has anybody ever heard of a .218 hill [s] caliber? the caliber is marked on the bbl. of a cadet martini sporter that has come into our shop in upstate n.y. j.r.boon                                                 thanks for looking guys, it seems that it is likely the product of a local gunsmith who used to teach at r.i.t. in the school for americam craftsmen program. it looks to be a necked down .25-20 or  who knows? chamber cast might tell.j.b.