Old DA COLT Experts...


July 30, 2009, 03:39 PM
...Please tell me if this is correct

I have an old Colt Official Police 38 and the timing appears to be off only with the single action. If i pull the hammer back quickly, the cylinder locks up tight. If i pull the hammer back slowly the cylinder doesnt lock. However as soon as i put any pressure on the trigger the cylinder locks and the hammer falls. Is this "normal" timing for a colt?

Thanks for the help guys.


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July 30, 2009, 03:57 PM
My Official Police does not really lock up until the trigger starts to move. At that point, the cylinder is firmly locked into place and is properly aligned with the forcing cone of the barrel. From what I have read, that is correct functioning.

Others can provide more (and better) information.

July 30, 2009, 04:08 PM
Far as I have seen...this is how they are.

Mid-Frame and Big-Frame also...same way.

If the Hand is worn, and hence, become too short to rotate the Cylinder far enough to lock, then the Hand may be 'stretched' or, replaced, according to the judgement of one's Gunsmith.

July 30, 2009, 06:53 PM
Thanks for the responses. I took it to a gunsmith earlier today and he seemed to think it wasnt functioning correctly....but he wasnt too familar with colt.


July 30, 2009, 08:29 PM
If when you slowly cock the hammer, the cylinder doesn't lock fully, its out of time.
This IS NOT in any way "normal" and unless its a factory defect, Colt's did not leave the factory like this.

While it IS out of time and not correct, the old Colt action will lock up when the trigger is pulled unless its pretty bad.
AS LONG as it does go ahead and fully lock, its safe to shoot, but beware a gun that gets so bad it doesn't lock when the trigger is pulled. The gun will then be firing in an unlocked position, with off-center primer hits and probable bullet metal spitting out the barrel/cylinder gap.

Failure to lock is a defect, but its also a sign of normal wear on the Colt action and a sign the gun is due for a tune up.

July 31, 2009, 03:17 AM
My understanding is that a colt cylinder should lock solidly with very little or no play when the hammer is cocked, my DS does.

July 31, 2009, 07:57 AM
Thats wierd. None of my D-frames are rigid when the hammer is cocked. Even my NIB unfired 1969 Cobra. Only when the trigger is pulled does the cylinder become welded shut :) Kevin.

Thomas Garrett
July 31, 2009, 08:02 AM
I checked my Official Police and both of my OMM's, the cylinders lock immediately SA or DA. All 3.

Old Fuff
July 31, 2009, 08:23 AM
Cylinder carry-up (full rotation between chambers) is mostly controled by a second tooth or step in the hand. It is a unique Colt feature that goes back to the 19th century, and to work perfectly requires 19th century craftsmanship and fitting - something seldom seen today.

While a worn hand can cause the timing to go south, one often overlooked reason is if the crane gets sprung by someone flipping the cylinder in and out. I have often corrected the condition by using nothing but a hammer... :what:

Well O.K., not the kind of hammer you're thinking of. :evil:

But anyway, If thumb-cocking your Colt doesn't fully rotate the cylinder do look into the possibility of a sprung crane. Also in later years not all Colts left the factory perfectly timed because of one reason or another they lost the best of their skilled workers.

It should be noted that in most later post-1970's models Colt dropped the two-step hand.

July 31, 2009, 10:58 AM
Thanks for the info guys. It seems there are a few that think it may be ok and a few that say its not ok. Obviously, im leaning towards not okay...otherwise id be shooting it already:D I really dont want to send it in to do a few hundred dollars worth of tuning. I only paid $265 for it at cabelas. I will, however, try to locate a good gunsmith in the wisconsin/illinois area. Anyone know of one?

Btw, i detail stripped the gun. The crane arm is not bent. The hand has some shinny spots where its been rubbing and the top tooth seems to have a slight arc on it (probably due to the circular motion of the cylinder and rubbing against the ratchet.) Anyone suspect that it may be the mainspring (v-spring)? It has plenty of spring tension (flew across the room), but the gunsmith at gandermtn said it could be that. Id like a second opinion.

Thanks again

Old Fuff
July 31, 2009, 11:58 AM
but the gunsmith at gandermtn said it could be that (the mainspring). Id like a second opinion.

Seems highly doubtful. Through some linkage it does put forward tension on the hand, which keeps it against the ratchet. But to make a difference it would have to be so weak that it likely wouldn't set off a primer.

Be careful when it comes to gunsmiths. There are very few left that have any real experience with these older double-action Colts.

Doug b
July 31, 2009, 12:27 PM
Dbar111 These folks www.ahlmans.com rebarreled my Python and tuned it.Done an outstanding job and the price was right.They're not in Ill. or Wis. but real close.

July 31, 2009, 12:55 PM
While a worn hand can cause the timing to go south, one often overlooked reason is if the crane gets sprung by someone flipping the cylinder in and out. I have often corrected the condition by using nothing but a hammer...

:D Gotta beat those heads--err, cranes--into the right shape.

July 31, 2009, 01:08 PM
If when you slowly cock the hammer, the cylinder doesn't lock fully, its out of time. I tried this will all six chambers on my 1947-vintage Official Police. The results were the same for all six chambers.

On each chamber, the cylinder bolt/stop pops up into the cylinder leade just before the chamber is properly positioned. As the hammer reaches full cock, the chamber is aligned and the bolt is locked into the notch in the cylinder. At this time, the cylinder can be wiggled a bit side to side (perpendicular to the bore axis), very similar to what one sees on a modern S&W revolver. If a bit of pressure is applied to the trigger, the cylinder can no longer be wiggled; it is locked as firmly as one of my Freedom Arms revolvers.

