Mainspring edge hitting barrel

[Larry (Omaha)]

I would not use a bench grinder on a tempered spring.

I’ve made plenty of springs, fitted them to locks. I’d use a smooth file and then polish it back with an emery pad or paper. You’ll find that you likely don’t have much to remove.

I only use bench grinders for removing casting gates on annealed steel parts or brass.

My bench grinder is low speed and I keep my fingers right on the work. Your pinkies will holler way before you kill the temper on a mainspring. This is my personal belief and been doing it for years. Now, a knife or sharp object is another critter cuz you have thin material which can heat in an instant. Again this is what I go by. File works too, no doubt about that.
Thanks for your reply and concern.
Larry

 

[Mr. Flintlock]

Hello,
I recently acquired my first flintlock rifle, and noticed there was a gap between the pan and barrel, maybe a 16th to a 32nd wide. I thought the lock just wasn’t inlet deep enough, but turns out it was the mainspring coming into contact with one of the bottom faces of the barrel! Photos attached. What would be a better method of solving this, filing down that edge of the mainspring, or filing down this particular section of barrel? I imagine it doesn’t matter too much, but thought I’d ask the experts! Thanks!

The mainspring is a lot cheaper uto replace than the barrel.

 

[Mr. Flintlock]

Hello,
I recently acquired my first flintlock rifle, and noticed there was a gap between the pan and barrel, maybe a 16th to a 32nd wide. I thought the lock just wasn’t inlet deep enough, but turns out it was the mainspring coming into contact with one of the bottom faces of the barrel! Photos attached. What would be a better method of solving this, filing down that edge of the mainspring, or filing down this particular section of barrel? I imagine it doesn’t matter too much, but thought I’d ask the experts! Thanks!

What is that hole in the barrel?

 

[Eric Krewson]

I have notched a barrel for a little more front lock bolt clearance and notched another one for mainspring contact, either way the metal removed wasn't as deep as a dovetail for an underlug.

 

[Absoroka]

Maybe cut a piece of paper to fit the lock mortise and clear all the operating elements of the lock. This might lift the lock enough to relieve the friction and not affect the spring or barrel?

 

[Phil Coffins]

Note how much of the short part of the main spring was reduced on this still working original.

 

[Flintandsteel]

If you can file a spring, you don’t have a spring. A file should skate across the spring if it’s hardened.

 

[TDM]

If you can file a spring, you don’t have a spring. A file should skate across the spring if it’s hardened.

Springs are tempered enough to be cut with a file. You just have to be careful. If the springs weren’t tempered they would snap just installing them.

 

[FlinterNick]

A quick note of filing a notch in the barrel. Assuming that most american made barrels are cut from 12L14 steel.

12L14 steel tends to be on the softer side of steels, notching an area in the breech isn’t a very good idea, for the risk of over doing it.

Cutting a dovetail and or drilling a blind screw hole isn’t a problem, however filing off too much on a 12L14 barrel can be done rather easily mistakenly.

You would want to attack the issue which is the spring, not the barrel.

Filing a chamfer on the spring should work, while maintaining the integrity of the spring as well.

 

[dave_person]

Hi,
You can take off from the barrel or the spring. The mainsprings on most commercially made locks are too strong anyway and grinding a deeper bevel on the upper leaf is easy and you are not likely going to ruin anything. My main comment, however, has nothing to with the spring. Anyone who would make and sell a gun with that kind of gap between the lock and barrel is a hack. Seeing that no effort was made to polish the inside of the lock or finish the mainspring confirms that. I suspect there may be many things questionable on that rifle so inspect it well.

dave

 

[DiMarco_Mercantile]

Thank you all for the input. So far I’ve reduced the gap down to about a 1/32”. I’m still working on getting the lock to sit as close as I can to the barrel. I chose to file away at the main spring slowly, would be much cheaper to replace it. I probably should’ve asked for more photos before I bought this, well at least I know for next time.

 

[DiMarco_Mercantile]

What is that hole in the barrel?

I assume you mean the touch hole. It’s slightly conical, the diameter of the outer hole about 1/8”, tapering down to 1/16”

 

[Rawhide67]

Yep, grind the barrel. One of the few acceptable uses of a Dremel tool on guns.

Nothin wrong with a little thin spot in the barrel.

 

[waksupi]

Nothin wrong with a little thin spot in the barrel.

Considering the expansion ration of black powder, I see no concern. It is a small section of the heavier breech area.

 

[Mr. Flintlock]

Nothin wrong with a little thin spot in the barrel.

Barrel $350.00, mainspring $35.00 you choose.

 

[Rawhide67]

Considering the expansion ration of black powder, I see no concern. It is a small section of the heavier breech area.

I may be overly cautious but I think.id avoid thinning the chamber area. Just my 2 cents. Especially when the spring can stand a shave.

 

[deerstalkert]

chances are that you will be working on the spring any way later. just do it now as it is needed.