Uberti open top questions

[Collo Rosso]

I know this is supposed to be for S&W's, but I'm hoping there's somebody familiar with Uberti (Colt) open tops that can give me some advise.
I've read about the to short arbor for the cylinder and mine's short by .072". If I add shims the barrel face meets the frame flush, but I wind up with .030" cylinder/barrel gap. Also the wedge no longer goes in the slot. Articles say to set the cylinder/barrel gap with shims, but if I were to do that the barrel face (lug, tab.. bottom piece that meets the frame with 2 pins) wants to be 10's of thousands of an inch past that point. Machine the barrel face and frame? Help!

 

[Kurusu]

You may try the Cas City forum. Pettifogger will be your man, he wrote the article on fixing the arbor on open tops.

 

[Collo Rosso]

You may try the Cas City forum. Pettifogger will be your man, he wrote the article on fixing the arbor on open tops.

Pettifogger is a gunsmith. He's free with the information on correcting the arbor length but nothing about correcting the tolerances you off set by correcting the arbor length. Other than shipping him the gun...

 

[Hondo44]

I've read about the to[o] short arbor for the cylinder and mine's short by .072".

Yes, I know Open Tops.

Please explain the affect of the above. What problem does it cause?

You're not talking about the gas ring attached to the front of the cyl being too short are you?

Where are you talking about adding shims? Front of the gas ring?

Do you have a proper headspace between recoil shield and rear face of cyl of ~.063 - .065"?

I have two Cimarron Uberti Open tops and owned 3 others with no such problem.

 

[Milton]

Sounds like you have too many shims or at least they are too thick.I went through the same thing you did and ended up buying some very small thin washers and fitting them until the arbor just fit snug.That should give you a tight arbor and do nothing to the cylinder gap.I did have to thin one washer(I had to fit three) so that I got a snug fit of the arbor but my cylinder gap did not increase.The washers I used were 0.39 inches in diameter and 0.035 inches thick.

 

[P.44]

Here -Thanks to "old fogey" ! / scroll down to reply #26-
you may find something helpful about the "short arbor fix":
Need Help Selecting A Colt Style Gun

Good Luck !

P.44

 

[Collo Rosso]

New out of the box I had to fabricate a durlin punch to get the wedge out. I wound up supporting the barrel on plastic blocks and using a 26 oz. ball peen with the durlin to drive the wedge out. Before I played with any shims I tried to put it back together and there was no tapping the wedge back in. Smacking it with a weighted plastic mallet wouldn't do it. That can't be right. Playing with shims I never forced anything, at most tapping the wedge with a plastic screwdriver handle.
The arbor thing is that the barrel lug meets the frame, the wedge goes in but the arbor never bottoms in its hole in the barrel. Supposedly this causes the barrel to never be in the same place every time the gun is assembled, and after a while the gun shoots loose. The wedge is not supposed set any tolerances, simply hold the gun together. As the frame and barrel meet below the cylinder the arbor is supposed to bottom in its hole. Mine would need a .072" shim in the hole to do that. Hope that explains it.

 

[Milton]

The wedge on my Open top was very hard to remove and when it went back it did not go in like my 1860 Army.Instead it just did go through the barrel and arbor with the wedge just barely sticking out on the ejector side of the barrel.I still believe you could drop two 0.035 inch thick flat washers in the arbor hole in the barrel and then cut a round shim 0.002 inches thick to add to the two washers to get the arbor bottomed out in the hole.That should make the arbor fit snug but not change anything concerning the cylinder barrel gap.

 

[Hondo44]

The usual way to do this is to drill and tap the front end of the arbor for a set screw or pan head screw. Blue locktite will keep it in place and still allow adjustment for wear later on.

 

[Collo Rosso]

The usual way to do this is to drill and tap the front end of the arbor for a set screw or pan head screw. Blue locktite will keep it in place and still allow adjustment for wear later on.

Yes, read about that also. That was going to be a final solution but never got there. Playing with shims first, I thought I'd see where my tolerances are and go from there.
Thinking about this today I called Cimarron. Spoke with a rep and when I told him about how I got the wedge out and it not wanting to go back in he said "that's not right". They're sending a shipping label, so I guess I'll let the "mother ship" have at it and see what I get back.
Thanks for the replies.