Cobra - Cylinder won't stay locked **PICS ADDED**

[grizzlyblake]

I posted last week in the Revolvers section about this problem but now think it's more smith-related. I bought an old worn Cobra from Numrich on Gunbroker a while back and now realized that the cylinder won't stay locked. It clicks into place but takes only a small bit of pressure to pop it out. I ordered a replacement cylinder latch spring and spring guide and replaced them this afternoon, and the problem is no better.

The cylinder and frame have different serial numbers - does this mean that I have a mismatched gun that just won't line up true? I can't see any other obvious worn parts or anything. The cylinder latches in and the timing and whatnot seems fine but when the trigger isn't pulled it's easy to push out the cylinder without touching the latch.

[Alk8944]

Check the center of the extractor, where the latch pin engages. I have seen Colts that appear to have the cylinder "flipped" closed so much that it has beat the extractor to death and the center hole was badly wallowed out to the point that it was conical. This would easily cam the lock pin out of engagement it it was pushed on. The center hole should be perfectly cylindrical except for a slight bevel.

It is possible that the crane is sprung to the point that the latch pin doesn't engage properly too.

[grizzlyblake]

Looking more I believe that the latch AND the hole in the extractor are both worn to the point that they are conical, allowing the cylinder to slide the latch pin back out of the way. My DS has a crisp hole and crisp shoulders on the latch pin and it locks up very tight.

Are these parts that I can replace myself if I order them?

I'm assuming this gun is no longer safe to fire, is that correct?

[dfariswheel]

Not safe to fire if the cylinder is popping open.

Colt didn't put serial numbers on cylinders. Do you mean the crane the cylinder is on?
If the crane has been replaced, God only knows what problems it may have.

You can replace the latch pin easily, but not the ejector.
Ejectors are VERY much hand fitted parts.

First, you can't buy a new ejector only used. Colt has new ejectors but will not sell one unless they install it. (Which is the smart thing for you to do).
Used ejectors usually won't work, and often can't be used at all because they were already altered to fit to a different frame.

A new ejector has to be fitted to the cylinder to align with the chambers properly.
Then the rear face has to be precision surface ground to set the head space.

After that the following has to be adjusted for:
Barrel-cylinder gap.
Cylinder end shake.
Barrel-chamber alignment on all chambers.
Timing on all chambers.

Smart move: Send it in to Colt for a new ejector. Buying a used ejector and attempting to fit it is usually a waste of money.
This is where the big difference between revolvers and automatic pistols becomes clear.
Automatic parts can usually be installed with minimal fitting.
Revolver parts ESPECIALLY the old Colt action revolvers have almost entirely hand fitted parts. Almost nothing drops in.

[grizzlyblake]

Sorry, yes I mean the crane number doesn't match the frame. This gun is certainly worn out and I bought it cheap off gunbroker from Numrich to be a daily carry beater gun. It's becoming clear to me that it's really worn out altogether. I'm wondering if I just need to scrap it and buy something new for carry.

Is it worth trying to fit a new latch pin in or should I just give up on this one? This gun does not have any sentimental value is is in bad cosmetic (and obviously mechanical) condition.

I only gave $220 for it, it's not worth sending back to Colt for a few hundred dollar fix to me.

[A1A]

Closeups of your ejector star and latch pin would be interesting.

[grizzlyblake]

Here are the best I could get with my poor equipment. You can see that the edges of the latch pin are rounded and the inside of the extractor hole is beveled. This old gun may just be shot out. I made the pictures big for detail. Again, this was a cheap gun from GunBroker that was from a well known parts company, Numrich. It may well be a rebuilt parts bin gun since the crane and frame don't even match.

[grizzlyblake]

If anybody can tell anything from those pictures feel free to share. This is the first time I've dealt with the workings of a Colt. I can tell that my Diamondback and Detective Special are much "crisper" and don't have the worn and rounded edges.

[Brevity]

A few of suggestions.

Clean well underneath the extractor, and inside where the release sits.
Check the sideplate for any burrs where the release pin slides.
From your pictures it appears the extractor has been 'rounded out where the pin sits and the whole extractor thinned a bit too much.

[A1A]

I would agree that the ejector star is possibly the biggest offender. The latch pin recess appears "flared" and the end of the ejector rod either extends too far from additional threading or has been restaked such that the end is effectively raised. This can limit the latch's entry into the recess. As stated earlier, that is an issue because new ejectors are generally not available and need to be fitted along with other parts to result in correct head space, barrel/cylinder clearance and acceptable cylinder end play. The headspace (which is actually set by the cylinder collar) being excessive with the current parts could also contribute to the latch's inability to retain the crane. Although the fit certainly may not be correct, I would be tempted to swap in the crane assembly from your Detective Special just to see what difference it might make. If it improved the situation, it could somewhat exonerate the frame and latch and it would be a no cost experiment. Although you do not want to invest a lot in the Cobra, but since you own other Dframes and seem interested, I would also suggest that you purchase The Colt Double Action Revolvers, A Shop Manual, Vol.I, by Jerry Kuhnhausen, available from Brownells, Midway and some booksellers. It is a gunsmith level manual covering D, E and I frames.