Robb Barnes said:
No company sells those adapters so you have to make them yourself or the easy way is to buy one of David Clements hybrid triggers for old model guns but uses new model trigger return springs. The main struts should be the same as long as you are not using an internal locking main strut grip frame.
Even if you have a NM grip frame with a lock, it and its spring w/strut can be used with or w/o lock.
If you don't want the lock, just substitute the Bearcat spring retainer. Ruger will send you one for free, part # PR5, 336-949-5200.
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.
The spring does not 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.
Another 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.