1923 Colt Police Positive Special Bolt/Cylinder catch replacement

[54ball]

IMG_0087 by Travis Brown, on Flickr
At the bottom right is my Colt Police Positive Special in .38 Special.
It dates to 1923. It's still in time and it still locks up tight.

The bolt/cyinder catch is worn. This allows the cylinder to rotate backwards when the gun is not cocked. I can see that the bolt is rounded off especially on one side.

I have found a bolt for an early Detective Special which should be the same part.

I almost messed up and ordered a Police Positive bolt. The Police Positive and Police Positive Special use different bolts.

Have any of you been into a Colt Police Positive Special? Do you have any suggestions?

It sure is a sweet handling gun. It's really my favorite. Hopefully I can get it fixed up.

 

[Greyman50]

Have any books with exploded views of pistols and revolvers? Don’t think replacing the bolt would be a big deal.

 

[Ameshawki]

My advice is to stop. Colt lockwork of that era requires hand fitting. The chances of the parts just dropping in are slim and none. On top of which the parts you bought are probably already worn. Colt lockwork is a watchmakers nightmare. Everything is counter intuitive. There are smiths out there that will still work on them (my local guy will do it if he's in the right mood) but they are getting few and far between.

Smiths are much easier to work on.

 

[DWalt]

The DS and the PPS parts should interchange I’d try the swap. My previous repair attempts on Colts have worked OK, but I have Kuhnhausen’s repair manual.

 

[2152hq]

Most people find removing the mainspring the most difficult part as well as re-mounting it.
Don't be tempted to use a pliers to compress it.
You can easily remove and reinstall with just your fingers.

Once the V mainspring is out, the rest of the parts come out easily.
The cross pin holding the rebound arm is about the only thing you have to drive out.

Leave the hammer block safety parts in place if you want to, they are in the frame behind the hammer.
But notice how the very small pin on the trigger engages the linkage to operate it so to make sure you re-engage upon reassembly.

The cylinder bolt is in recess in the frame under the trigger.
Once the trigger w/hand is liftet out of the frame, the bolt is clearly visible.

The small screw holding it in place is removed. The bolt will not go anywhere as it will still be sitting in the recess under some spring tension from the tiny coil spring that gives it it's power.
That spring sit's in a pocket in the lower edge of the bolt,,you can just see it when the bolt is in place.

Remove the bolt carefully by lifting it up and free of it's recess. Watch for that small spring,,keep that for the new bolt.

Wether your 'new' bolt operates and fit is correctly won't be known till you get it in place and re-install at least the trigger, rebound arm & hand.
With those parts and using your fingers to mimic mainspring tension down on to the rebound arm , you will engage the new bolt with the rebound arm and see if the timing is correct.

Then there is the fit of the bolt itself into the locking notches.
There's lots to check and do. Don't be tempted to quickly adjust one part to make things work.
That usually leads to other things not working and down the line it goes.

 

[dfariswheel]

I was a Colt mechanic.
My best possible advice is to buy the Kuhnhausen Shop Manual on the Colt DA Revolvers, Volume One.

This was written as a training aid for new pistolsmiths, and shows all Colt work as done by the Colt factory.
As above, fitting a Colt cylinder bolt is NOT intuitive or simple. They require fitting in several areas, and bending to correct timing.
The manual will save you a lot of time, buying extra parts, and aggravation..........

The Colt Double Action Revolvers: A Shop Manual Volume 1 by Jerry

Jack First precision manufactures new Colt "D" frame bolts, both the early and later types. This is the best way to go because you're starting off with a factory new type part that hasn't already been altered to fit a different frame........

Colt D bolt, early #154-27

Colt D bolt, will need fitting #154-56076

 

[DWalt]

There is always a little bending on the tail of the locking bolt necessary to get it to lift and fall at exactly the right time. But don’t do it with the bolt in place. If you look at how everything works together, you should be able to figure it out. Take care to not lose the little spring and screw.

The bolt should begin to release just at the instant the hammer starts to move back, and should stay lowered until the next cylinder bolt slot nearly lines up, then it snaps into place. The bolt should not be allowed to drop between cylinders.

I have never had any significant difficulty in removing and replacing the mainspring. I recommend installing a new mainspring, as they do weaken with age and can cause misfires. They can be bent to restore strength, but at least fo me, that is not a permanent fix. New springs are available for the Python, OP, Trooper, etc., I don’t know about availability of new springs for the DS/PPS.

 

[54ball]

Wow! Thank you all very much. I should have asked here before I ordered my part.

 

[54ball]

My advice is to stop. Colt lockwork of that era requires hand fitting. The chances of the parts just dropping in are slim and none. On top of which the parts you bought are probably already worn. Colt lockwork is a watchmakers nightmare. Everything is counter intuitive. There are smiths out there that will still work on them (my local guy will do it if he's in the right mood) but they are getting few and far between.

Smiths are much easier to work on.

I was afraid of this.

 

[54ball]

Most people find removing the mainspring the most difficult part as well as re-mounting it.
Don't be tempted to use a pliers to compress it.
You can easily remove and reinstall with just your fingers.

Once the V mainspring is out, the rest of the parts come out easily.
The cross pin holding the rebound arm is about the only thing you have to drive out.

Leave the hammer block safety parts in place if you want to, they are in the frame behind the hammer.
But notice how the very small pin on the trigger engages the linkage to operate it so to make sure you re-engage upon reassembly.

The cylinder bolt is in recess in the frame under the trigger.
Once the trigger w/hand is liftet out of the frame, the bolt is clearly visible.

