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Author Topic: Base Pin Retention Issue On SAA  (Read 1082 times)

Offline scooby

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Base Pin Retention Issue On SAA
« on: January 17, 2014, 09:59:19 AM »
Noticed this issue right after I got the 3RD Gen Colt SAA, but if I happened to get the spring setting just right in the cross hole of the frame, it worked just fine and the base pin would stay locked in place. However, on a few occasions during shooting sessions, the spring would move under recoil, make it's way past what remained of the recess shoulder in the cross hole, and then the retainer assembly would no longer keep the base pin in place due to no longer having any spring pressure. So I decided that a small repair was in order.

Hear are a few pics to give a visual of the issue and further explain the fix.

This shows the cross hole through the frame that the base pin retainer assembly sets in. Cross holes are supposed to have two seperate diameter sizes in order for the retainer spring to have a shoulder to rest on in order to provide tension. In this case, the larger diameter portion was drilled too deep from the factory and half of the shoulder was obliterated. What this caused is an oversized hole that would allow the retainer spring to eventually work it's way through loosing the needed tension, and in turn, the retainer assembly would no longer keep the base pin secure. You can see where the shoulder is gone from the 10 oclock position clear around to the 5 oclock postion.What remains of the shoulder is rather thin.


So for a simple fix, I decided to make a shim washer from some sheet brass stock I had on hand. I first drilled the right sized hole in the brass and then placed the base pin screw through the hole and scribed around the head of the screw to give me the approximate outside diameter needed for the shim.Here sets the drilled and scribed piece of brass after I cut free from the larger stock section.


I found this old antique jewelers vise to be very handy when working on small items. I can now rough file the shim to a round shape by following my scrim line.


And the file work is complete.


Now I just need to clean it up some on the stone and with some 600 grit paper.


I also wanted a better spring for the retainer assembly, so I cut some from spring stock of the right diameter. The new section sets closest to the caliper and the old spring is below it. To the lower left sets the retainer screw and nut. The tension spring simply slides over the shaft of the retainer screw.


And here you can see the fitted washer in place in the cross hole. I now have a full diameter lip that the spring can make complete contact with and it can no longer work it's way beyond the shim into the base pin hole of the frame. I guess I will find out in the future how well it works.

Offline Kaboom

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Re: Base Pin Retention Issue On SAA
« Reply #1 on: January 17, 2014, 01:11:11 PM »
I would think that would work just fine. Really a good solution, if you ask me (which you didn't, but I told ja enny ways).  Right on!   )k*
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Offline Captainkirk

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Re: Base Pin Retention Issue On SAA
« Reply #2 on: January 17, 2014, 06:18:26 PM »
I love it.....all hand tools, and most appear antique. Nice work, and thanks for the Most Excellent pictures to tie it all together! If you just explained it I probably wouldn't have a clear understanding of what you did. Thanks, Scooby!
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