I’ll preface this by saying that every time I spend time on this forum I learn something from someone smarter than myself in regards to firearms. Besides family, I shoot primarily with same 5 friends most of the time. Age ranges from 30ish to 55ish. All have been shooting for quite a long time. I was talking with one of them a couple weeks ago and it became apparent to me that he didn’t understand some basic 101 level stuff about ammunition. Eventually I said something along the lines of “You know that a 7.62 bullet is a .30 caliber bullet correct?” He responded with a blank stare for about a half a second. Then continued to talk the same silliness he was saying before. I didn’t want to offend the guy… But I stopped him again and said “Do you know that the same .30 caliber bullets, the actual projectiles, can be shot from many different rifles of different cartridges; like the 30-30, 308, 30-06, 300 Win Mag, and many more?” (Disclaimer: I understand that not every .30 caliber bullet can be loaded and shot in every .30 caliber rifle; especially with the real heavy 200gr+ bullets. I’m talking in generalities, mostly 150gr to 180gr stuff.) At this point he realized I was trying to explain something to him that he clearly did not understand. This lead to 10 minutes of very frustrating discussion. It felt like the “Who’s on First” thing from the Three Stooges. I tried explaining it in every way that I could think of. I couldn’t understand, what he wasn’t understanding about it. Maybe because he spent so many years believing something else was true, his mind just wouldn’t let him believe what I was telling him. I think it finally clicked with him when I explained “When I was a kid my dad and I would melt down lead. We would take that liquid melted lead and pour it into a mold. When we would open that mold up a couple identical bullets would fall out. Sometimes we would load those bullets into 30-30 brass and shoot it from my 30-30 rifle. Or sometimes we would load those bullets into 308 brass and shoot it from my dad’s 308 rifle. I saw the light go off in his head. It was like…. It was like… Remember when you were around 10 years old and you looked at your first nudie magazine and you realized “Oh, it’s actually located below the hair! I never knew!!!” Yeah, that was the level of epiphany this guy had. Over the next week or so I discussed the same topic with the guys I shoot with often. None of them knew that multiple rifle cartridges can shoot the same bullets. This sincerely blew my mind. I came to realize that sometimes what we consider common knowledge, isn’t so common after all. I texted my dad last night and thanked him again for all the time he spent teaching me this stuff while I was growing up. And it was a good reminder to teach my 2 boys the same.