Having owned and shot many swiss k-31 one of my favorite calibers is the Swiss 7.5X55. I talked to my gunsmith/rifle maker and he says he can get a reamer for the 7.5 Swiss.The plan is to build a single shot target rifle useing a savage action and a 26" heavy Lilja barrel.I'm new here and want to say this is a great forum.I have 3 Savage rifles 2-223's and my pride and joy a older Chieftan in 7X57.