The small screw holding it in place is removed. The bolt will not go anywhere as it will still be sitting in the recess under some spring tension from the tiny coil spring that gives it it's power.
That spring sit's in a pocket in the lower edge of the bolt,,you can just see it when the bolt is in place.

Remove the bolt carefully by lifting it up and free of it's recess. Watch for that small spring,,keep that for the new bolt.

Wether your 'new' bolt operates and fit is correctly won't be known till you get it in place and re-install at least the trigger, rebound arm & hand.
With those parts and using your fingers to mimic mainspring tension down on to the rebound arm , you will engage the new bolt with the rebound arm and see if the timing is correct.

Then there is the fit of the bolt itself into the locking notches.
There's lots to check and do. Don't be tempted to quickly adjust one part to make things work.
That usually leads to other things not working and down the line it goes.

Wow!
Thank you for that detailed response.

 

[54ball]

I was a Colt mechanic.
My best possible advice is to buy the Kuhnhausen Shop Manual on the Colt DA Revolvers, Volume One.

This was written as a training aid for new pistolsmiths, and shows all Colt work as done by the Colt factory.
As above, fitting a Colt cylinder bolt is NOT intuitive or simple. They require fitting in several areas, and bending to correct timing.
The manual will save you a lot of time, buying extra parts, and aggravation..........

The Colt Double Action Revolvers: A Shop Manual Volume 1 by Jerry

Jack First precision manufactures new Colt "D" frame bolts, both the early and later types. This is the best way to go because you're starting off with a factory new type part that hasn't already been altered to fit a different frame........

Colt D bolt, early #154-27

Colt D bolt, will need fitting #154-56076

Thank you so much. I know where to get my parts now.

 

[54ball]

I also want to than DWalt and Greyman50.

I have to get the book and the new parts so it may be a while.

I know the bolt is worn but I wonder if a new bolt spring might cure the issue?

 

[dfariswheel]

There's no way of knowing that without actually installing a new spring.
As a possible aid, here's my instructions on checking the original Colt DA actions for correct timing...............

To check Colt timing:

BOLT RETRACTION AND "SNAP BACK".
Open the cylinder and look at the small "lug" in the bottom of the cylinder window. This is the cylinder locking bolt.
Cock the hammer, and watch as the bolt retracts into the frame and pops back out.
The bolt MUST begin to retract THE INSTANT the hammer begins to move.
There MUST be NO (ZERO) hammer movement possible before the bolt starts to retract.
The bolt should retract smoothly with no hesitation until it's fully retracted, then it must pop back out with a clean "snap".
There should be no hesitation, and no amount of "creeping" back out.

CYLINDER UNLOCKING.
Close the cylinder.
Use your left thumb or fore finger to again cock the hammer, closely watching the cylinder bolt as you SLOWLY cock the hammer.
As the hammer comes back, the bolt will retract away from the cylinder.
The bolt must retract far enough to unlock the cylinder BEFORE the cylinder begins to rotate.
If the bolt is still slightly engaged with the cylinder lock notch, the cylinder will be attempting to turn while still partially locked.
This produces a "catch" or "hard spot" in the trigger pull and will damage both the bolt and the cylinder lock notches.
This often appears as metal "pulled out" of the lock notches, with rounded off and burred notches.

BOLT DROP TIMING.
Continue to cock the hammer, LIGHTLY laying your right index finger on the cylinder just enough to prevent "free wheeling".
Watch for the bolt to drop back onto the cylinder. WHERE the bolt drops is CRITICAL.
The bolt MUST drop onto the leade or ramp in front of the actual cylinder notch.
If the bolt drops too soon, (in front of the notch ramp), it will mar the finish of the cylinder.
The bolt should drop into “about” the middle of the ramp.
If the bolt drops late, (farther toward the actual locking notch) the revolver may display "cylinder throw-by".
In this condition, during double action shooting the cylinder may rotate PAST the locking notch, and fire in an unlocked condition.
It's the nature of the Colt action, that a hesitant or jerky trigger pull by the user can induce throw-by in even a properly tuned Colt.
The Colt trigger should be pulled with a smooth, even pull, with no sudden jerks at the beginning.

CYLINDER LOCKUP.
Continue to pull the hammer back and both watch and listen for the bolt to drop into the cylinder lock notch.
The bolt must drop into the actual lock notch before or just as the hammer reaches full cock.
The most common Colt mis-time situation is the hammer cocks before the bolt drops into the lock notch. (Hammer is cocked, but cylinder isn't locked).
In this condition, with the hammer fully cocked, you can push the cylinder slightly, and you will hear the "CLICK" as the bolt drops into lock.
In my experience, most Colt's leave the factory with the bolt dropping a little late into the leade, but usually wear in to correct timing.
If the bolt drops onto the cylinder early, no real problem, but there will be extra finish wear.
If the bolt drops late (closer to the lock notch) the cylinder may "throw by" or rotate TOO far in double action and this can cause off-center primer hits and firing while unlocked.

Each of these checks should be done on EACH chamber. All of these checks are better done individually. In other words, do the bolt retraction check on all six chambers, then do the bolt drop test, and so on.

A properly tuned Colt will:
Have a smoothly functioning bolt with no sticky or hesitant movement.

Unlock before the cylinder begins to turn.

The bolt will drop onto the middle of the ramp.

The bolt will drop into the lock notch just before or as the hammer reaches full cock.

Have a smooth trigger pull, which does "stack" or get heavier as the trigger is pulled.
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Note that the old Colt Police Positive and Police Positive Special/Detective Special use the same action parts.
The only difference is in the length of the frame and cylinder to allow the PPS to use longer cartridges like the .38 Special.