Home Forums Hunting & Shooting Handguns Understanding Colt's DA timing

I think the Colt�s DA revolver actions have been and remain highly mis-understood. Everyone seems to be an expert on Colt�s timing when in fact I think "everyone" is getting it wrong. In military tests the Colt�s DA revolvers consistently out did the S&W action, and contrary to popular lore, Colt�s are far from fragile; in fact, I consider the .41 frame (�I�) to be every bit as durable as the S&W N frame .357�s.

Here�s where the common mis-conception comes from. It�s the finger drag timing test. You slow down the cylinder with your thumb as you thumb cock your Colt�s DA revolver. The test goes that if one or more chambers don�t drop into the cylinder bolt, then it�s out of time. The problem is, it just isn�t so. True PERFECT timing would be that way, but you have to understand that the Colt�s DA revolver were never built at the factory to where they would pass that test in the first place. So it makes you wonder if the test is the correct test; I say it�s not. Certainly a gunsmith who is going to replace the hand on a Colt�s DA revolver would install it in such a way that it passes that test. He does so because he has the luxury of time that the factory fitters just didn�t have. But Colt�s was quite content to send out even Pythons that don�t� pass that test; why? Well it�s because the test really isn�t relevant. The second notch on the pawl ensures that when the trigger is fully pulled, the cylinder will lock up perfectly even if your gun doesn�t pass the thumb drag test. For a Colt�s DA revolver to not lock up with either pawl hook is exceedingly rare (even more rare than S&W�s going out of time), and at that point the gun is truly out of time.

The PROPER way to check timing on a Colt�s DA revolver is to thumb the hammer back, pull the trigger, then check for lateral movement of the cylinder. Typically there will be none, but on a worn pawl you may find a tiny bit, about what a S&W has. If you do that test, then turn the cylinder and hear it drop into the locking bolt, then the gun REALLY is out of time, and should be repaired. The same test covers DA timing; one size fits all.

I think of it in the same light as headspace gauges for a rifle. You have go, no-go, and field. In-between the go, & no-go is perfection; but if the rifle closes on a no-go but not a field, then it�s perfectly safe and usable; this is often the case for a military rifle. So when the Colt�s DA revolver doesn�t pass the thumb drag test (and most wont), the gun is still �in time� but in more of a �field� manner. It is still working exactly the way the factory intended it to work.

Kevin, when you say "drop into the cylinder bolt," do you mean "directly into the deepest part of the recess," or do you mean also onto the ramp that leads to the deepest recess? I've always assumed the ramp was also a reasonable place to drop.

I�m specifically talking about cylinder lockup, so into the locking notch.

That's just cool. I have a 1980 vintage Python and I've read the stuff about timing issues so I just did the test and the cylinder locked up TIGHT.

Then to compare, I a took a model 686 that's a few years old, did the test, and sure enough the cylinder wiggles just a bit. Then I repeated that with a 1967 model 19 and same thing.

There's no one who posts on the Campfire that I learn as much as from you Kevin. Thanks for the time you take to educate people like me.

Thanks, Kevin. It's good to know there's a definition of "really broken" on the other side of "not quite perfect." That will save me some worries as my Detective Special gets more use.

I own exactly one Colt revolver and it is an Officers Match 38 Special. Wonderful piece, wonderfully accurate and just plain fun to shoot, particularly with the greenhorns ;-). Wonderful DA and SA trigger and timed perfectly when the hammer falls. I own one and will only own one as there are fewer and fewer around that understand how to fix 'em if they need fixin'. But every sixguuner should own a DA and SAA Colt IMO (I still lack the latter). Kinda' like the M94 for us rifle boys. So, in summary, I will stick with my Smith's that do all the Colt does with parts and smith's well available if needed but a Colt, well is a Colt.

Very happy to help out. Let me know if you ever have any issues with your Python.

My diamondback and python lock up with the thumb drag test. My anaconda and cobra don't. I never much cared one way or the other because I don't shoot them that way. I figured the momentum of the cylinder turning when fired in either single or double action mode would take care of the lockup. On a side note, unless i'm mistaken, i don't think the cobra and anaconda cylinders lock down at trigger pull.

My complaint with the colts is many I've seen have the barrel screwed on too tight. Some enough that the front sight is canted enough to notice. Other times it's only noticeable when you look at the back of the barrel and take note of the amount of space on either side of the barrel rib relative to the front of the frame.

I've was once told one that the python and diamond back have barrels whose inside dimension is slightly smaller at the muzzle to "choke" the bullet. Any truth to that?

Djones,

The Anaconda and Cobra have the Mk V action, so they are very different and functionally are more like a S&W in many ways. The cylinders do not lock when the trigger is pulled.

I've heard rumors of tapered bores on Pythons, but I've never actually slugged bores to confirm or deny that claim. What I can tell you is this. The Python barrel is as accurate as any custom heavy barrel a gunsmith may install. They were made exceptionally well.

Yea the cobra certainly ain't no python, but of course, it's not intended to be. Hard to get a better break than the old "glass rod" feel of the python. As nice as the cobra and anaconda look, and they are beautiful, I find the hammer fall to be clunky. When I dry fire them free hand for practice, the hammer strike moves my sight picture. Even from a rest they don't seem to be as accurate as my Smiths. They're nice revolvers for sure, but I wouldn't give today's prices for one.

I used to use the thumb drag test when evaluating revolvers as a young man. I missed a lot of good deals before I quit letting that test make up my mind.

The first with that action was the Mk III�s and I thought they were good guns. When you dry fire them, yeah they do have a clunky sound, but there�s nothing clunky about them; they�re well made. The Mk III�s used sintered internals, and like any other time someone used a new technology in guns, everyone raised hell about how inferior sintered metal was, and every closet metallurgist told horror stories of what �could� happen with sintered metal. Of course if ANYTHING went wrong with those guns, even if it was a chip on the grips, sintered metal was to blame. Hey, I recall when many people called Rugers cast pot metal junk.

By the early �80�s, investment casting was beginning to become accepted; only took 40 years or so, but hey, we don�t want to rush things. So they switched to investment castings where were FAR less precise than the supposedly inferior sintered internals of the Mk III�s. As a result, the Anaconda�s and King Cobra�s are not nearly as smooth or slick as the Mk III�s. But hey, that�s what the market wanted. I just wonder how long it will take for people to get over MIM despite the fact that it�s been working very well for a good 20 years now.

Good for you Kevin, I will leave all those that don't lock up on the thumb drag test for you.