Excessive endplay on Colt Detective Special

Hoptob · Apr 15, 2009

I am looking for advice how to best fix excessive endplay on 3rd generation Colt DS (1973 manufacture). This gun has 0.004" bc gap and 0.005" endplay; Kuhnhausen manual shows maximum allowed endplay as 3 thousands. The gun is otherwise in a perfect working condition and I would like to have it fixed.

I enjoy some minor gunsmithing and have done similar work on S&W. However procedure described in the manual is beyond my skills and tooling. It turns out that fixing endplay on a Colt requires access to collar stretching fixture and to hydrolic press. I don't have either. Alternatively one can replace and re-fit the cylinder and the ratchet.

My questions are: is it really necessary to have 0.005" endplay fixed? If it is, can you recommend a good gunsmith? I don't know anyone locally, in Seattle area, who works on Colt revolvers. Maybe someone here knows if Colt Inc. is still offering gunsmithing services for their revolvers.

Thank you for your advice,

Mike

dfariswheel · Apr 16, 2009

The only "fix" for the Colt's is the collar stretch method.

Replacing the cylinder and ejector is expensive and still requires a master pistolsmith to do it right.
Happily, Colt still repairs the Detective Special.

Send it in to Colt. They'll inspect your gun and send you an invoice listing the things needed, and the cost.
Once you pay, it usually runs about 30 days until it ships back to you.
When it comes back, they'll have fixed it like new again.

You're allowed to ship the gun direct to Colt, and they can ship direct back to you.
The only bad part: It has to go by UPS, FedEx or another private shipper, NOT by US mail.
UPS and FedEx insist the gun be shipped by the most expensive and fast method, usually around $30, or so.
Many USP Stores will NOT ship a pistol, you have to go to a UPS depot.

Hoptob · Apr 16, 2009

That's exactly what I will do. Much obliged, Dr. D.

Mike

bountyhunter · Apr 17, 2009

Originally posted by Hoptob:

My questions are: is it really necessary to have 0.005" endplay fixed?

According to the expert who was lecturing me in another thread, it is. According to him, the Colt reputation for internal lockworks that easily get knocked out of time and need expensive repairs is that the colt design requires that the endplay be kept minimal. The front to rear motion of the cylinder batters the hand and associate parts.

And, therefore, SW shooters like us who are used to guns that can tolerate a bit of play without self destructing just don't give colts the maintenance they deserve.

Anyway, that's the story......

dfariswheel · Apr 17, 2009

The internal lock work on the Colt doesn't get torn up by end shake.

Like S&W, Colt or any other revolver, a cylinder with end shake starts battering the ejector and frame.
If you let it go far enough, you'll start getting "ratchet chatter" or ejector impact marks on the frame, and if bad enough, the cylinder can start to impact the rear of the barrel.

The problem is, with S&W you can let it go longer and when you have to fix it, you can stretch the yoke barrel and/or add some washers.
Due to the design, the "fix" for Colt is to stretch the cylinder collar, and you can only stretch them so far and no farther without cracking.
Let it go too long, and the only repair is a cylinder replacement which is a lot more expensive.

Then too, Colt specs were always held to a closer tolerance than S&W, and S&W has been letting specs slide more and more.
As example, Colt always held that barrel/cylinder gap of over .008 was out of spec and needed repair.
S&W used to do the same "back in the day" but lately has been telling customers that .010" and even 012" gap is "in spec".

Same thing for end shake. Colt always said that anything over .003" needed repair. S&W lets it go a lot farther.
Then too, the S&W repair is a lot easier and you can do a lot more than with Colt's.

It's not that Colt is "weak" or S&W is "stronger", it's just the differences in design.

bountyhunter · Apr 18, 2009

Originally posted by dfariswheel:
The internal lock work on the Colt doesn't get torn up by end shake..

