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View Full Version : Possible issue with my new R/M conversion


tater134
July 7, 2010, 01:51 PM
Picked up a Cimmarron 1851 Navy Richards Mason conversion in .38spl not too long ago.Its a great shooter and Im really happy with it but there may be a possible issue involving the barrel wedge.This is my first open top revolver so hopefully you guys can help me out.Hopefully the way Im explaining this will make sense.Heres the issue:

The cylinder on the gun will bind up unless the wedge is pushed all the way to the left and the only thing keeping it in the gun is the screw on the side of the pistol because there is no friction inside the slot for the wedge with the wedge out this far.

When the gun is holstered like this the wedge gets pushed back into the slot which binds up the cylinder so that when it is unholstered you cant cock it without pushing the wedge to the left.(this definitely doesnt seem normal and is a major PITA)

Also with the wedge out to the left there is some noticeable left to right barrel wobble which cant be good for accuracy right?

Hopefully you guys understand what Im talking about and can help me out.If you need any photos to understand it better Id be happy to take some.

Dino.
July 7, 2010, 02:22 PM
You say "it's a great shooter", meaning you actually shot the gun with the wedge pulled out as you described? :eek:

You may need to have the wedge "fitted" or there may be issues with the arbor.
Either way, I wouldn't shoot the gun until you get it repaired.

JMO

mykeal
July 7, 2010, 03:16 PM
The problem is actually the arbor pin; it's too short. You need to shim the end of the pin a bit so that the barrel assembly bottoms out on the pin before the wedge slot in the pin lines up with the wedge slot in the barrel assembly. If the two wedge slots are lined up perfectly the wedge will not be effective in bearing the loads in the barrel assembly to the frame. In addition, as you have found, the barrel assembly will be too close to the cylinder.

I would suggest a bigger wedge, but that won't solve the problem of the wedge slots being aligned and the cylinder binding against the forcing cone.

tater134
July 7, 2010, 05:16 PM
You say "it's a great shooter", meaning you actually shot the gun with the wedge pulled out as you described?

I took it out and shot a box through it the day I bought it and it shot great.After I noticed the wobbly barrel issue I was surprised that I got any accuracy at all.I havent shot it since that.

tater134
July 7, 2010, 05:23 PM
The other thing Ive also noticed after looking at the gun closer is that it appears to me that the rear of the barrel where the forcing cone is doesnt appear to be milled off straight when looking at the gun from the side.

If I hold the pistol up and look at the light coming through between the cylinder and the forcing cone it appears that when the wedge is pushed in so its tight the top of the forcing cone is touching the cylinder and the bottom is not.Could that be the problem?Or is it just happening because when the wedge is pushed in the barrel is tilting upwards slightly?

sltm1
July 7, 2010, 08:48 PM
Couple of possibilities. 1st, arbort too short, maybe.....to check, take the barrel off the gun and remove the cylinder, then put the barrel back on sideways. When you rotate it down, it should match-up with the frame like when in battery, any overlap show's the arbor it too short as Mykeal suggested. Also, check the front end of the cylinder for levelness. I just fitted an R&D in an 1860. It rubbed on the outer edge because the center of the cylinder was a thousandth or 2 deeper than the outer edge. This will eliminate the top rubbing on the forcing cone with the wedge all the way in place. Also, "all the way in place", to me, means the wedge just barely protrudes on the side opposite the retaining screw. Locking it with the spring coming through shows a decidely poor fitting wedge. Good luck, and if you want me to R&D it for a year or so, no problem, Hell, I'll even cover shipping heh-heh LOL!

tater134
July 7, 2010, 10:14 PM
Thanks for the comments sltm1.Im going to take it apart tomorrow and check things out.By the way I just took a look at the pistol again and there is no spring on the wedge nor is there any place for one to be installed.

ClemBert
July 8, 2010, 07:45 AM
Have you considered contacting Cimarron about your problem? Sounds like either an exchange is in order or have them fix the problem under warranty.

denster
July 8, 2010, 09:25 AM
The problem, as mykeal stated, is a too short arbor. The best way to check with an Uberti is to measure the thickness of two #6 washers and then drop them in the arbor hole and reassemble the gun, no wedge, and measure the gap between the frame and the barrel lug with dial calipers or feeler guage. The difference between the gap and the thickness of the two washers is how much the arbor is short. You can then make a plug to correct.
On their percussion guns Uberti uses a tapered arbor fitting into a tapered hole to try to limit barrel travel, and it works after a fashion unless someone uses too much force on the wedge and ruins the nice fit. Then you need to address the arbor bottoming out in the arbor hole. The barrel, under ideal conditons, should go on no further than the point where the barrel lug meets the frame.
With the wedge. You want it to go through untill at least the radius on the end clears the far side. More is OK less is not.
We have been having a good discussion on arbor and wedge fit over on the high road forum that gives a lot more details. Check it out.

denster
July 8, 2010, 09:28 AM
One other point. With the 1862 police Colt redesigned the wedge and got rid of that annoying spring.

denster
July 8, 2010, 09:38 AM
One other comment. With the wedge out all the way to the left there is nothing holding the barrel on the gun but friction. Do not repeat do not shoot it this way.

tater134
July 8, 2010, 01:03 PM
Alright so I just disassembled my gun and did the arbor check by putting the barrel on sideways.There is overlap when the barrel is rotated down to the frame.It appears that either the arbor is too short or the arbor hole is bored too deep.The amount of overlap is about the thickness of a penny.(Gotta find my calipers to get an exact measurement)Ive thought about talking to Cimarron about the problem but I did buy this gun used so Im not sure if theyll be able to do anything for me.As of right now it looks like Ill have to make some sort of plug to correct the problem.

denster
July 8, 2010, 02:36 PM
The easy fix is to use the two #6 washers to get the exact dimension then you can likely find one of them that is within a thousandths or two of the exact right thickness. One that is a little too thick can be stoned down a bit then you can JB weld it to the end of the arbor. What you are experiencing is wear from the previous owner driving the wedge in to far and ruining the nice fit it had from the factory.