A "True" 36 gauge has a bore diameter of .506". In the early days some makers of .410's listed them as either 12mm or 36 gauge, neither of which accurately describes their bore size. .444 Marlin brass can be made into short .410 cases but a .30-30 is too small even for that use, much less a true 36 gauge gun.


Miller/TN
I Didn't Say Everything I Said, Yogi Berra