Hi Mike, Price would be very hard to quess with no pic's or make of the gun and its condition, Dicksons book "European sporting cartridges" pg 43 lists 11.15 x 55R MB Target.AKA 11.15x55R Austrian Target. This is about as close as I come to what you describe, as far as comercial rounds, I dought you would find any. My 10.25 x 60R Buchsenflinte (cape gun) & my 12.7 x 65R double rifle both required me to form my own cases from something else. Hope this helps you out.

m4220