SAA Not Locking Up

Started by Shotgun Franklin, July 23, 2011, 03:49:37 PM

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Shotgun Franklin

About once a shoot, 100 rounds or so, my SAA over rotates. The firing pin will hit the edge of the primer. I haven't been able to duplicate this by dry firing or just cycling the action. I intend on field stripping the gun tonight. Any suggestions as what I might be looking for? My guess is that the bolt isn't popping into place. Maybe some hidden crud? It does have a fairly new bolt spring. The action is tuned and I've used this gun for 5 years at least. It's a Taylor & Co/Uberti.
Yes, I do have more facial hair now.

St. George

It's likely that some detritus has managed its way into a kep position every so often.

A 'thorough' cleaning should fix this problem.

Hope so.

Vaya,

Scouts Out!
"It Wasn't Cowboys and Ponies - It Was Horses and Men.
It Wasn't Schoolboys and Ladies - It Was Cowtowns and Sin..."

maldito gringo

As a first step, a thorough cleaning is a must. Pay particular attention to the locking slots on the cylinder. Get in there with a Q tip
and some simple green or denatured alcohol. Try fit the bolt by hand into each slot in turn. It is possible that over time a burr has formed on the edge of one slot, or the head of the bolt is slightly mushroomed. Check the bolt window for the same problems.

Fox Creek Kid

You've left out critical info:

1. Aftermarket piano wire bolt spring?

2.  Cocking two handed fast & furious?

John Taylor

sounds like the other have it covered good. Might also look at the side of the cylinder bolt where it cams on the hammer. May not be releasing clean, look for smoothness. Make sure all the parts are moving freely. A drop of light oil in the works may help a lot. Do not use WD40 or PB blaster for lube.
John Taylor, gunsmith

Shotgun Franklin

The gunsmith says that this gun was set up with a very tight fit of the bolt into the cylinder cuts. With wear the bolt head is skipping out of the cut and letting the cylinder move past the cut. I now need to decide which way to go, maybe narrow the bolt a bit or re-cut the cylinder?
Any opinions?
Yes, I do have more facial hair now.

maldito gringo

Unless the locking slots have become damaged there is no reason to recut them. The bolt must be hand fit to the locking slots.
I assure you that this is something you can do yourself. Rather than outline the process here, I STRONGLY recommend that you invest a modest sum in Jerry Kuhnhausen's excellent manual on the Colt SAA, and read it cover to cover. The section on bolt fitting will answer all your questions regarding this problem.

Shotgun Franklin

I'll have to hunt a copy up.
Yes, I do have more facial hair now.

Driftwood Johnson

Howdy

Before you start messing with the bolt, try one other thing.

Make sure the gun is unloaded. Try cocking the hammer briskly, but before completing the stroke, hesitate for a moment. Don't quite complete the stroke. After hesitating, deliberately complete the hammer stroke. Does it do it with this test? If so you may have a weak hand spring. You may be hesitating while cocking the hammer and not realize it. If you hesitate when cocking a gun with a handspring that is too light, sometimes it will over rotate.

Another test. Put the hammer at half cock and spin the cylinder. Give it a good whirl. Does it sing loud as the hand snaps over the cylinder ratchet teeth? Does the cylinder slow down pretty quick? Or does it sing quietly and does the cylinder want to spin forever?

You mentioned the action has been tuned. A lot of smiths are not aware of the fact that the hand spring needs to exert a little bit of 'braking force' on the cylinder. Instead they weaken the hand spring so that the cylinder will spin very freely. This is a misguided effort and smiths should not do it.

You also mention this happens only when you are shooting. This is also consistent with a weak hammer spring. After a few rounds have been fired, the remaining bullets in the chambers have essentially unbalanced the cylinder. With all chambers loaded, the cylinder is balanced just like a properly balanced tire. With a few empty chambers, the cylinder becomes far more dynamically unbalanced than a tire that is unbalanced.

One third test. Load two dummy rounds into the cylinder in two chambers right next to each other. Be sure they are dummy rounds with no powder or primers, but use real, full weight bullets. Try the hesitation thing again.

What happens when you hesitate while cocking the hammer with a weak hand spring is the cylinder has developed enough momentum to keep on spinning, but by stopping the stroke before full cock, the bolt has not popped up yet. If this is done with proper hand spring tension, the hand will press against the cylinder ratchet teeth and prevent the cylinder from rotating too far. With insufficient hand spring tension, the cylinder teeth push the hand out of the way and the cylinder over rotates past proper alignment. When the hammer stroke is completed, the bolt pops up, but the cylinder has already rotated too far and the bolt cannot slide properly into the stop notch on the cylinder. This condition has nothing to do with proper fit of the bolt in the stop notches, it is because the hand spring is too weak.

I have a Colt that originally had a weak hand spring and I could get it to over rotate every time if I hesitated when cocking the hammer. I just remembered to fully cock the hammer every time. Finally I replaced the hand spring with a new one. The gun never over rotates any more. I am playing with it right now, cocking the hammer every which way, including hesitating. Every time I complete the stroke, the gun goes to battery properly.

If you buy Kunhausen's book, which I highly recommend, he outlines this problem in paragraph G on page 226. Please check for a weak handspring before doing anything to alter the fit of the bolt. Hands are cheap. So are handsprings. Bolts are expensive and you do not want to be altering it if it is not the problem.

Kuhnhausen also shows on page 214 how to properly tune a handspring to prevent this problem. Most handsprings are not properly shaped when the gun leaves the factory. You can buy Kuhnhausen's book here:

http://www.gunbooks.com/colt_sa.html

Yes, it is expensive, but it is well worth it. It is the best book there is for working on Colts or clones. You can also order it through Brownells, Midway, or even Amazon.

Hope this helps.
That's bad business! How long do you think I'd stay in operation if it cost me money every time I pulled a job? If he'd pay me that much to stop robbing him, I'd stop robbing him.

Ya probably inherited every penny ya got!

Shotgun Franklin

New bolt spring, Colt made, and new hammer spring. Still not working.
BTW, I shoot Gunfighter.
Yes, I do have more facial hair now.

Driftwood Johnson

QuoteNew bolt spring, Colt made, and new hammer spring. Still not working.
BTW, I shoot Gunfighter.

Perhaps you should read my post again. The condition I am talking about has nothing to do with the bolt spring or the hammer spring. It has to do with a weak hand spring. It has nothing to do with shooting duelist or gunfighter, it happens when the hammer stroke is interrupted. Most likely to happen when cocking the gun with one hand. Not likely to happen when cocking the gun with two hands.

Try my three simple tests to see if you have a weak hand spring that could perhaps be causing your problem.
That's bad business! How long do you think I'd stay in operation if it cost me money every time I pulled a job? If he'd pay me that much to stop robbing him, I'd stop robbing him.

Ya probably inherited every penny ya got!

Shotgun Franklin

I was trying to answer several posts at once. I will try your suggestions. And that was my mistake, the hand spring has been replaced with no improvement.
Yes, I do have more facial hair now.

Mr Bear

Try doing a Bob Munden on the front ledge of the bolt, take some material off so that bolt rises up all the way into the cylinder notch and locks 'er up like a bank vault.  Can only help, and won't hurt anything.  All the best,
                                                                                                                                    Mr Bear

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