What's the best way to remove rust from a bore?


July 10, 2003, 03:22 PM
I recently got a couple Star 9mm Largo pistols from SARCO. All in all nice pistols but they both have rust in the bores. It's not really deep, but it's been there long enough to have caused some light pitting.

I have at my disposal: Birchwood Casey Blue & Rust Remover, Breakfree CLP, WD-40, Sweets 7.62, J-B Bore Cleaner and J-B Bore Bright.

What's the best thing I can use that will dissolve the rust? It's not as simple as "outside" rust which can be removed with a little oil and steel wool.

:confused: LL :confused:

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Bottom Gun
July 10, 2003, 04:47 PM
I had good results once using Breakfree and a brass pot scrubber on the end of a cleaning rod.

July 10, 2003, 06:17 PM
Clean the barrel so the rust does not intrude into the bore and cause high pressure. Then take your cleaning stuff to the range. Shoot the gun till the barrel is HOT. Clean and scrub quickly while hot (the brass pot scrubber is a good idea). That will help a LOT.

July 10, 2003, 09:14 PM
You are stuck with the pitting but ...... give a good scrub with a mild solution of wash up liquid (Dawn) as a ''wetting agent'' ...... used with a stiff and suitable cal bronze brush. After several applications of this with rinses of water ....... you should find discoloration decreases quite a lot. Next ...... use same brush or even a mop ...... and swab thru the bore several times with a rust converter .... based invariably on phosphoric acid (even Pepsi can work!!). This converts the remaining active rust areas to a phosphate which will appear darker if looked at.

Leave for a short while and then rinse once more with clean water until no color shows. Now dry off moisture .... hot air gun ... low oven .... whatever suits.

Then ........... SHOOT THE HELL OUTA THE THING!!! .. after that clean in normal manner and leave with light film of CLP in the bore for storage .... it should finish up having removed all the rust that could cause any over pressure probs and also probably leave the pits fairly rust protected .. they may well fill with copper or lead .... depending on bullets used.

This is only a suggestion ... something to consider.

July 11, 2003, 05:10 PM
Thanks for the advice.

I'm pretty sure the Blue & Rust Remover is phosphoric acid based, so I gave it a shot. Basically took a worn out 9mm brush, wrapped a patch around it and soaked the bore a minute with the B&RR, scrubbed and rinsed. I didn't leave it long as I don't trust leaving this stuff on any metal for more than a minute. After two times, the bore flushed out pretty clean. I then gave it a normal CLP/bronze brush scrubbing followed by a jag. Rifling looks pretty good. Worn, but there. The bore is a little rough, but doesn't seem deeply pitted and it doesn't snag a patch run through it.

I think it's now clean enough to take to the range and give it the "hot clean" after a magazine is rapid fired through it.

Thanks again,
:) LL :)

July 15, 2003, 03:00 PM
Find a really rusty nail or screw.
Put is in a solution of salt and vinegar overnight.
Take it out, wash it off, and notice the rust is gone.
There is some metal gone too, as the screw is sharp as a knife.
This technique can be used to sharpen files.

I have also heard about Outers Foul Out taking out copper for a while, and then getting rust out of the pits.

When I get the red color in the bore from disasociated moly that turns to acid, I use FLITZ, which works like JB bore paste, only faster.

July 15, 2003, 10:08 PM
Clark .. I can feel ''experiment mode'' comin on!! How much salt? saturated solution or weaker? Is that malt vinegar or cider (ie, Acetic acid or malic).?

July 16, 2003, 12:10 PM
I had an Enfield with a rusty bore, very rough, tried brushes, even steel ones and also some Rem Clean, no luck. I then took the Birchwood Casey Rust and Blue Remover, I plugged the bore and poured it full. I let it sit for two minutes and then drained it off.

Cleaned with a brush and solvent. Came out almost shiny! No pits at all and the gun will now hold a 4" group at 100yds, not great but for a salvage piece I was pretty impressed. The only thing left to do was rebarrel and that's not feasible for a $100 rifle!

July 16, 2003, 01:46 PM
I have had good results with Blue Wonder Gun Cleaner on very old barrels.

July 16, 2003, 09:38 PM
Any acid will remove rust, whether phosphoric, as in Naval Jelly or Coca Cola (it works, an old body man's trick,) acetic (vinegar,) ascorbic (lemon juice,) or hydrochloric (muriatic.) Again the downside is hydrogen embrittlement...degas as required after treatment.



July 17, 2003, 04:10 PM
Thanks for the additional info.

As I mentioned previously, I did use the Blue & Rust Remover and then took it to the range to blast it clean :)

The bore is now quite shiny with strong rifling. Unfortunately it is indeed pitted, but accuracy didn't seem to suffer too much from it. Since it's a milsurp more for collecting, it's no big deal and I just need to keep an eye on it to make it stays rust free.

Thanks again,

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