Remember when the New Vaquero came out? Internal lock. Remember when the .22 MKIII came out? Internal lock. Then there is the P345. Internal lock. I predict that in the not too distant future more, if not all, Ruger handgun models will have this addition. When they first appeared in a Ruger model the addition of the internal lock was kept somewhat quiet. You actually had to "research" to find out about it. It seems like it was a feature that Ruger didn't want to advertise and understandibly so. I think most experienced gun enthusiasts prefer to not have the additional mechanics. Plus, they are sometimes ugly depending on the placement. An example of the unpopular feature being added and then dropped is the Remington 700. Obviously, some people don't mind them, and some have bought into the marketing of additional "safety improvements" but I don't think many actually use them. If you count the padlock, the P345 now has at least 5 safeties.
Anyway, I think all Rugers will eventually have these added.
Anyway, I think all Rugers will eventually have these added.