I'm no expert on colts, but the source I was referring to (and paraphrasing) thinks he is...... anyway, he seems to think end shake is dangerous to colts.

http://www.grantcunningham.com...python_delicate.html

There's another measurement to consider: at rest, a Colt cylinder should move front-to-back no more than .003" (that's 3/1,000 of an inch.) This is - in the absolute worst case - about half of the allowable S&W movement!

Now, let's say a S&W owner, used to their looser standards of cylinder lockup, buys a Colt. He goes and shoots it a bit, and the hand (which probably has a bit of wear already, as he bought it used) is approaching the normal replacement interval. He checks his gun, and finds that the cylinder has just the slightest amount of movement when the trigger is back, and half of his S&W's longitudinal travel. Heck, he thinks, it's still a lot tighter than his Smith so it must be fine to keep shooting it.

WRONG! It's at this point that he should stop shooting, and take it to an experienced Colt gunsmith to have the action adjusted. Of course, he doesn't do this - he keeps shooting. The cylinder beats harder against the frame, compresses the ratchet (ejector), causing the hand to wear even faster, and the combination of the two leads to a worn bolt. If left unchecked, the worn bolt can do damage to the rebound lever. When it finally starts spitting lead and misfiring, he takes it in and finds to his astonishment that he's facing a $400 (or more!) repair bill, and perhaps a 6 month wait to find a new ratchet.

Hoptob · Apr 18, 2009

When I first checked out this gun I did of course look at the endshake. But not being familiar with Colts I made a mistake - checked it the way it's done on S&W and Ruger, in full lockup. Cylinder was tight and I was satisfied. This is probably a common mistake these days when Colts are getting scarce -- Grant mentions it in his article.

Later, following Dr. D. advice, I got Kuhnhausen manual and became more familiar with Colt procedures. Manual states clearly that endplay should be checked with trigger in it's forward position, i.e. not in lockup. This makes perfect sense because on DS only hand pushes cylinder forward in the lockup. Forces of the shot will move cylinder against hand pressure until it hits back of the frame; it will then bounce forward and hit front of the frame. When I checked endplay with hammer down it was 0.005".

To clarify, I don't think 0.005" is a okay on any revolver - Colt or S&W. Noone needs a loose cannon bouncing in the frame window. Especially if one likes to play with hot loads... I can't find S&W spec for endshake but recall that it was no more than 0.004" and preferably 0.001-0.002". The only reason I asked was in hope to avoid time and expense involved in fixing it. As Dr. D. said if it was an S&W I would just fix endshake myself and not think twice about it; in fact I would do it long before it reached 0.005". Unfortunately it's not that easy on Colts.

The upside is that Colt's gunsmith will look it over, fix whatever needs to be fixed and give this 36 y.o. gun another 36 years of good service.

Mike

dfariswheel · Apr 18, 2009

I may argue the finer points of the Colt DA with Cunningham, but I won't argue his skills or knowledge.

He's one of the very few Master pistolsmiths around these days who really know and "understand" the Colt DA.

People ask me for recommendations for Colt repairs, and I only recommend the Colt factory and Cylinder & Slide Shop and that's because I've seen their work.
I seldom recommend Cunningham only because he opens his waiting list only every year or so, so he usually turns people down.

If he says the Colt action can be damaged by end shake, he bases that on his extensive knowledge as a professional Colt gunsmith.

Onomea · Apr 20, 2009

Very classy response, Dr. D.

Hoptob · May 24, 2009

Originally posted by dfariswheel:
Send it in to Colt.

The gun came back from Colt all fixed up. BC gap is 0.006" (cylinder pushed back); endshake 0.001".

Colt also adjusted the hand, turned out that I pinned it a bit too much. Interestingly, they adjust DA timing such that in a very slow pull the hammer falls just before (not after) the bolt locks.

<span class="ev_code_RED">Thank you for good advice, Dr. D.!</span>

Mike

Excessive endplay on Colt Detective Special

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