I've got a JC Higgins 50 project rifle that was a bit of a beater when I got but it has nice walnut, a smooth action and it is very accurate. In working through this project I've decided that I want the sights removed before I make my first ever try at rust bluing with this rifle.
I've tried heating with both butane and propane without success not knowing what kind of solder was used. The nearest gunsmith is 2 hours away. When I spoke to him on the phone he said it would require heating to red hot. His price is reasonable but I'm worried about harming an excellent barrel. I see a mix of online references saying red hot is reasonable and others saying it is a terrible idea. Would you let red hot happen to your barrel?
Not me but, it was once done to establish it is the first place. If it were me, I would cut it off, the sight I mean
The gunsmith did mention that it had to be that hot during installation which made sense to me. I just see so much conflict information that the advice of others is appreciated.
What would be your motivation for cutting it off rather than heating it?
You only have to get the sight red hot to get it off. Acetylene is the way to go to get it up to temp and off quickly.
Heating the sight to red heat will likely be enough to melt the braze (or solder) metal, but you need to protect the bore from scaling. If you don't have a commercial anti-scale compound, you can make a tight fitting wood dowel about 6" long to drive into the bore under the sights. This will char and take up all the oxygen in the little bit of air space between the dowel and the bore thus preventing scale formation. The localized heating will not harm the barrel metallurgically.
RAN
Model 50s have a chrome bore, will that matter?
I would just leave it on and go ahead and rust blue it. Why not do otherwise?
I like having a front sight.
It helps keep the gun from sliding if you lean it on a smooth bark tree.
The only reason to take it off is simply that think I'd like the looks of it. If it turns out to be a hassle I will just leave the sights on.
As it turns out I was talking to a neighbor who lives eight doors down the street and he has a business from home as a jeweler. Because of this he has oxy-acetylene torches that should be very suitable for this job and he is certainly used to fine work. He's also a gun owner so I'm sure he'd take it seriously. We are planning to give it a try later this week.
Pay heed to the warning about scale forming in the bore under that high heat.
Why I'm fond of Brownell's high strength "soft" solders, plus a MAPP torch is enough. Theoretically you can hard solder without scale but as a practical matter it's hard to control the heat that carefully. Though removing a piece would be less troublesome as it falls off when you reach the minimum temperature. I don't know enough about anti-scale compounds to have an opinion.
I silver soldered lots of front sight ramps and recoil lugs when I worked in the Browning Arms gunsmithing shop, I can assure you that it is not necessary to heat the sight till it is red hot. The solder will be soft enough to remove well before reaching red heat, you will need to protect the bore with an anti-scale compound. An oxy-acetylene torch is the tool for the job, pay attention to the sight while heating and you'll be able to see when the solder melts enough for the sight to be removed. I have also rust blued many rifles and never felt the need to remove the sights.
Induce harmonics/vibration.
The sight will JUMP off the Bbl.
No heat required.
Just keep adding more/faster powder. I guarantee sooner or later something will jump off.