I own a small frame Martini, and love it. Make certain the firing pin has been bushed, as the .310 used Berdan primers and the pin is a much larger diameter. If your going to hand load for it, use a primer with a hard cup (CCI.41) as the higher pressure loads, the cup tend to flow into the firing pin hole making it difficult to open the action. Mine is chambered for the .218 Mashburn Bee, the 22 hornet may not be a problem for this.
Bob