Is my revolver out of time?

Old Fuff
July 31, 2009, 04:19 PM
No, it's out of time if the hammer is cocked and they cylinder hasn't rotated enough to that the bolt has engaged the notch.

If the hammer was cocked, but the cylinder locked vault-door solid you couldn't pull the trigger far enouch to release the hammer.

Jim K
July 31, 2009, 06:08 PM
That whole action is tricky and a bit hard to analyze. Cocking the hammer drags the trigger along, and the hand is attached to the trigger. The "top hand" (the tip of the hand) starts the cylinder moving just after the rebound lever cam has pulled the cylinder bolt out of engagement. As the cylinder rotates, the "bottom hand" (the lower tooth on the hand) engages the next tooth on the ratchet. In order to cock, the hammer has to raise the sear of the trigger enough to clear the hammer notch, then drop down into it. (This setup looks like the S&W system, but the positions of the notch and sear are different.)

When the trigger clears the hammer, it raises the hand enough to cause the bottom hand to force the cylinder fully into engagement and the bolt drops into its notch. Then the hand drops down slightly into the hammer notch. Pulling the trigger then raises the hand but the cylinder is locked in place and there is just enough gap between the bottom hand and the ratchet to allow the trigger to move and disengage from the hammer. The bottom of the hand engaging the ratchet tooth not only locks the cylinder if it is not fully locked, it also acts as the trigger stop.

It is a complex system and many (I could even say most) Colt revolvers will not fully lock up in SA if the cylinder is held back while the hammer is being cocked. This is, IMHO, a problem that is more theoretical than practical, since the cylinder will rotate that last bit and lock when the trigger is pulled, while the hammer is falling.

Now, the purists will say that it shouldn't be that way, and I will agree. But I sold a lot of Colt revolvers and I would guess that 80% (at least) of them were not "right", straight from the factory.


July 31, 2009, 07:08 PM
The Colt action was known as the "Bank Vault" action due to it locking up the cylinder tightly WHEN THE TRIGGER IS PULLED.
If you simply cock the gun and don't pull the trigger the cylinder won't lock tightly in place.

As above, if the cylinder locking bolt doesn't drop into the locking notch on the cylinder, the action is NOT operating right, whether it left the factory that way or not.

Here's my instructions on how to check an old Colt action for proper timing.
Note that tis covers the older Colt's like the Official Police/Python and the Detective Special/Diamondback.
It DOES NOT cover any of the later Colt's like the Mark III/King Cobra, and it does not cover the S&W/Ruger etc.
Only the old Colt action is supposed to lock up tightly when the trigger is pulled. This is NOT a valid test for S&W, Ruger or any other revolver. They are not intended to lock up tightly when the trigger is pulled.


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.

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.

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.

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 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 before the hammer reaches full cock.

Have a smooth trigger pull, which does "stack" or get heavier as the trigger is pulled.

August 1, 2009, 08:03 AM
That is amazing information D. Thank you so much for sharing that. Mine are performing exactly what you have written. Thank you again! Kevin.

Old Fuff
August 1, 2009, 08:52 AM
I wondered when dfariswheel was going to show up... :cool:

His description is right on target. It should also illustrate:

1. That it took experienced, skilled craftsmen to put them together.

2. Why making them in a 21st. century manufacturing economy isn't viable.

August 1, 2009, 09:56 AM
I checked my Official Police per the procedure provided by dfariswheel, and it appears my Colt is just fine. It may be on the verge of having the hammer reach full-cock before the bolt engages the cylinder notch on one chamber. It did it once, but I could not get it to repeat. Nevertheless, I will keep an eye in it. The condition is not bad for a sixty-two year old revolver.

The old guns represent excellent value when compared to today's offerings. A used Official Police is less than a new S&W M10, and the Colt exhibits a lot more workmanship. If someone was to make the Official Police today, I am guessing MSRP would be over 2,000 USD due to the amount of labor involved in getting it right.

August 2, 2009, 12:14 AM
When I went to Colt armorers school the procedure described by dfariswheel is how it is done.

Jim K
August 2, 2009, 12:27 AM
One thing is worth noting about that "bank vault" lockup. Since it is achieved by the bottom of the hand forcing the cylinder around against the bolt (cylinder stop), if the bolt, the notches, or the bolt cutout in the frame is worn, the hand can force the cylinder past proper alignment and result in shaving lead. It takes a lot of wear, but I have seen old police guns that did exactly that, so I don't automatically praise the Colt lockup.


Old Fuff
August 2, 2009, 08:50 AM
... if the bolt, the notches, or the bolt cutout in the frame is worn, the hand can force the cylinder past proper alignment and result in shaving lead. It takes a lot of wear, but I have seen old police guns that did exactly that, so I don't automatically praise the Colt lockup.

True, which is the reason Colt recommended having revolvers regularly checked and serviced - somewhat like an automobile. Unfortunately this is harder to do now because of the lack of experienced and qualified Colt-smiths.

While hand/ratchet wear can cause chamber/bore misalignment, the combination of the Colt "bank vault" lockup combined with a sprung or bent crane makes the condition much worse. An old Army Special once came my way that was so misaligned that the barrel was cracked at the back. I brought it back to perfect timing and chamber/bore alignment by doing nothing more then fix the crane.

At the beginning of the revolver sub-forum a checklist written by Jim March is posted. While some of it doesn't apply to Smith & Wesson, Ruger and Taurus revolvers, the part on checking chamber/bore alignment is dead-on for older Colt's. If you are interested in buying these revolvers make a point of reading it.

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