Inquisitive Idiot

[BlackRock52]

I'm told there are no dumb questions but...(see title)
I have acquired a percussion BPML whose hammer is severely corroded in the base of the cup....very deep elongated pit. In discussion with those who know, buying a new hammer cheaper than a repair. That said, can I simply remove the screw at the hammer base and replace with the new hammer? Things won't come flying out??

 

[IanH]

The hammer should have a tapered, square hole through it that wedges on the tumbler shaft that comes through the side plate. The screw you see just holds the two parts together, it is a friction/ wedge fit that does the work of holding the two parts together. You will need to remove the lock, use a mainspring vise to compress and remove the main spring from the lock, then remove the bridle screws that hold the bridle to the inside of the lock plate. The bridle is a support bracket for the inboard end of the tumbler so it doesn't wallow out the hole in the side plate. Once all that is done, you will need to make a brass punch with a square tip that fits into the square hammer hole, support the lock plate, and drive the tumbler through the plate so it pops off of the hammer.

 

[BlackRock52]

The hammer should have a tapered, square hole through it that wedges on the tumbler shaft that comes through the side plate. The screw you see just holds the two parts together, it is a friction/ wedge fit that does the work of holding the two parts together. You will need to remove the lock, use a mainspring vise to compress and remove the main spring from the lock, then remove the bridle screws that hold the bridle to the inside of the lock plate. The bridle is a support bracket for the inboard end of the tumbler so it doesn't wallow out the hole in the side plate. Once all that is done, you will need to make a brass punch with a square tip that fits into the square hammer hole, support the lock plate, and drive the tumbler through the plate so it pops off of the hammer.

Awesome being a member here.. thank you so much!!

 

[TDM]

No, things will not come flying out when the hammer/cock is removed. But, in most cases, you can’t remove it by just removing the external screw. The lock requires removal and disassembly down to the bare tumbler. The tumbler can be knocked loose from the hammer/cock with a square punch, hammer, and the tumbler safely inside a socket large enough to hold it and still give support to the lock plate. As always, photos of the problem help quite a bit in finding a solution.

 

[deerstalkert]

be sure to not lose the screw. they are a pain to replace. be sure that the punch you use is only slightly smaller than the square hole in the hammer, if it is much smaller you run the risk of peening the threads for the above screw. do mess up the threads and either have to refresh tap them , or try to thread the screw back in and the shank of the screw snaps off from the torque of the buggered threads.
doing this may cause you to get your mouth washed out with ivory soap by the better half.
don't ask how i know.

 

[Phil Coffins]

And note where each screw was removed from, most times the sear screw is different than the bridle screw. Put them each back in the same place it was removed from.

 

[rich pierce]

It’s not straightforward to find a percussion hammer that:
1) has the same exact “throw” or distance from tumbler axle hole to the nipple striking surface in the cup
2) has the square hole indexed exactly the same as what you have now
3) has a square hole close to the right size and not too big.

 

[French Colonial]

I think I would try to take the hammer off and then fill the pit with some good solder

https://www.amazon.com/Solder-SILVE...18-spons&sp_csd=d2lkZ2V0TmFtZT1zcF9tdGY&psc=1

 

[appalichian hunter]

Or take the hammer off and weld up the damage and then re-shape the nose where it contacts the cap.

 

[IanH]

Or take the hammer off and weld up the damage and then re-shape the nose where it contacts the cap.

That's what I would do, but I have the equipment and skills to do so.

 

[Grenadier1758]

The Track of the Wolf online catalog has full sized photos of various locks. As @rich pierce notes, finding a replacement hammer is not easy unless you know the manufacturer and the lock is still in production. Even then parts change as original molds wear out and designs are updated.

@BlackRock52, do you know the manufacturer of your lock?

Solder would be too soft, even silver solder.

 

[longcruise]

Use a drill bit kinda like a mill bit and mill it out. It might not be too deep to be functional especially if you can find a long necked nipple.

 

[Jaeger]

And note where each screw was removed from, most times the sear screw is different than the bridle screw. Put them each back in the same place it was removed from.

It helps to take a close up picture with your cell phone of the inside of your assembled lock before you disassemble it!

 

[appalichian hunter]

If you decide to take the lock apart, I suggest a mainspring vise, and perhaps a small gear type puller to remove the hammer. You should be able to find a small gear puller at harbor freight. Your life will be much easier. Main spring vises can be found at the different muzzleloading dealers, Larry Calahan makes a very good one.

 

[Gtrubicon]

I'm told there are no dumb questions but...(see title)
I have acquired a percussion BPML whose hammer is severely corroded in the base of the cup....very deep elongated pit. In discussion with those who know, buying a new hammer cheaper than a repair. That said, can I simply remove the screw at the hammer base and replace with the new hammer? Things won't come flying out??

What gun are we talking about? An original or contemporary.

 

[BlackRock52]

It helps to take a close up picture with your cell phone of the inside of your assembled lock before you disassemble it!

Sage advice -- however, I do not have a cell phone -- ditched it and life is better
But getting a predemolition image makes great sense

 

[BlackRock52]

What gun are we talking about? An original or contemporary.

Pedersoli built in 2007
Smoothbore - 20 Ga SxS
Both hammer cups discovered to be badly pitted when I cleaned out the fouling. Left > right

 

[BlackRock52]

That's what I would do, but I have the equipment and skills to do so.

An acquaintance suggested steel reinforced JB Weld and a dremel to shape after curing...don't know if he was serious or not
If that fails then replace

 

[IanH]

An acquaintance suggested steel reinforced JB Weld and a dremel to shape after curing...don't know if he was serious or not
If that fails then replace

That was actually my first thought, wouldn't hurt to try. JB can do some amazing things sometimes.

 

[Sam squanch]

The factory my brother worked in ran off of JB weld. The first action of the maintenance crew was to JB weld it. Those guys would inject it into their veins if they could have…..