I have quite a few Tyler adapters - I have had success using K-frame adapters on my N frames and J-frame on my K's. Another bit of info FWIW...last time I ordered from Tyler they cashed the check, never sent the adapter, and never responded to my VMs or emails. I obviously won't buy from them again. I wanted one for a New Service; I found a vintage Pachmayr on eBay and went with that.