Call Ruger parts, they'll send small parts like that for free.
And yes, that's the remedy I figured out years ago to replace the lock. Here's some detail.
Internal locks:
To replace an internal lock (which was discontinued in 2012), all the internal parts and the hammer spring can be used except for the lock of course. But a standard style spring perch is needed to mount the hammer spring. The Bearcat perch is the only one long enough, discussed below and has added advantages. But a standard style spring perch, is needed to mount the hammer spring. The Bearcat perch is the only one long enough, discussed below and has added advantages.
When the locks first made their appearance in 2005 on the .357 Anniversary model Flat Top Blackhawk and New Vaquero, I started making and selling this titanium lock bypass seat, but no longer make them because the Bearcat seats are free:
An even simpler alternative is just a flat piece of steel with an oblong hole for the spring strut that will work; the spring tension will keep it in place:
Back in 2007 I had my Bearcat apart and noticed that its spring seat is the longest seat made for any of the Ruger single actions, go figure!! It just bridges the gap in the grip frames made for the internal lock and I posted its use as a replacement for the lock, on the other Ruger forum at the time.
It's an inexpensive Ruger part, that’s all I use now, and quit making/selling my own.
The beauty of the Bearcat spring seat is that it disassembles the same way as the lock with the disassembly pin hole right below the spring so the spring never has to be dismounted from its strut, which can be a gruesome task for many.
To swap the Bearcat spring seat for the lock is the easiest swap there is. You don’t even need to remove the grip frame, just the grips! After cocking the hammer, a disassembly pin like a nail is inserted into the spring strut hole thru the groove in the top edge of the lock. Now uncock the hammer so the spring and strut have play. This allows the lock to be wedged up and out of the grip frame, and off of the strut. Because the temporary pin used to hold the spring compressed, fits in the groove on the top of the lock, the spring is still captured on the strut.
Therefore the strut and spring assembly doesn’t need removal from the hammer slot. More importantly, nor does the spring need to be dismounted from the strut like Ruger SAs w/o the lock, where the disassembly pin is inserted below the spring seat which is captured on the strut along with the spring.
With the regular spring seats captured on the strut with the spring, the grip frame must be removed or at least loosened to change spring weights. It's also more difficult to mount a spring and a seat on the strut, rather than just a spring.
Now once the lock is out of the grip frame, the Bearcat seat slips on the bottom end of the strut below the spring retaining pin. The Bearcat seat also has a round hole in it for the end of the strut, so once on the strut, it can be pivoted 90 degrees, strut and seat moved into position over the gap in the grip frame where the lock was, then pivoted 90 degrees onto the two shelves of the gap.
Now hold in place, cock the hammer, remove the spring retaining pin, and drop the hammer. Voila, all done. The seat doesn't overhang the gap where the lock was very much on either side but once the spring tension is applied, the seat is held tightly in place.
I've been using these for years on dozens of guns and never had one slip yet. Some have reported issues retaining the Bearcat seat on the round corners of the grip frame gap: you can file a small shelf on either side of the gap in the round corners to insure the seat stays put.
The Bearcat perch does not have a hole in the center of it, it's offset to one side. If you have a Ruger with the new grip spacer around the grip screw, and it doesn't fit back in the gun when installing the grips, the bearcat seat must be mounted in the other direction for the spacer to clear the hammer spring.
There you have it, the history of the Bearcat seat replacement for the Ruger lock which was discontinued in 2012.
I even use the Bearcat spring seat on other Ruger's w/o the lock so I can quickly try different spring weights which I've pre-mounted on spare struts because of the easy changeability with the Bearcat seat!
This is especially helpful on the single sixes because they have the same tension springs as the larger Blackhawks, but their shorter hammer has less leverage than the larger frames. .22s do need stiffer springs to detonate rim fire cartridges, especially the 22 Mags, but the Ruger springs are overkill IMO.
Therefore I experiment with spring tensions until I get a compromise of easier hammer cocking for my grand kids, but with reliable ignition.
NOTE: the hammer springs that come with the lock in the New Vaqueros and Flat Top Blackhawks only, are only 25 coils since they were designed by Ruger to be softer/lighter for Cowboy Action shooters. I always retain them when removing locks and also use them as replacements in all other Ruger SAs. Especially Ruger Single Sixes with its shorter hammer resulting in less leverage and harder cocking.
Lock shown here: http://www.gunblast.com/images/Hamm_Ruger-SA-GripFrames/DSC00231.jpg
Bearcat spring seat shown here: http://www.gunblast.com/images/Hamm_Ruger-SA-GripFrames/Dsc00106.jpg
From Brownells #780-000-948AK, $2.95, here:
http://www.brownells.com/handgun-parts/frame-parts/mainspring-parts/mainsprings/mainspring-seat-sku780000948-11856-28534.aspx?sku=780000948
Or order direct from Ruger part # PR5, they’ll send it free.
