Colt Gold Cup Nat Match problem

[jim-analog]

Greetings,

I'm having a very strange issue with my 1970s gold cup MK4/Series 70. I am NOT the original owner of the pistol and not aware of much of its history. It had been owned at some point by a serious competitor, who may have had some "custom work/fine tuning" done (or not)...........see below:

To try and make this short, it was working ok, but recently started to have some FTEx issues. I did a complete detail strip and think I found the cause of that, but ended up with a completely different problem now. It seems I'm getting NO contact between the hammer hooks and the sear engagement surface. Can't cock the hammer back either with the slide or manually and have it hold; obviously the gun is now 100% non functional.

SO, a question that may help me out...............specific to the Gold Cup models, there is an additional spring that sits in the sear and an additional level it works against. IIRC, this was to minimize/eliminate "sear bounce". Now, these two parts do not exist in my pistol. My question is..........what would be the symptom of an otherwise perfectly functional GCNM IF these two parts were removed? FYI, they can be seen in a really good drawing on page 29 of Kuhnhausen Vol 1.

Sorry to be a bit vague, but I didn't want to write a hard to follow 10 page essay. An answer to this question would give me a good start on an idea I have or may lead to another question or three. Many thanks!

Regards, Jim

[gold cup abuser]

Quick check......

That spring is not really needed for the weapon to fire. Its just to make the trigger pull feel better.

With the firearm cleared and detail stripped at the frame level, lets try the following:

1. Using the sear retaining pin and the hammer pin, mount the parts OUTSIDE of the frame. This should check that the hammer and sear are making contact and no parts are worn or broken.

2. With the mainspring housing removed, take out the pin that holds the spring in place. Do this in a plastic bag, and put some pressure on the cup that the hammer rod sits in. Lets make sure that the spring in there is not binding.

3. The trigger is adjustable, so check the adjustment screw to make sure that it is not blocking the hammer from falling. After reassembly, with that screw removed, see if the hammer falls.

4. Last thing to check is the sear spring. Confirm it is in place properly and it is not broken or worn out.

Let me know how this works for you.

[Grey Bearded One]

Quick check......

That spring is not really needed for the weapon to fire. Its just to make the trigger pull feel better.

I thought that it was there to keep the sear from disengaging when the slide slammed home.

[gold cup abuser]

I thought that it was there to keep the sear from disengaging when the slide slammed home.

It is supposed to keep the hammer from going into half cock mode by putting additional tension on the disconnector and sear. All it really does is piss you off when you lose the spring when doing a detail strip, and a bit of smooth to the trigger :|

This is a result of the steel trigger used in some of the early Gold Cup models causing hammer bounce. Aluminum trigger should solve that one, but then again so would testing the disconnector and hammer half cock notch for function. Which is what you are supposed to do before you shoot the 1911

[jim-analog]

Greetings,

Thanks for the suggestions GCA! OK:

I didn't think the spring and lever were required, but wanted to be sure before proceeding.

1. Great idea! Wish I had a jig to do this test, but I did what you suggested. It's a bit hard to maintain alignment, but both the full cock notch and the half cock notch do indeed catch. The full cock is VERY slight; I think someone went a bit too far with a stone, but the pistol WAS working in this regard Friday.

2. Main spring/housing are just fine; no binding or kinks.

3. Didn't try that yet, but I had not messed with the set screw and it did work with it adjusted where it is. I'll come back to this if nothing else is found, but problem isn't (at first) hammer NOT falling, but hammer NOT catching. I can't even get it to catch (fully assembled) at the half cock notch.

4. Well, this could be something (or not). It's definitely in place correctly, not sure about the adjustments though. The right leaf for the grip safety was set REALLY light, so that the grip safety would jiggle around. I very slightly adjusted that leaf for a bit more pressure on the G/S. The middle sear leaf was what I was suspecting...............again, I *VERY* slightly increased the tension against the sear, but this didn't seem to do anything. I didn't do anything with the left trigger leaf. I need to look up the adjustment procedure for this spring and see if there are some measurements I can take.

I'll keep trying and report back any findings. Thanks much!

Regards, Jim

Quick check......

That spring is not really needed for the weapon to fire. Its just to make the trigger pull feel better.

With the firearm cleared and detail stripped at the frame level, lets try the following:

1. Using the sear retaining pin and the hammer pin, mount the parts OUTSIDE of the frame. This should check that the hammer and sear are making contact and no parts are worn or broken.

2. With the mainspring housing removed, take out the pin that holds the spring in place. Do this in a plastic bag, and put some pressure on the cup that the hammer rod sits in. Lets make sure that the spring in there is not binding.

3. The trigger is adjustable, so check the adjustment screw to make sure that it is not blocking the hammer from falling. After reassembly, with that screw removed, see if the hammer falls.

4. Last thing to check is the sear spring. Confirm it is in place properly and it is not broken or worn out.

Let me know how this works for you.

[gold cup abuser]

From further review it would appear that the disconector is failing. I thought the issue was hammer not falling.

The sear spring places tension on the grip safety, the hammer and the disconector. So we are down to possibly 2 fail areas.

With the weapon fully assembled, and checked and rechecked for no magazine and clear chamber.....

1. With the hammer down, depress and hold the trigger to the rear. Now with your free hand rack the slide. DO not let the trigger go.

If the hammer falls then the disconector is failing. But as you are describing the sear spring, it may be contributing to this.

Give this a go and see what happens.

[Lycanthrope]

He said he didn't do anything to the left leaf. The left leaf is the sear leaf.

I'd start THERE.


LycanorI'mtotallymissingsomethingthrope

[bdriller]

If you can't figure it out ride over to Sarco, Chuck Lutz works there he will be able to tell you what is wrong. Hope this helps

[jim-analog]

Greetings,

You nailed it Lycanthrope! The left leaf wasn't engaging completely with the sear. Can't believe I had it in and out over a dozen times and didn't see this earlier. A minuscule tweak to the end of the leaf and all is well.

I still want to find an adjustment/measurement procedure to go over this 3 leaf spring and make sure it's ok and correctly adjusted. I have no idea how long it's been in the pistol, how many rounds, etc..

My plan is to order a spring set (recoil, fire pin and main) and while awaiting them figure out the proper method to use to "test" the sear spring. I think those 3 springs were probably set up for light weight target loads and all I shoot through this gun is 230g ball.

Thanks VERY much to all the respondents! It was a big help and saved a lot of frustration over the weekend. You guys are great!

Regards, Jim

He said he didn't do anything to the left leaf. The left leaf is the sear leaf.

I'd start THERE.


LycanorI'mtotallymissingsomethingthrope

[Lycanthrope]

There's no set way to adjust them. I set the right leg/grip safety pressure to my personal taste. I set the center leaf/disconnector/trigger return to 8oz on my game guns and 12oz on everything else.

The sear leaf/left leg is the tricky one and will depend on your hammer/sear engagement. A well done set will hold with very little pressure, while others needs considerably more to be safe.

To test, you want to lock the slide back and release it with the slide stop/release lever. This will allow the slide to release into battery at a faster speed than if it was stripping a live round (don't use a snap cap for this test). It will also bounce the sear and the trigger will fall to half-cock if there is not enough sear spring pressure or the trigger group is worn. As an added measure I also snap the gun forward when I do this to increase slide speed and maximize the possibility of sear bounce. If it holds for 3 times, you're usually ready to go. Don't overdo it on this test, however, because this is had on the trigger group.

If you have any questions, feel free to ask.

Lycangoodluckthrope