I have a J frame with the lock, it has seen hundreds of rounds without issue.
So, I don't like the lock, but it has been no problem either.
The new Hornady Critical Defense 110gr load might be a decent choice in std pressure, but I personally prefer to error toward penetration vs a light expanding bullet, so in common ammo I'd pick a good 158gr SWC load or best yet, the Buffalo Bore std pressure wadcutter.
They make a decent 125gr jhp load too.
The West is the Best.