Solder For Shotgun Barrel ?

[Johnch]

I sort of was gifted a Winchester Model 12 12 gau shotgun the other day
Yea it was free

BUT someone in the past cut it down to 24" and had front and rear sights soldered on :(
To make a adjustable sight slug gun for deer hunting

OK not my choice , but someone else did that damage

But the front sight base is almost knocked off
Just barely held on , you can slightly move it with finger pressure

So I am thinking of re soldering it back tight
But not sure what solder to use or what solder was used on it before

What solder can I use that will not need enough heat to ruin the blue finish ?

Or would it be better to finish removing the front sight base
Then drilling a hole in it for a screw
And last drill & tap a hole for the screw in the barrel ?

I know I will have to clean up the part of the screw sticking into the barrel

But if I do anything
I want it to last and not destroy the barrel

Thanks
John

[Der Gebirgsjager]

Most soft solders will do the job. You should remove the sight, clean it's bottom and the area where it sits on the barrel of all bluing, rust, scale, etc. so both areas are nice and shiny. Clean the surfaces with acetone. If you don't know how to tin a surface with solder, Larry Pottefield has a good video on Midway USA's website. Tin the bottom of the sight, put a little flux on the barrel, clamp the sight in place and heat until you see the solder liquefy at the edges of the joint.

You can drill and tap it for a screw, and that's how beads are usually installed. A photo would be helpful here to determine what size screw should be used. Perhaps a dab of J-B Weld under the sight before the screw is put in, if the sight is long enough (has a short ramp) and could swivel if the screw loosened. When I install a bead I usually chop off the part of the bead's thread that is inside the barrel using a sharp edged large pin punch. One smack will shear it off flush with the barrel's inner surface. But a screw, being thicker, might require a little judicious filing or grinding.

[Bulldogger]

Fancy shotgun companies used pure tin for soldering, I read, but I have just used normal plumbing/electronics solder and made sure all was tinned and clean, as Der G says.
Bulldogger

[Geezer in NH]

I use Brownells 44/40 solder works. Works as an industry standard. I have used it for 35 years+

Note for sights not ribs that is different story.

[Johnch]

Thanks for the help

After the advice I removed the front sight base
Only held on by a 1/8" x 1/4" spot of solder

I cleaned everything 2 times and pre heated the barrel and base with a electric heat gun
I then used some 50/50 solder I had handy
I can now see a line of solder all the way around

Cleaned again and oiled everything to make sure of no rust

Pictures are a problem
As my camera has been not working for several years and my cell phone
Well I never can get it to show small things properly

Thanks again
John