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Cleaning / Lubing Colt double action internals

8205 Views 44 Replies 10 Participants Last post by  RDak
Recently acquired a Colt OMT and wanting to know how to properly clean / lube internals. The trigger is very heavy / stiff and am wanting to make sure everything is as it should be inside.

First, I know that disassembly is not recommended. I know how to properly and correctly remove sideplate. Is there a way I can clean out and lube all the parts without further disassembly (than just removing the sideplate)? I am convinced that a good cleaning will improve the trigger. If this was a more recent gun, I would probably leave it alone. Being as how it was made over 70+ years ago, who knows what crud, or residual grease is caked onto the moving parts. While I dont mind shooting the gun in single action, it seems a shame for such a fine firearm to be at 50% capacity.

My idea (subject to change) is to spray out the inside of the internals with eezox to hopefully remove all crud and gunk. Then to gently blow out excess oil with air compressor. A light coat should still remain even with blowing it otut. Then I got some good grease from Brownells called Action Lube Plus in the mail today. I want to put this on the parts that should be greased.

First of all, is my idea of how to proceed a proper one?

Second of all, if it is, where I should I put the grease?
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I actually already have the book, and used it to make sure I was properly disassembling the revolver. Guess I didnt read far enough! Ill see what I can find in it.

Thank you again for your help-
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Just spent some good time in Kuhnhausen's book. Hes got some great ideas in there, and some areas I am going to have to check out.

One thing that jumps out at me as a possible contributing factor for the very heavy trigger pull is the mainspring. His book points out that if the tip of the bottom leg of the mainspring is too pointed, it might be dragging on the rebound lever. When I look at that, it looks like someone has messed with that tip, and it might need to be smoothed out, I didnt know how obvious this looked until I looked at the picture on my computer and had it enlarged.

A second observation I made is that it seems that the long part of the mainspring is abnormally straight...I see little or NO bend in its relaxed state. The replacement mainspring I saw on one of the parts websites showed some curve to it. Kuhnhausen addresses how to make adjustments to the mainspring (look surprisingly easy) but Im wondering if its better to start over with a replacement, or try adjusting this one. Thoughts anyone? Maybe these pictures will provide some clues to knowledgeable parties if some of my issues lie in the mainspring...
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That one doesn't look good, I'd be thinking of replacing it.

The "right" modification to the bottom front of the bottom leg is to lightly round it off and polish it. I've seen tuned guns from other smiths in which they put a very slight upward bend on the very end of the spring.

Personally, I thought the slight polish and rounding was less stressful for the spring.
My original spring was in good shape, but I didn't want to mess with it.
A good friend obtained a new Colt spring for me, and that's the one currently in My Diamondback.

BTW, here's the thread where I found the action procedure:
http://www.coltforum.com/forums/colt-smithing/29878-action-work-colt-diamondback.html
All good info. Thanks for the thread link, that's a good one.
If you decide to replace the mainspring here's a new reproduction one for the Official Police: (Maybe some other members can chime in and let us know if this mainspring would fit your OMT.)

Go to page 3, part #32.


Numrich Gun Parts Corp. - The World's Largest Supplier of Firearms Parts and Accessories
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While I would be curious to know if that would work for future reference, I dont think Ill need to pursue it. I called Jack First Gunshop yesterday and ordered a new mainspring. They are also replacement (not factory) but the friendly lady on the phone assured me I would never know the difference. I thought about ordering two, in case I wanted to experiment with one, or one went bad down the road, but she said they have hundreds in stock, and will simply have more made once they run out. Im excited to see how well it will work.
The Jack First Co mainspring will probably work fine. I have one in my Colt OP (1956).

With shipping they are a bit more expensive but no biggie in price difference.

Good luck!
Dfariswheel...resuce me!

Okay so my mainspring came from jacks first today. I put everything back together with the exception of the cylinder. I wanted to be able to dry fire it without causing any damage to cylinder as I wanted to see if the lube job and new mainspring fixed my stiff trigger woes. I pulled the trigger. Beautiful. Felt like a new gun. It felt like my trigger pull was reduced by 50%. I imagined myself shooting this gun with great joy.

