Need Help removing the rear sight base on my mosin 91/30
so i'm trying to remove my mosin's rear sight base so that i can mount a dovetail to weaver rail mount thing-a-majig. anyways i removed the two base pins the set screw and the leaf spring and sight piece but the dang base wont budge. any suggestions? i heard heating it up might help if its soldered on but i'm not sure if it is or not? thanks
Yep, need some heat. You only need to heat it enough to melt the solder. Do you have the top handguard off? If not, you need that off so you'll have enough room to tap the sight off. Best thing is to either have a helper or put the rifle in a vise or clamp somehow, so it's held nice and solid. That'll help a lot. Heat the sight base up until the solder flows, then tap it forward gently. I'd use something softer than the steel base, like a brass hammer, a chunk of brass or copper, or a brass punch and a small hammer.
I took mine off this way, and I wasn't really even trying hard. I'd read about the procedure and thought I'd mess around with it. Next thing I knew, it was off and I was cleaning the dovetail up. I used an acetylene torch with the smallest tip I had, but a decent propane torch would probably work, MAPP gas may be better. Just don't heat it too hot! Keep the flame moving and heat it evenly on both sides. Ain't rocket science.
I only have experience with a few. Propane would NOT budge any of mine. Map is the min and acetylene is the best and please use your head. The barrels aren't tempered so don't worry about softening them and NEVER quench them or they will get brittle. From what some have said there are three conditions 1. No solder and it drives off easily. There are few of these and it is a mfr. flaw. 2. Plain lead solder is used and a propane would do the job eventually but that barrel is a large heat sync so you will be heating a while. 3. What some call solder is actually "German" or Silver solder and that needs as much heat as brazing...almost. But it sure as heck needs way more heat than lead solder.
After you get it off reheat the barrel and rub the last solder with steel wool that has been whetted with "acid" flux used for plumbing solder. work. That new lead free plumbing solder won't mix with the old lead stuff....oil and water so to speak. Don't ask me how I know that or how many trips I made to the store before they figured out how old I really was.