Repairing the Firing Pin on a Single Action Colt Revolver Copy

01
of 05

Assessing the Symptoms

Traditions Colt Single Action Army 45 Revolver - Firing Pin
The arrow indicates the firing pin, which didn't always stick through the frame very far. Photo © Russ Chastain

First things first - unload the gun and always follow basic gun safety rules.

My Italian-made copy of the Colt Single Action Army (SAA) had failed to fire on more than one occasion, and naturally this problem needed to be corrected.

The symptoms I had been experiencing were intermittent light primer strikes. Eyeballing the firing pin with the hammer all the way down (forward), I could see that it wasn't sticking through the frame very far. Clearly, that was my problem; the question was what to do about it.

The photo above shows the firing pin sticking through the frame just a little bit (the arrow is pointing at the tip of the firing pin). I messed with the firing pin, which was loose in the hammer, and proved to myself that it would stick farther through the frame if it stuck farther out of the hammer. In other words, the hole in the frame was not limiting how far the firing pin stuck through, which may sometimes be the case.

Sometimes, light firing pin strikes indicate a weak hammer spring, but that wasn't the problem this time.

More of This Article

  • 1: Assessing the Symptoms
  • 2: Examination Before Diving In
  • 3: Removing the Firing Pin
  • 4: Eyeballing the Cross Pin (Firing Pin Retaining Pin)
  • 5: My Solution and Conclusion

02
of 05

Examination Before Diving In

Traditions Colt Single Action Army 45 Revolver - Firing Pin and Hammer
This shows how the firing pin (left arrow) is installed in the hammer. The cross pin (middle arrow) holds it in place. Once you remove that pin, you can push the firing pin forward by inserting a punch into the hole at rear of hammer (right arrow). Photo © Russ Chastain

Examination and research revealed that a hole pierces the hammer from front to rear. The diameter of this hole is larger at the front, and the firing pin is installed by slipping it into that hole from the front. The firing pin - which was a loose fit in the hammer and wiggled back and forth - is retained by a cross pin, which engages a groove cut all the way around the firing pin.

The photo shows the firing pin (left arrow), the cross pin that retains it in the hammer (center arrow), and the smaller-diameter hole in the rear of the hammer (right arrow).

Before I took anything apart, I used a dial caliper to measure the distance from the rear of the hammer spur to the tip of the firing pin, with the firing pin pushed back into the hammer as it would be at the moment when it struck a primer. This provided a benchmark, so I would know where I'd started and could better assess my progress - or lack thereof - as I went. The measurement was 1.660".

More of This Article

  • 1: Assessing the Symptoms
  • 2: Examination Before Diving In
  • 3: Removing the Firing Pin
  • 4: Eyeballing the Cross Pin (Firing Pin Retaining Pin)
  • 5: My Solution and Conclusion

03
of 05

Removing the Firing Pin

Traditions Colt Single Action Army 45 Revolver - Firing Pin and Hammer Disassembled
After removing the firing pin from the hammer. The cross pin retains the firing pin by engaging that groove around the firing pin. Photo © Russ Chastain

I selected a pin punch that was just a touch smaller than the cross pin, and drifted the pin out of the hammer using a small brass hammer on the pin punch. I supported the hammer while doing so - if I hadn't, I would have put stress on the hammer and frame. Never drift or drive parts without properly supporting the parts.

After I drifted the cross pin out, the firing pin came out. If I couldn't have pulled it out using needle-nose pliers (which is what I did), I could have pushed it out using a punch or other item in the firing pin hole in the rear of the hammer - that's why the hole goes all the way through the hammer.

The photo shows the firing pin and cross pin lying next to the hammer. You can see some damage to the center of the cross pin; both of these parts are soft, and the cross pin and firing pin were both peened. Better hardening at the factory may have prevented my problems altogether.