Then came the fail.

I put the cylinder in. The cylinder will not turn more than once or twice because the bolt is not dropping, preventing the action from, well, acting.

Why wont the bolt drop? I thought maybe the screw holding it was too tight so I backed it off a little, nothing happened.

Should I tighten the screw even more? (I was a bit cautious with it as I can see how easy this screw would be to bugger.)

Does this have something to do with the rebound spring??

I checked Kuhnhausens trouble shooting guide, but Im not see a solution in there.

If I could get this one problem figured out, I could finally go out and shoot the dang thing!
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The bolt is powered by the tiny spring, check to see if it's in place. The screw in the bolt should be tight, but not to the point where you risk breaking it.

The bolt is activated by the rebound lever. Unless the pin at the rear that holds it in the frame is out of place, simply installing a new main spring shouldn't have affected bolt function.

Make sure the front of the rebound is properly in place under the hand. Often during disassembly the hand slips outward and the rebound slips off the ledge in the slot on the back of the hand. The rebound and thus the bolt will not operate correctly.

To check bolt function with the side plate off, put a finger on the hand to prevent it from slipping outward and out of place.
With the side plate in place just look up inside the frame as you operate the hammer.

In either case, the instant the hammer starts to move back the bolt should begin to drop.
You can view the operation of the bolt "tail" as the tiny triangle surface pushes the tail upward, which caused the front of the bolt to drop into the frame.

This should allow you see WHY the bolt isn't operating, which will likely be something out of place which is preventing the tail of the bolt to be engaged by the rebound.

When the hammer is cocked far enough, the bolt tail will slip off the rebound with a clean "click".
When the hammer is lowered again, the tail of the bolt should snap back onto the triangular surface on the rebound.
If something is out of place or "whatever", the tail of the bolt will not snap back onto the rebound, and the action will operate without operating the bolt.
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Okay, thank you so much. I will go through these points and see if I can diagnose what is going on. The spring is good, and the hand was being properly operated by the rebound lever, so I am thinking you are right about something else not being in place. Im wondering if it is an aspect of my assembly procedure.

I will view the operation of the bolt tail as you suggested and see why its not lifting.

To be continued...
Like Dfariswheel said, I would think most likely the rebound lever slipped off the proper place it sits under the hand ledge.

Same for bolt screw, just firm it up, don't over screw it.

If it functions fine with the sideplate off it should function well with the sideplate on IMHO. (The hand slipping off the rebound lever is a very common thing that happens when reinstalling the sideplate.)

Good luck!

ETA: Pay close attention to how Dfariswheel is saying the action functions, he is spot on, as usual, and you should be able to see what is or is not properly occurring.

In fact, I am making his response a sticky in the most useful posts thread.
Thanks RDak and Dfariswheel. As Dfariswheel suggested, I watched the action in progress to see what was going on. I made sure to apply pressure to the outside of the hand so that I would know that the rebound lever was not slipping out of the recess on the hand.

I then turned the gun over to look at it from the right side (side opposite of the sideplate). From this angle I could where the tail end of the bolt meets the triangular cam on the rebound lever. It is now obvious what is happening. The bottom of the bolt tail is not clearing the top of the triangle when the rebound lever lowers. Thus when the trigger is pulled, and the rebound lever goes up, it is not catching the bolt. It is very close to catching, but yet, not close enough. If I put a little pressure on the exposed portion of the bolt (I mean the bolt head that comes into contact with the cylinder) it is enough to push the tail end of the bolt upwards so that it clears the top of the cam.

I first made sure the bolt spring was properly seated, thinking maybe it was putting too much pressure on the bolt (not likely but thought I would start with a simple solution). That did nothing.

