardness no longer matters much at all. IMO just because softer can be power coated and shot without leading does not mean they will be accurate. Surface hardness of the power coating will not prevent stripping or will it?

[popper]

Gas check I not a MUST to go supersonic green guy with long ears?

[Love Life]

Gas check I not a MUST to go supersonic green guy with long ears?

Are you calling me a troll? Please speak plainly.

I say again, a gas check is not a MUST to go supersonic.

[runfiverun]

I think he was trying for Yoda.

[Beagle333]

Gas check I not a MUST to go supersonic

haha... that hung me up too, the first time I read it. I thought he was going for Yoda as well. :grin:




well yeah, it makes sense NOW..... 8-)

[Love Life]

I'll take yoda. He was legit!!

Apologies for my cantankerousness.

[popper]

Sorry, senior moment, couldn't remember his name. It is fun when the wife is doing crossword and I answer a few minutes after she asks, then says 'it doesn't fit'.

[62chevy]

Perhaps alloy hardness should also be added to the proposed humongous banner.
I keep reading a lot of post which suggest that hardness no longer matters much at all. IMO just because softer can be power coated and shot without leading does not mean they will be accurate. Surface hardness of the power coating will not prevent stripping or will it?

I like to say fit is king and harness matters when it matters. Or worry about fit first then hardness.