Minor barrel pitting - fix?

[kingston73]

It's not a S&W, but I just bought a 9mm with a 4 inch barrel that hasn't been shot much, but was apparently not cared for perfectly and has light pitting/rust inside the barrel. I haven't been able to shoot it yet so I don't know how or if it will affect accuracy. I just wanted to find out if there is anything that can be done to fix it, or at least minimize it? I've run a cleaning rod through it with Hoppes #9 and also a brass bristle brush, and then ran a few patches soaked with CLP through it and have let it sit with the CLP in it. I'll run some dry patches through before I shoot, but what else should I do?

 

[john traveler]

In 9mm, light bore rust or pitting does not affect accuracy. Just clean and oil it light you have done. Light pitting is more of a nuisance than anything else, because it makes bore cleaning more work. Repeated cleaning is needed to completely remove the bore rust. If left alone, it attracts moisture and the bore will continue to rust.

Heavy rust or pitting is ruinous to accuracy because the loss of bore metal actually enlarges the bore and groove diameters, reducing the ability of the rifling to engage and spin the bullet.

 

[n4zov]

John pretty much nailed it. You might use OOOO steel wool and oil to scrub the bore. Be careful to flush every vestige of the steel wool since it is very prone to rust and any little particles will worsen the problem.

 

[OKFC05]

Repeated cleaning is needed to completely remove the bore rust. If left alone, it attracts moisture and the bore will continue to rust.

It is extremely important to get ALL the rust out of the pits, which may take a lead/copper solvent to accomplish.
The rust acts as what the chemists call a catalyst to more rusting, and can cause rusting to actually continue under a layer of oil.

 

[kingston73]

Thanks for all the replies. Is there a better solvent to use for the rust than #9? Any suggestions? And this might be a dumb question, but how do I know all the rust has been removed?

 

[OKFC05]

Is there a better solvent to use for the rust than #9?

I prefer Hoppes Copper Solvent or Shooter's Choice.

The only way to be absolutely sure all the rust is out is to use the Outer's Foul Out electric system, but after cleaning a rust barrel every couple of days for a couple weeks, it should be pretty much out. Let the solvent soak per manufacturers instructions. You are trying to get the last molecule of rust out of the bottom of microscopic pits; the big stuff you can see is easy to remove.

 

[kenster]

Try Gunzilla. It's a CLP cleaner that claims to remove rust and protect against future rust. Top Duck Products, LLC., Creators of Superzilla and Gunzilla