The second thing I tried to do was LIGHTLY polish the top of the cam to allow the bolt to clear. I must not have done much cause it did not fix it. I am nervous to proceed further. Here is a quote from Kuhnhausen's "The Colt Double Action Revolvers: A Shop Manual Volume I" page 105

"Old revolversmiths get an almost reverent look in their eyes when discussing this subject, and tell you in confidence, that rebounds are "touchy" and that if you are like the rest of us, you will probably ruin a few before you get the hang of fitting them. They are 100% right. Always go very slowly with rebounds, and double check your steps."

I can tell this one has been worked on before, whether it was from the factory, or someone else in the last 70 some odd years of its existence. I am guessing "someone else" as I compare it to pictures in Kuhnhausens book.

So here are my options as I see them:

1. Continue to attempt to modify the rebound lever in such a way that it will hopefully catch the bolt.

2. Order a new rebound lever and hope it doesn't require too much fitting.

3. Send it to someone like Cylidnder & Slide and be done with it. (Do they work on E frames?)

The action feel so much better now that it is lubed up and the mainspring has been replaced. Its frustrating because I want to get out and enjoy this old beauty. If a good thing has come out of this, I have become much more familiar with the inner workings of a revolver, and appreciate Colts meticulous fitting all the more.

Of the three options, I listed above, what do you guys think will be the best option?
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Repairs in order:

1. Send it to an expert for an expert repair.

2. Lower the rebound. This is shown and discussed on pages 102 through 106 of the Kuhnhausen manual, and the actual bending process is shown on page 164 and 165.

Pay close attention on WHICH WAY the rebound needs to be bent. It's opposite of what seems it should be bent.
If the rebound is too high and the bolt isn't resetting, you need to FLATTEN the rebound to lower it. Arching the rebound raises it.

Note that it doesn't take too much to affect bolt reset when it's close. Bend in very slight mounts to prevent having to bend it back and work hardening and possibly breaking the rebound.

What I found is that the less work you do on a bolt the better. Other than fitting the front to the cylinder notches and bending the rear tail to correct timing, it's best to not touch anything else.
One other point..... don't bend the tail while it's in the gun. Bolt screws can snap off in the frame if you bend while it's in the gun.
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Thank you much. I will take a look at that portion of the book and see if it is something I feel comfortable tackling. Hopefully a slight nudge will correct the problem and I will be up and running.... If that fails, off to the experts.
Dfariswheel, what if Dave just bent the bolt tip slightly towards the triangle so it could be "grabbed" by the triangle when initially pulling the trigger?

(Unless I am not reading the problem correctly?)
Bending the bolt tail will only work if that's the reason it's not resetting.
If even with the tail bent in more the bolt can't be picked up by the rebound, then bending isn't going to fix it.

This is one reason the old Colt action can make you crazy. The major problem is diagnosing exactly what the problem or problems really are, and not "fixing" something that isn't out of order.
Not to interupt, but, this started with the OP wanting to thoroughly clean his OMT and he still didn't like the pull so it went from lube to disassemble to a bigger problem and now maybe to Colt for repair? My caveat is I'm too OCD when I clean my Colts and I DO understand the need to feel your internals were clean and properly lubed BUT perhaps the disassembly could have been a little over the edge in this case. Gunsmithing an OMT isn't for the faint of heart unless you've got dfariswheel sitting at your kitchen table (as he's one person I'd trust to do the work). Yeah, I know some members think it's not rocket science and all that BUT...maybe it's brain surgery :p All this IMHO :eek:
Bending the bolt tail will only work if that's the reason it's not resetting.
If even with the tail bent in more the bolt can't be picked up by the rebound, then bending isn't going to fix it.

This is one reason the old Colt action can make you crazy. The major problem is diagnosing exactly what the problem or problems really are, and not "fixing" something that isn't out of order.
Understood.

Would you try that first though?
Best thing to do is LOOK.
Even if the bolt tail is bent away from the rebound you can see whether the bottom of the tail is above or below the ledge on the rebound.
If the tail is below the ledge no amount of bending of the bolt can correct that.

If the bolt tail is level with the ledge but too far away then and only then will bending help.
If the tail is below the ledge, "probably" the rebound needs to be lowered.
Again, these things can be difficult to diagnose.
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