Colt Detective Special Timing

Here's my instructions for checking the older Colt action revolvers for correct timing:

CHECKING OLD MODEL COLT 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.
 
About damn time you showed up!
Where have you been?

Thought I was gonna have to carry this one all by myself. :)
Denis
 
For those who don't know him, D was born & raised in a wealthy family in Hong Kong, but left when the royal colony reverted to the Chinese in 1997.
He now resides in Singapore, where he operates two very successful airsoft manufacturing concerns, and is the holder of 17 patents in the industrial popcorn vending industry.

A lifelong student of the old Colt DA revolvers, D has an encyclopedic knowledge of the subject, and now spends much of his time in retirement sharing that knowledge with us on gun forums such as this.
His lovely wife, Camile, and his faithfull basset hound, Baskerville, are his constant companions.

Denis
 
I currently own three DA Colts, A 32/20 OP circa 1931, a Colt Marshal circa 1955?, Cobra, newish, no shroud. Use to own quite a few D frames 30 years or so ago...dick specials, diamondbacks, etc. Worked on them thru info from Skeeter Skelton articles, lengthening hands lightening springs, probably not Colt gunsmith approved. The 32/20 when I recieved it would allow the cylinder to roatate backwards with a little pressure. Took it apart and did some filing to the rear of the bolt and all was well. All my current Colt bolts do not drop into the cylinder notch with a thumb retarding rotation SA. They all lock up tight, (hand pushing notch against bolt), DA. They are all accurate particularly the 32/20 with my cast handloads. Not wanting to steal the thread,but would like to know if Dfariswheel knows how tough the OPs are. I have shot the heavy Skelton and Keith loads in the Marshal and the only reason I don't anymore because of the pain caused by factory grips...Am I on a ranting tangent?
 
I can tell Grant Cunningham knows Colt actions, how to work on them, etc but he sure does have a fancy way of saying that the Colt action is obsolete, and that it does not offer any real advantage over say a S&W action. I personally know of 3 Colt DAs that were out of time, a 1969 Python that I owned, a model 357 that I own now (same action as Python) and a Colt OMM from about 1954. I don't believe I was just unlucky, and I don't think it was because the oil and air filters weren't changed in these "Ferraris" either. I've had a few S&W problems as well, but much less frequently and at least one problem was from someone inside the gun. Don't get me wrong, I have a Colt collection and I really like them overall but I get tired of hearing about how great they are from the people who know far less than myself, when in reality, I collect S&W even moreso. I respect Cunningham's opinion when it comes to how a Colt works, or how to repair a Colt, but not for his opinion on Colts compared to other DA revolvers. Denial comes way before acceptance, as per Kubler-Ross.

According to these very generous analogies for Colt, when common sense is applied, these Colt DAs would surely still have a market following, and be very profitable, just like, ironically enough, both Ferrari and Rolls Royce still do. No one says "well I don't want one of them, they cost too much". The problem arises when, for example someone says "wow I'm never buying a Rolls Royce again because I can get the same luxury and quality, or even a little better from Cadillac". And that folks, is what happened to Colt.

I'm not a pistol smith, but as a collector, I have a good bit more than 5 or 10 of each, and I own them from all different eras as well. For my money, regardless of the Cunningham opinion on why Colt actions have some hiccups, its going to be S&W nearly every time. When he called S&W pedestrian, he lost some credibility with me personally. Funny how the "pedestrian" standards of S&W were not attainable by Colt, causing Colt to cease DA production. Even if he meant pedestrian meaning, more common only, it was a poor choice of words. Any Colt fan should look at S&W with the same respect and admiration, because to say the least, they are still around today. And if they were the Ferrari, and S&W the F150, Colt still failed miserably because at that point, they had zero domestic competition for a true higher end Korth-like American made DA revolver. Many Colt fans have trouble accepting the truth about their Rolls Royce (or Ferrari) of revolvers, or their company as a whole. If I had a $1 for everytime I heard some variant of: "man you don't understand, they stopped making DA revolvers because they cost so much to make, and were so awesome, that no one wanted them and they were not profitable but they were actually the best of all time but no one bought them. Don't you get it!"

