doublegunshop.com - home Forums General Discussion DIY Gunsmithing @ doublegunshop.com dent repair in shotgun barrel

have purchased an extra set of barrels for a stevens 311 in 410. one of the barrels had a dent about 8" from the muzzle end and needs to be raised ect. have had several dent removed from 12 ga barrels and have been satisfied with the results. am aware of the metal slug and the screw expander device used inside the barrels to raise the dent and recontour ect. the 410 barrels appear to have thicker metal than say a 12 ga barrel and want to know how well dent removal works when it is used on 410 barrels. anyone out there have any experiences they can share on 410 barrel dent repair?

I do not have any dent removal experience with .410 bore barrels, but have removed dents in 20 ga. barrels. I can't say that was any more difficult than raising a similar dent in a 12 gauge barrel. Considering that your dent is about 8" from the muzzle, I don't imagine the wall thickness there would be so thick as to make dent removal all that difficult.

Some years back, I built a hydraulic dent raising tool and used 1/2" EMT conduit to test it out. The wall thickness of the galvanized steel EMT was .042". I could make some pretty healthy dents in it, and then easily raise them with the hydraulic pressure of the anvil alone. I know jacking a dent up with hydraulic pressure is NOT the proper way to use a hydraulic dent raising tool, but I wanted to see what it was capable of. I was able to easily produce over 3000 psi of pressure. It was evident that a hydraulic dent raising tool used this way could easily turn a dent into a bulge, even with steel tubing thicker than the average forward portion of a shotgun barrel.

So in short, I wouldn't over-think it or worry that it can't be done. It doesn't take a whole lot of force to dent a shotgun barrel, and it doesn't take a whole lot of force to remove that dent either.

thank you for the reply. have did little work on 12 ga dents. the barrel thickness looked to be "thicker" on the 410 barrels than a 12 ga. with no experience on a 410 was looking for suggestions. my method will be using sized slugs inside the barrel, brass hammer and aluminum tape for a pad.

Aluminum tape works well for that, in my experience. I've never done it on a .410 either, but I think you can do it even with the thicker barrel walls. May require more time and patience, and hammer "pecks".

I am fortunate to have a small metal lathe to make plugs for removing dents and other things. What I do is measure the internal diameter of the barrel right before the dent, (since there are no gages to measure a.410 you could use a plug diameter of .410 and see if that fits and go from there. There are a few companies that make hardened plug gages but they do no have a beveled edge and I would not try them in the bores of any gun. I then make a tapered plug so that the front taper passes under the dent and the main body of the plug is .001-002 smaller that the diameter of the barrel. On the back end of the plug I drill and tap for 1/4x20 so that I can thread a rod into it. I then heat the barrel with a propane torch till warm and then tap the plug till it goes through the dent area.
You can also leave plug where it gets tight in the barrel and tap the outside with a small fender hammer, the one with the large flathead. Like stated by Keith I have never done a .410 but shouldn't be any different than any other guage.

Is the heat required? To me it seems you wouldn't get it hot enough to affect the steel ,,and if you did you would have trouble with the solder melting I have never used heat

No, not required. I've removed several dents with plugs, and also with an expanding mandrel type device, but always using a very small hammer. I've never used heat.

On another forum years ago the conversation was on dent removal and I had replied on a question about what I do. A gentleman replied that he was a gunsmith for 40 years and he suggested to apply a little heat in the area of the dent, just enough to get it warm. His theory was that in doing so you were moving some of the molecules of the steel around and would help in raising the dent. Ever since then I have used heat on any gun I get that has a dent or so. Never enough heat to melt solder which is about 450 deg. just warm to the touch.

Interesting, David. Can you offer a comparison on how it works with a little heat as compared with how you previously did it with no heat?

Well Mr Williamson I'll give it a try I have hydrolic and I make metal slugs but I have never tried heat