Author Topic: Standing breech/snail, found design flaws. Need advice.  (Read 1913 times)

Offline Rolf

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Standing breech/snail, found design flaws. Need advice.
« on: July 14, 2020, 12:22:32 PM »
I have finished the standing breech and it is nice and tight, but I found some major design flaws in my Le Paige pistol project. In retrospect, should have drawn plans with the parts in scale 1:1 before starting. I did not think I needed to since I had the origial snail to copy.


This is the lock I had planned to use. When the hammer is in the fired position and placed in contact with the nipple, the hole for the lock bolt conflicts with the standing breech. If I move the lock rearwards to avoid this, the hammer cannot reach the nipple.


A second problem is the mismatch between the shape of the snail and the shape of the lock plate. The next picture shows the wreck that donated the barrel. The original lock plate has a gentle slope that follows the curve of the snail. The other lock plate has a much steeper curve.
 

The “new” lock plate will make a weak spot between the snail and the upper corner of plate with very little wood. It also looks strange.

 
I need to discuss possible solutions and hope for advice and inputs. These are the options I have thought of:
1)   Get a new lock that fits the snail. Problem with that, is I would have to design and make the lock from scratch. I do not think I have the skill for this.
2)   Make a new plug/snail that fits the lock. This plug would have to be without a standing breech. To avoid conflict with the lock bolt, the length of the plug can be max 18mm long.
        The plug I made is 23mm long without the standing breech.
3)   Use the barrel for a flintlock pistol. This is the easiest solution and right now the most tempting.

Best regards
Rolf
« Last Edit: July 14, 2020, 12:30:13 PM by Rolf »

Offline FALout

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Re: Standing breech/snail, found design flaws. Need advice.
« Reply #1 on: July 14, 2020, 12:38:53 PM »
Could you make a new lock plate  To match the old one and just use the internal parts of the lock you were gonna use?  Maybe then all you would need to do is alter the hammer as needed.
Bob

Offline Adrie luke

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Re: Standing breech/snail, found design flaws. Need advice.
« Reply #2 on: July 14, 2020, 02:09:22 PM »
Rolf

Maybe you can bent it a little bit.

Adrie



Offline L. Akers

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Re: Standing breech/snail, found design flaws. Need advice.
« Reply #3 on: July 14, 2020, 02:53:47 PM »
Rolf, there is no rule that says a lock has to be attached with a through-bolt.  Use a machine screw  threaded into the standing breech to fixture the lock.  I have seen this done on originals and have used this method of attachment myself.

Offline rich pierce

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Re: Standing breech/snail, found design flaws. Need advice.
« Reply #4 on: July 14, 2020, 04:05:55 PM »
Rolf, there is no rule that says a lock has to be attached with a through-bolt.  Use a machine screw  threaded into the standing breech to fixture the lock.  I have seen this done on originals and have used this method of attachment myself.

Sounds best to me.
Andover, Vermont

Offline Eric Kettenburg

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Re: Standing breech/snail, found design flaws. Need advice.
« Reply #5 on: July 14, 2020, 04:42:38 PM »
Yes, or weld up the original bolt hole, clean it all up and reshape the plate to fit the snail, then put an attachment screw or through-bolt wherever you want.  This depends upon how much room you have with the guts of the lock.
Strange women lying in ponds, distributing swords, is no basis for a system of government!

Offline Craig Wilcox

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Re: Standing breech/snail, found design flaws. Need advice.
« Reply #6 on: July 14, 2020, 05:10:21 PM »
Perfectly OK to drill the lockbolt hole through the lower part of the standing breech. Works to help hold the barrel in.
Craig Wilcox
We are all elated when Dame Fortune smiles at us, but remember that she is always closely followed by her daughter, Miss Fortune.

Offline D. Taylor Sapergia

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Re: Standing breech/snail, found design flaws. Need advice.
« Reply #7 on: July 14, 2020, 07:39:18 PM »
Rolf:  I think your best approach here is to weld up the hole and then re-shape the arc of the plate to better coincide with the snail's curve.  Prior to welding, take close up detailed photos of the engraving on the plate, because you're going to have to repair the engraving that gets damaged by the welding.  I wouldn't be surprised if the plate is case hardened too.
Be sure, when you are aligning the lock with the nipple, that you leave some throw in the hammer so that it is not at the bottom of it's throw when it hits the nipple.  You don't want the lock stopping against the tumbler bridle every time you fire it.  The nipple should be stopping the hammer's fall for the most part.  That will mean dropping the lock's position just 1/16" or so.  That might also allow a little more clearance for the lock bolt/standing breech clearance.
Choose a dense hard piece of wood for the stock, so that the wood between the snail and the lock is hard and tough.
D. Taylor Sapergia
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Art is not an object.  It is the excitement inspired by the object.

Offline Rolf

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Re: Standing breech/snail, found design flaws. Need advice.
« Reply #8 on: July 26, 2020, 11:27:49 AM »
Thank you all for your advice. I've decided to try and make a new breech plug/standing breech that fits the lock . I think this is possible , if the lock bolt is threaded into the standing breech. I have found pictures of a pistol with a very short plug. I've attached pictures below. As you can see, most of the shield is part of the standing breech and not the snail. This time I'm going to do a full scale drawing of the pistol before doing any metalwork. Welding up the bolt hole in the lockplate and reshaping it to fit the plug I made, would remove 3/4 of the bolster and there is not enough room for a new bolster. Bending the hammer would not lenghten it enough.

Best regards
Rolf


Offline Bob Roller

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Re: Standing breech/snail, found design flaws. Need advice.
« Reply #9 on: July 26, 2020, 06:59:38 PM »
Rolf, there is no rule that says a lock has to be attached with a through-bolt.  Use a machine screw  threaded into the standing breech to fixture the lock.  I have seen this done on originals and have used this method of attachment myself.

Yes,this is a fast and not unusual fix for this very small problem.Also that lock looks
like a high quality one and can you show the internals.I looked at the screw patterns
and I think I am right,
Bob Roller
Bob Roller
« Last Edit: July 26, 2020, 07:29:10 PM by Bob Roller »

Offline Rolf

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Re: Standing breech/snail, found design flaws. Need advice.
« Reply #10 on: August 02, 2020, 05:14:18 PM »
Yes,this is a fast and not unusual fix for this very small problem.Also that lock looks
like a high quality one and can you show the internals.I looked at the screw patterns
and I think I am right,

Bob Roller

Here is a picture of the internals. It has a four screw bridel and the lock plate is stamped J.Staton. Beautiful work.
Best regards
Rolf