Not really for k frame revolvers - Safariland 568 Custom Fit for Revolvers Holster - STX Plain Black, Left Hand 568-09-412

As the model number indicates, this holster fit the L frame guns better than the K frames. I turned down, or in, the adjustment screws until I hit the stops. My Model 10 was still loose enough to fall out easily, if the holster ever was inverted.
I ended up putting in a few small pieces of the rubberized grip tape, near where the cylinder should have touched the inside of the holster. This, and being tightened down all of the way now keeps the K frame secure.