Model 10-7 Crane doesn't fit Cylinder

[postoak]

I bought a Model 10 off of Gunbroker and it worked fine but it needed refinishing so I sent it off to be reblued (they wanted it unassembled). They did a good job on the reblue and I didn't get around to reassembling it for a while. Now that I have, I noticed the the bolt plunger and spring were missing. I bought replacements off of eBay and proceeded with the reassembly but I'm stuck now because the crane won't go all the way into the cylinder -- it stops about 1/10 inch short. I did some searches here and found out the crane has a serial number and I checked and mine didn't match the frame serial number, however it could have been that way before but seems unlikely because it fit before. Am I going to be able to have a gunsmith fix this or should I try ordering a new crane? If they are serial number matched wouldn't I have a risk that the new crane wouldn't fit either? Can you even order new cranes? What serial number would it have?

 

[armorer951]

Work numbers, or "assembly" numbers usually appear on the back of the body of the yoke, and the same number will appear on the grip frame of the revolver. This keeps the parts identifiable and together during assembly and fitting.

Does the yoke go fully into the frame without the cylinder, and does it conform to the yoke frame cutout properly?

If the yoke appears to fit the frame properly, it's possible that there may be some debris either inside the yoke cavity in the cylinder, or inside the yoke.

If the parts are cleaned and cleared of debris and the problem persists, I would contact whoever did the refinish work and explain what has happened. They may be able to help with a solution. Another customer obviously received your yoke by mistake, and you received his. (or hers)

Replacement yokes can be purchased from vendors like Jack First, or Ebay. The new yoke will need to conform to the -7 (dash 7) configuration so you'll need to source one from that vintage if possible. Most likely, some fitting of the new/used yoke will be required.

Smith and Wesson could also help by fitting a new yoke to your revolver, although there may be slight finish differences.


Carter

 

[postoak]

Thanks, the issue is with the crane not going all the way into the center shaft of the cylinder; it goes all the way into the frame. I think there must be a raised area in the central shaft of the cylinder (that is, the shaft has a smaller ID at the back end) I think the crane is bottoming out on this smaller ID step.

But maybe I'm wrong about this. I'll have to recheck this in the morning.

 

[armorer951]

The yoke cavity inside the cylinder is the same diameter all the way to the bottom. I'm suggesting there might be debris left behind during the refinishing inside the yoke cavity in the cylinder, which would prevent the yoke from going fully to the bottom like it should. Just a possibility to check and rule out.

If you have already reassembled the cylinder assembly, you might also double check to see that the components in the cylinder assembly have been installed in the correct orientation and order.

Carter

 

[Retired W4]

The fact that the refinisher wanted the gun disassembled by you seems a little odd to me. I would have asked WHY before I handed it over. I have had guns reblued that I disassembled before I gave it to the guy doing the reblue but I chemically stripped the parts myself and took responsibility for reassembly.

 

[postoak]

I wanted to confirm that the yoke shaft that is hollow is bottoming out on the back side of the central shaft near the rear of the cylinder. If a gunsmith decreased the length of the yoke shaft then it would go all the way in and that may be the easiest way to resolve this. Of course, it is always possible that the cylinder I sent in isn't the one I got back, but this seems unlikely.
Also the center pin I got back is bottoming out on the ledge inside the extractor before it can project through the back of the extractor. I ordered a different one from eBay that fits properly. The raised ring on the center pin they sent back is 0.700" from the rear of the center pin whereas the one I got off of eBay that works has the ring 0.800" from the rear of the center pin.

I am not going to contact the refinisher as it has been too long for me to believe they have my parts any longer. I just won't have anything to do with them anymore.

 

[postoak]

Armorer951 - I just saw your last post. If the yoke cavity is what I think it is then it is smaller diameter at the rear end. It has to be because it is the diameter of the extractor shaft whereas most of the cavity is the diameter of the OD of the yoke. Or am I not understanding you? I took calipers and measured the yoke cavity depth to the rear lip. It is 1.425". The yoke shaft is 1.488". This is why the yoke won't go in the last 0.063". I looked and the yoke cylinder is completely free of debris.

What components in the cylinder assembly? Do you mean the extractor, the extractor spring, the center pin, the center pin spring, and the extractor rod collar? I've done that assembly multiple times and it is all correct.

 

[armorer951]

yoke

Sorry for the misunderstanding. I was referring to the yoke cavity in the cylinder. I thought there might be some debris down inside the cylinder that was preventing you from inserting the yoke down into the cylinder fully.


Does your yoke barrel look like the one in the photo below? I'm wondering if the refinishers might have sent you the wrong yoke back, one with a gas ring on it. The one below is from my 10-7, and does not have a gas ring on the yoke.

Cylinder with gas ring in the other photo.

 

[postoak]

I believe my yoke looks just like the one in your photo. What length does that one measure from the end to the abutment and what is the depth from the front of the cylinder to the ridge inside the yoke cavity?

 

[armorer951]

The yoke barrel is 1.490" from the bearing end to the collar. The interior from the end of the barrel to the point where the opening narrows for the extractor rod is 1.485".

Carter

 

[postoak]

Huh, well that's confusing. I was expecting something like 1.45"/1.45". I measured the length of the cylinder and compared it to the length of that on a 10-5 and they're about the same. I guess I'll disassemble my 10-5 extractor and yoke assembly and compare those measurements to the 10-7.

 

[postoak]

Okay, here's measurements.

Yoke shaft length on 10-5 1.485"

Yoke shaft length on 10-7 1.492"

Cylinder length on 10-5 1.562"

Cylinder length on 10-7 1.545"

Yoke cylinder depth to step down at rear on 10-5 1.485"

Yoke cylinder depth to step down at rear on 10-7 1.422"

Also, it probably doesn't matter, but the yoke shaft on the 10-7 has a varying diameter. About .7 inches from the front, it increases a few thousandths, then after about .25" it goes back to the original diameter (looks like) for about 1/16th inch and then it increases a little more at the front end.

 

[postoak]

Okay, I took it to the gunsmiths today and after quite a bit of head scratching we figured out what was wrong. The replacement center pin I bought from Numrich to replace the incorrect one that the bluer sent back turned out to have its own problem. The center pin spring didn't work -- it was too long. Since I had bought an extra one of those from Numrich, also, he cut it down bit by bit until we could get the center pin to retract fully, which allowed the cylinder to close shut easily.

However, it won't open back up. The problem is that this new center pin is too short at the front and it isn't pushing the locking bolt forward enough for it to clear the end of the extractor rod.

 

[steelslaver]

A small thin piece of metal like a feeler gauge should slip between tooth and end of rod and allow you to open it. If not you should be able to force the tooth back with a dental pick. If the center pin is just a small amont short trimming the outer rod will take care of it


The center pin should come flush to rod tip when you press portion of pin sticking out of the center of ejector star flush. Easy to check with cylinder assembly out of the frame. Just press rear of cylinder on a hard flat surface and look at end of rod. Just a tiny bit of stick out is good