Ya I do get it, I get it very well. Too well.

How common is this out-of-time condition? Does it happen from firing cartridges or dry-firing, or both?
Click to expand...

Also, the issues, rather imaginary issues that people have with Colts going out of time are often on medium frame guns, and more specifically I frame or perhaps E. I never read nor heard of any reliability or timing issues with the Colt D frame, for any model. I personally own a Cobra, a Detective Special and a Diamondback. I have few rounds through them for several reasons, but all work great. The D frame has a very different action than a Python, or other medium frame Colt, and therefor should not be placed under the same umbrella as the others. The Colt D frame was used for the Police Positive Special, Detective Special, and Diamondback. The D frame airweight was used on the Cobra, Viper, Agent, Courrier?(IIRC). The odds of wearing out a D frame Colt are not very good, esp considering how uncomfortable most snubs are to shoot. Also consider these are 38 special guns, and you can practice with 38 special but carry 38+P if you really want. Of course you need to make sure that the 38+P is appropriate for your specific Colt before shooting those in it. With standard pressure 38s, assuming the gun has no problems from the factory, the Detective Special should outlast any of us.
 
I sent an OP, a Trooper .357, and a DS to Grant, all for timing work.
My Python timing was corrected locally.

The timing issue extends across frame sizes & is inherent to the design.
The pressures of the ammunition used and the frequency of use will determine how soon the hand wears, but eventually it WILL wear, timing WILL be affected, and it goes downhill from there.
The hand performs two purposes in the V-Spring actions, on Smiths & Rugers it performs only one. That's why the old Colt hand is the major design weakness.

You see the timing issue arise more commonly in the larger Colt frames simply because people by & large shoot the bigger frames more. That doesn't mean the D Frame is any less prone to hand wear.

There's a reason why those guns are obsolete. Time & labor intensive to build, and they'll tend to require outside maintenance more often than a comparable Smith or Ruger with extensive use.

If you choose to accept a gun that has timing issues, it's your choice.
I choose not to shoot such a Colt.
A Colt that starts out properly set up will simply run longer before it needs a hand replacement than one that starts out with a short hand.
Denis
 
I can't be trusted at my local gun store.

I found a like-new Colt Detective Special from about 1976 and brought it home with me. It has obviously not been carried as the blue looks good, no grip rubs or anything like that.

I'll run Dfariswheel's test some more times, but it checked out pretty well, I thought, for my first time running it. The Bolt Drop Timing worked through several full cylinder turns, with one cylinder one time dropping into the slot itself rather than the ramp - the rest of the time into the ramp. The trigger stacks slightly towards the end of the pull, allowing me to know it's close to firing; as long as the rest stays in good timing I'll leave it like that. If it ever goes out of time, I'll probably have it adjusted to "no stack."

The only real concern I have is whether or not I've just bought another "too pretty to shoot" piece. Pics tomorrow.
 
Good luck with it.
Hope by the time it ever needs adjustment there'll still be somebody around who can do it for you. :)
Denis
 
For those who don't know him, D was born & raised in a wealthy family in Hong Kong, but left when the royal colony reverted to the Chinese in 1997.
He now resides in Singapore, where he operates two very successful airsoft manufacturing concerns, and is the holder of 17 patents in the industrial popcorn vending industry.

A lifelong student of the old Colt DA revolvers, D has an encyclopedic knowledge of the subject, and now spends much of his time in retirement sharing that knowledge with us on gun forums such as this.
His lovely wife, Camile, and his faithfull basset hound, Baskerville, are his constant companions.

Denis

On New Year's Day you're supposed to put the cork back in the bottle and sober up.

His name is Merlin and he's a black and silver Pomeranian.
 
Winchester_73,

My favorite snub loads have always been the standard pressure Nyclad, now owned by Federal, but I'd be willing to also try the Corbon DPX, also in standard pressure. The Nyclad is cataloged but hard to find, and the DPX is no longer cataloged. It's hard to find good standard pressure 38 Special loads.
 
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