Plugging a barrel for rust bluing?

[webradbury]

I have rust blued plenty of parts but now have a barreled receiver that needs rusting/boiling. What is the best way to protect the bore/chamber? Rubber plugs, wood dowels (seems like a recipe for disaster) or coat the barrel with (?). I've read that shellac has been used to protect the bore and then removed later. Thanks in advance. Will

[colchester]

I have used silicone rubber plugs for parkerizing with great results. I use a tight fitting tapered plug pushed into the bore flush. I use a small hook shaped tool to remove them. Mc master carr sell em

[waksupi]

I found it unnecessary to do anything with the bore. I'm in a generally dry climate, and have had no problems with rust in the bore or inside the actions.

[Greg S]

If your going to tank dip it I would sat blue goo gasket material. Pushing corks and plugs in is fine for room temp stuff but might get some seepage. Once you start putting the part into hot solutions, pressure builds and can pop the corks so to speak.

[gnoahhh]

I've had plugs pop out, probably from expanding air in the barrel while in the boiling tank. I quit using plugs and found no ill effects. I run a dry patch through the bore after boiling and before carding, and the hot steel dries whatever water is left in there immediately. Fuggetabout de plugs!

[webradbury]

Excellent! Sounds good to me.

[RustyReel]

I don't plug the barrel either. I do one additional step (which is probably unnecessary). I de-grease a new bore brush and my cleaning rod. I give the bore a few passes with this after each heating just to card off any solution that may have wandered into the bore somehow. As noted, probably unnecessary but makes me feel better.

[jeepvet]

Let me be sure that I am understanding what y'all are saying. When you rust blue a barrel you do not plug the end of the barrel or chamber end? Just put it in the solution and when done and cool you run a few patches through the barrel and shoot. Right?

If so, will this method also work for Parkerizing a barrel and action?

[blikseme300]

Rust bluing and Parkerizing are way different. Rust bluing solution is wiped onto the areas you want to blue and nothing is dunked into solution. With rust blueing I don't bother plugging the barrel when doing the boiling in distilled water as the short time the naked steel is in contact with the water does no harm. After the boiling I do blow out the water from the bore with compressed air and then dry everything using a heat gun before carding.

[LAGS]

I do not plug the barrel either.
But I make sure not to get any of the rust blue liquid inside the barrel when like doing the crown.
And I always run a CLEAN bore brush and then a couple of clean dry patches thru the bore as soon as it comes out of the boiling tank.
I have never had any issues with rust in the barrel.

[Clark]

I built a VZ24 260 Rem with a Douglas factory long chambered factory blued barrel. The blueing was on the inside too. It would shoot a tiny group, and then be Copper fouled.
I have read threads on this topic in the past, and opinions seem to be split.

[2152hq]

Rust bluing (either express or slow rust blue), I never have plugged the bore to do the bluing process. The bluing solution is never applied to the bore. Only boiling water touches the bore and evaporates immediately as the bbl comes out of the tank. I do run a dry patch down the bore when slow rust bluing betw application cycles, but that's it.
Slow rust cycles run anywhere from a couple hours to 24hrs, with no rusting soln applied to the bore and just clean unprotected metal in there, I have still never had any rusting of the bore occur. That's in 45yrs of doing this.
I know some that still insist on plugging the bores and that is their way of doing their work. I won;t argue with that.

Hot salt bluing (used by the gun industry and since WW2 generally) immerses the part in a bluing soln, so the entire part including the bore will be blued if not plugged. If you do decide to plug the bores during this or the above process, the chance of the plug(s) blowing out are a possibility as the air pressure rises within the bore while the part is in the tank.
The above rust blue applications are in boiling water (212F). That can easily do it though and to have boiling water splattered on you while working is not a good thing..
This hot salt bluing soln is a heavy alkali soln that is boiling at right around 300F. Very dangerous to have an explosion of air pressure from the plugs blowing out while in that solution.
It does no harm to leave the bore open.

Use eye protection and protective clothing when doing either process no matter which way you choose.