Melwin Hulbert questions.

[Oceantop]

Hello,

I have two issues on a Merwin Hulbert 1st model, cal. 44-40 (Winchester 73). The gun has seen very little use and is in perfect order except for two (major) flaws.

1: The cylinder arbor has been broken just where the slide groove for the barrel begins. It has been repaired, apparently by a gunsmith for it is nicely done. However it is a week spot and we will make a new arbor from scratch. The reason is that I have failed to come across any spare ones.
The real question is: I have used so much force I dare, but it will not unscrew. The lock screw in the back got easily out. I suppose the arbor shall unscrew clockwise (normal rotation). I cannot see anything that should prevent it from coming loose. I have not tried heating since I have no idea how it will affect the nickel finish.
Any ideas how to get it loose?

2: Another strange thing with the gun is that the trigger seems to be too ?low?. When entering half cock the firing pin is still about 2mm inside the recoil plate. This prevent a normal loading of the cylinder since the firing pin is then hitting the cartridge rims and stops rotation.
I believe perhaps a small piece of the trigger has broken off when or if someone has used brut force when in half cock?. There are quite a bit of extra travel the hammer can do when fully cocked. Quite sufficient to overcome the problem of the firing pin sticking beyond the recoil plate.
To fix this I see two options: One is to put a weld (TIG?) in the half cock notch of the hammer, and file a new notch in the proper place.
Two, is to lengthen the trigger using the same method. But that will ruin the hardening I suppose.
What would an experienced gunsmith do?

Best regards
Oceantop

[Colt Fanning]

Howdy,
Problem 1.  Drill it out.
Problem 2. Solder a shim (Grade 8?) into the half cock notch.
Regards
Colt

[DJ]

Not a gunsmith by profession, but have messed with Merwins in the past.  The arbor should unscrew after the set/lock screw comes out.  Since it has been repaired, it is possible the gunsmith did something to make it more secure, such as a supplemental locking pin, solder, or loctite.  Since you've checked thoroughly, it is probably not the first one.  It is possible the other 'smith used Solder and locktite, which are usually defeated with heat.  You might look carefully to see if you can find any residue or heat coloring that might suggest one or the other.  Loctite's website says red loctite will yield to 500 F degrees.  Solder has a wide range of melting temps, depending on the type.  I don't know what 500 F might do to your nickel plate.  As an alternative and probably much more time-consuming option, since you're replacing the arbor anyway you might be able to take the cold route by cutting it off, center drilling it, and using a screw extractor to get it out.  If you can't access it from the front to extract it, if you cut the arbore off flush, I think you can extract it through the rear (I haven't looked at a Merwin with that in mind, so you should check the dimensions to make sure).  Failing that, you could continue drilling with larger drills until just short of hitting the threads and then collapse the thin shell of the arbor and then work it out.  If the shell is still stuck in place (which pretty much confirms solder or loctite), and you still don't want to heat it, you should be able to clean it out with a properly sized tap.  This "cold route" could end up being a labor of love, so be prepared to spend lots of time and most of your patience.

Regarding the trigger/hammer fit, you should try to figure out which one has been shortened or broken and fix that one.  I suspect the hammer half-cock broke and  your gunsmith predecessor fixed it by cutting a new notch without first adding replacement material.  That would explain the hammer being too far forward and would suggest the weld-and-recut method to fix it.  If you do that, make sure you don't set the renewed half-cock notch back so far that the locking bolt rises up and locks the cylinder at half-cock.  Of course, it might be the trigger, so  you need to check, but the ones I have looked at all seemed to be the hammer.

Be patient and good luck!

DJ

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[Oceantop]

Thank you both for helpful hints.

1: I have carefully looked for any additional locking methods of the arbor, there are none (that I can see). No evidence of solder or ?chemicals? either. Before drilling out I will first try larger tools.
The repair is done more than 70 years ago and previous owner never fired it.

2: It does not look like the hammer has been touched and a new notch made, but I wouldn?t bet.
The reason I suspect the trigger to be broken is the relatively long travel the hammer can do after fully cocked. I go for a new half cock notch as you suggesting.

Thanks again.
Oceantop

[Oceantop]

Last:

I finely took a chance to secure the frame of the Merwin Hulbert in larger vise and used a 25?? Norwegian style pipe wrench. The arbor finely started to move, and came out nicely.
I have not figured out the type of threads yet, but I was quite surprised that the threads was so fine pitched.

Oceantop