Swiss 7.5 ordnance M1882 - lockup tuning

[junkdude]

I'm looking for some advice from the antique gurus regarding tuning up a 7.5 Swiss ordnance revolver.

The cylinder does not lock up as tight as I think it should when in battery. There is approx 0.015 rotational movement. I'm sure it will shoot fine but I'd like to have it a bit tighter. Is this little bit of movement normal with these pistols as the rest of it is built and runs like a swiss sewing machine.

It appears as though the pawl needs to be pressed laterally towards the loading gate, this makes the cylinder lock up tight. If I access to pawl when the revolver in battery, and slip a 0.015" feeler gauge in between the pawl and the outside frame, it produces the necessary force of the pawl against the ratchet and lockup is nice and tight.

I was planning on cutting a piece of feeler gauge to fit and silver solder it onto the side of the pawl, this would press the pawl towards the loading gate. Is this the correct approach or is there some other way of tuning this up that I'm missing?

 

[mooncoon]

are you sure that the cylinder is in line with the barrel when the pawl is shimmed? Is the hole in the frame large enough for the shimmed pawl to fit through?

cheers mooncoon

 

[trevj]

When you are done mucking with it, I'll give you fifty bucks for the remains. I'll need to see pictures first, though.

Have you downloaded the 'book' on them yet?

If you don't have a way to determine how well centered the cylinder is with the barrel, you have little or no business mucking about with any one component.

Make a complete new part. Gage plate (Starrett flat ground stock) is cheap and you won't #### up the original part if it does not work like you expected. Scabbing a part onto another small part with silver solder is gonna play holy hell with the heat treatment of your pawl, and it'll be the next thing you will replace anyway, esp. if the cylinder is misaligned to one side when fired. Holding two small pieces together while simultaneously silver soldering them then quenching them from red heat... limited odds of success.

Cheers
Trev

 

[mooncoon]

Holding two small pieces together while simultaneously silver soldering them then quenching them from red heat... limited odds of success.

If you leave the piece to be added considerably oversize, alignment is often not a problem because you grind the excess away after the part cools. Also while the combination is still red hot, pour water over them to harden them and then of course draw the temper to your desired temperature or colour.

That does not address the alignment of the cylinder but the shimming is doable

cheers mooncoon

 

[apu]

If this is a new gun to you before you start messing with things take her apart as much as you can and give it a good cleaning and lube, I have had more than a couple of antique handguns who on the surface appeared to have timing issues and all it took was to clean a few decades of blackpowder residue.

 

[junkdude]

Thanks for the ideas.

The cylinder is not perfectly aligned with the barrel, but it is when sideways pressure is placed on the pawl, it's just a wee bit off. I was going to make a mandrel to find out what the true alignment between barrel and cylinder should be.

The gun is very clean, almost looks as though it's never been fired.

There is enough room for a wider pawl, it seems the best suggestion so far is to make a new pawl. I'm not terribly concerned with loosing the heat treatment if it is silver soldered, which I don't think will happen as silver solder melts well below carbon steel annealing temperature (I was thinking of soldering, not brazing), and if it did loose it's temper it could always be re-treated. I do like the idea of making a new piece instead of modifying the original anyhow, but first I'll need to get the piece out and see how complicated the backside is.

 

[trevj]

I don't know what steel temperatures chart you are using, or what silver solder, but any silver solder I have used that was worth the name had a melt temperature way higher than was needed to draw out all or at least most of the hardness. Red or near red heat.

Make the new part.

My best bet would be that you are going to have to find the balance between the cylinder stop (bottom center rear of cylinder, acts on the tapered notches) and the pawl that advances the cylinder and should hold it in place as the trigger is pulled.

Does it lock up tight when the trigger is pulled, as opposed to having play when cocked, but no pressure on the trigger?

There was a Belgian guy that was spamming the forums with sales adds for his series of How-to E-books. If you search the web, you can find it has been uploaded in several locations. The cross section drawings are handy for figuring out how the parts work together.

Cheers
Trev

 

[jethunter]

There may not be anything wrong with your revolver. I don't have a lot of experience with the swiss M1882, but IIRC the mechanism does not lock up fully when the hammer is at full ####. It locks and indexes when the trigger is pulled all the way to the rear. The final movement of the trigger moves the pawl so that it tightens against the ratchet, locking and indexing the cylinder into position as the hammer drops.

To check:

1. pull the trigger all the way to the rear (lower hammer manually, avoid dry fire).

2. Now you can check the cylinder lock up by trying to rotate the cylinder with your free hand while still holding the trigger all the way back.

Old webleys, the french M1892 revolvers, and many of the revolvers designed in the 1800s worked like this. They do not lock up solid at battery like modern revolvers.