I'm with Mr Schoyen on this; it's a beautiful little rifle and should be relined to .22 Hornet (or K-Hornet or .25-20SS) and the caliber marking removed and replaced. This would involve the least "messing with" and relining is a solution even the Old Ones would approve. I've used Mark Beinke in Klamath Falls OR for relines. If he's still working, he's a good guy and does beautiful work.(Say his name Ben-kah, the German way--it helps overcome the crankiness occasioned by 1) being a gunsmith who naturally gets 1001 stupid questions a day, and 2) his bad back caused by 1.).
Not a Hauck action, I think, although I can see why Mr. Ken is reminded of one. Looks German to me; once my visiting Marine wakes up and I can get to my books, I'll look it up.
What a nice rifle and great project! Thanks for sharing; guns like this MAKE my day! I know this forum will help make my NEW YEAR; hope you all have a great one!
Mike Armstrong