Always remember the basics...

Good on you for being safety minded, and hoping your kids will remember that lesson forever!

I think I'd be letting the person you got that from know...

Glad everything turned out well and nobody got hurt.

Some years ago,a friend asked me to sort out a drum and nipple on a nice original American Rifle.The Drum had some how been bent backwards but was tight in the breach.I lit my Propane Torch ready to warm it up when it came to me that I had no idea if there was anything down the Barrel.I put a rod down and sure enough it stopped some four inches from the breach.I soaked the Breach Plug in Hot oil overnight and managed to get the plug out the next day.The gun was still loaded,the Ball had a cloth patch that had almost disintegrated and the powder was a rust colour.I put a match to it on the bench and it flared up.I had put the barrel in my vice and it was pointed towards my garage doors.That Rifle must have been loaded in America many years ago and exported to England as an antique fully loaded.

Well as has been pointed put many times here on THR, the piece was "charged" not loaded.

it had batteries?

It doesn't fit the legislative definition of "loaded" (no cap) but that's still the language people use. If it's been pointed out "many times" that it's something else with no effect that's because people don't actually call it that.