My grandson, age 11, was given a sporterized 7.7 Jap, slugged diameter .316, by his other GF. I'm the caster/reloader. They are a hunting family and live in the Michigan Upper Peninsula. With .30-06 cases converted to 7.7, can these cartridges mistakenly be fired in a 30-06 rifle? What's the potential results? I'm buying a mould and all of the other tools to put 50 rds together and then the stuff is going to be shelved. I'm 76, not going to be around forever, and don't think this equipment will be used (perhaps) until the boy is on his own. I wish the rifle had been converted to a common caliber appropriate for a young boy. Your thoughts, please. Thank you.