Have read a few posts here that suggest that the standard .22 Hornet Lee collet die will work OK on the K Hornet . Tried it today and despite adjustments could not make it work without crushing the case .
BTW the Lee Hornet bullet seater is bloody hopeless with some projectiles .

I haven't tried the Lee collet die but I do have a set of RCBS FL K hornet dies and a Redding neck die. I especially like the Redding Neck die and I find my accuracy has improved since I got it. The RCBS FL dies were sizing down the cases slightly.

I have used the Lee collet die for the regular Hornet with great success. If you send the die back to Lee with a few cases, they will rework it to work with your K Hornet.

Ordered a Redding 3 die set today . Too much hassle to send my Lee die back to the manufacturer from Oz . Did like the collet die though .

Nope, I've tried it and the Lee Collet die will almost but not quite work with the K-case. In theory, it should be a fairly simple amatuer machinist process to drill out the shoulder area of the collet with the properly-sized bit to allow the K-hornet to enter far enough, but having a drill bit hard enough to drill the hardened steel is another matter. I may give it a try when I have some time to kill.