More of This Article

  • 1: Assessing the Symptoms
  • 2: Examination Before Diving In
  • 3: Removing the Firing Pin
  • 4: Eyeballing the Cross Pin (Firing Pin Retaining Pin)
  • 5: My Solution and Conclusion

04
of 05

Eyeballing the Cross Pin (Firing Pin Retaining Pin)

Traditions Colt Single Action Army 45 Revolver - Firing Pin Retaining Pin
Here you can see how the retaining pin has been peened and deformed against the firing pin. Photo © Russ Chastain

This close-up of the cross pin shows how it's been deformed by peening action against the firing pin. I'm sure this contributed to my problem by allowing the firing pin to move back into the hammer too far - but was that the entire problem? I wasn't so sure.

I re-installed the firing pin, rotating it 180 degrees and turning the cross pin also, so that both pins would be riding against one another on un-worn surfaces. When I checked the resulting length against my benchmark measurement, however, I could tell that any improvement (I was looking for an increase in overall length) was minimal at best - and even if I had been able to cure it in that fashion, the same wear that had caused the problem would naturally have allowed it to recur.

I needed a better solution.

I moved on to other projects for a couple of days, while this simmered in the back of my mind. I thought about it and determined that the most obvious solution was to drill the cross pin hole to a larger size that would best match the groove in the firing pin, make a new cross pin to fit it, and try that.

On the second day, I decided that the best approach would be to do just that - but I wasn't ready to begin. It needed to stew a little more - and another, perhaps less obvious, solution had occurred to me, which required more thought.

I thought about the work involved in drilling out the cross pin hole in the hammer, turning a new pin on the lathe, final fitting of the pin, hardening the pin, and then hoping that when I put everything back together, the increased "stick-out" of the firing pin would be enough to matter.

This last part was a bit of a gamble, because the best possible result would be an improvement of only half the difference in diameters between the old and new cross pins.

In the end, I settled on a much simpler approach. I purchased a small allen-head 6-32 set screw at the local hardware store and set to work. I drilled out the smaller portion of the firing pin hole - the one that goes through the rear of the hammer - and tapped it with 6-32 threads. Then I de-burred the rear end of that hole, where my tap had created some raw edges, and put everything back together.

More of This Article

  • 1: Assessing the Symptoms
  • 2: Examination Before Diving In
  • 3: Removing the Firing Pin
  • 4: Eyeballing the Cross Pin (Firing Pin Retaining Pin)
  • 5: My Solution and Conclusion

05
of 05

My Solution and Conclusion

Traditions Colt Single Action Army 45 Revolver - Threaded Hole in Hammer
The hole in the rear of the hammer is now threaded, and a set screw inside of there bears against the back side of the firing pin. Photo © Russ Chastain

After I had pinned the firing pin into the hammer, I screwed the set screw into the hammer from the rear and tightened it against the rear end of the firing pin to hold the firing pin forward. Voila! I had saved a bunch of time and created what I believe to be a more positive solution to the problem.

When I measured the spur-to-firing-pin-tip distance again, I found it to be 1.675" - a marked improvement over the original 1.660" dimension. The photo above shows the threaded hole from behind - the set screw is way in there, out of sight.

Use caution if you attempt a similar repair - some hammers are hardened much more than others, and would pose more problems to drilling and tapping.

I removed the hammer from the gun to do the work. I drilled the hole out from the front of the hammer, because that allowed the bit to start nice and straight rather than trying to start drilling from the back side - which would have placed the bit non-perpendicular to the hammer and thus more likely to break.

While cutting the threads, I used plenty of tapping lubricant and only advanced a very small amount at a time. I had no desire to break a tap inside the hammer! Doing things like that will ruin a tap, a hammer, and your day in one fell swoop. Turn the tap in just a bit and then turn it backwards far enough to cut the chip that the forward motion raised, and repeat. Many, many times.

If your single action revolver is failing to fire sometimes, your problem may or may not be the same as mine - but this should give you some ideas for those guns whose firing pins are too short and just aren't reaching far enough to pop every primer.

- Russ Chastain

More of This Article

  • 1: Assessing the Symptoms
  • 2: Examination Before Diving In
  • 3: Removing the Firing Pin
  • 4: Eyeballing the Cross Pin (Firing Pin Retaining Pin)
  • 5: My Solution and Conclusion