Restoring percussion fowler - nipple and hammer questions

[steved]

I more or less completed my work to restore a Walker percussion fowler that my buddy Flint62Smoothie passed along to me after he received it as a "frequent customer" gift from his local gun store. The main challenge I encountered in this effort was to find a replacement nipple because the cone was long gone on the original.



The threaded base measures .290" in diameter. I tried to replace it with a .285 x 28 AMPCO nipple from Muzzleloader Builders Supply (MBS) - the closest I could find after an extensive Internet search. It seemed to thread right in with a little wobble, so the threads appear to be 28 but the diameter is a little too small. The nipple is tight when fully seated but the wobble on the way in makes me think it would be too dangerous to shoot. Does anyone know where I can find a .290 x 28 nipple, or would I need to drill and tap the bolster for a 5/16 x 24 nipple?

The other challenge was to find a replacement hammer for the back action lock since the original hammer is cracked.



Can a cracked hammer be fixed by welding or forging? I don't have any welding experience or equipment so if it is possible to fix I would send it to a gunsmith to work on. I found out by trial and error that it is not so easy to find a suitable replacement hammer for a back action lock even if you find one with the right throw. I ordered two from Track but found that the geometry of the tumbler was not correct for the square opening in the TOW hammers. I finally located at MBS a back action hammer with no opening and I fitted the hammer to the tumbler. (The replacement had a butt-ugly dog head design that I tried to make less ugly by filing off the dog ears) The problem is, the replacement hammer is not nearly as thick as the original one, so the tumbler shaft stuck out high above the replacement hammer. I made a spacer/washer by cutting the head off a .30-06 cartridge and drilling out the primer hole until it fit over the tumbler shaft.



Any input on my questions about finding a replacement nipple and fixing a cracked hammer will be greatly appreciate.

BTW - here are a few before/after pictures of the restoration

 

[Zonie]

I didn't have any better luck than you did when searching for a .290-28 threaded nipple.

Unfortunately, if you try changing the thread pitch you will need to remove all of the existing threads to assure your new size threads has full threads. It can't form full threads if the hole already has cut away material for the old thread size.

That means the minor diameter of the new thread will have to be larger than the .290 thread you currently have.

A 5/16-24 thread needs the unthreaded hole size to be less than .272 so your hole size is already too large for that size.

I don't think there's room for a 3/8" thread and there are no standard nipples with that thread size.

A possible solution is to either have special nipples made with a .290-28 thread or weld up the existing hole, redrill and thread it to a standard 1/4-28 nipple thread.

This too has its dangers.
Some of the breech plugs in days of old were made of cast iron and cast iron is very difficult to weld. If you go this route, be sure to have the welder check the existing breech plug by doing a spark test where he grinds just a little of the material away to see what kind of sparks it makes.

 

[Supercracker]

TOW sells nipples with oversized threads and the appropriate taps to dress up the breech threads.

I used them on my original and it worked like a charm. And I shoot it quite a bit. Of course, you'll have to always buy the nipples from TOW so order a couple at a time so you will have a correct spare.

 

[steved]

Zonie,

Thanks for the insight that it would not work to try to re-tap for 5/16. Did you end up finding a solution for your .290-28 nipple? Did you find someone to make one?

Supercracker

I checked TOW but the largest 1/4 x 28 oversize they carry is .275 and I didn't see a 5/16 or 8mm oversize listed on their website in case I wanted to fit a larger size nipple into the bolster.


Can anyone comment on the possibility to fix/weld a cracked percussion hammer?

 

[bpd303]

I have wire flux welded two hammers with no problems. Tig welding would work as well. The replacement hammer you have installed looks good and if it is stable, I don't think the spacer detracts from it. By the way thanks for the idea of using a cartridge case head to make the spacer.

 

[tiger13]

I dont see a reason why you could not oxy acetylene weld it either myself. I have used the process for ages with a filler rod. It is almost a lost art now.

 

[DickS]

The hammer could be welded.
Got a friend with a lathe? A nipple could be made to fit the threads exactly.

 

[ohio ramrod]

While chasing a fine thread on a lathe can be done if you have the right tooling, it is considered a last resort due to the difficulty of getting an accurate thread on such a fine pitch.I have made several "specialised" nipples before I retired but would not attempt it on my own lathe. Putting in a "helicoil" would be another option to consider. :idunno:

 

[steved]

The replacement hammer you have installed looks good and if it is stable, I don't think the spacer detracts from it. By the way thanks for the idea of using a cartridge case head to make the spacer.

bpd303: Thanks. The replacement hammer is stable but strikes a little too far to the right. I guess I can heat it and bend it a little left so it strikes the nipple dead center.

Gentlemen.

Thanks for advising me about the possibility to weld the original hammer. Would be nice to have if repaired and back on the fowler, giving me two options.