Since it's made by SIG, who ALSO makes 9 mil pistols, COULD I expect problems using it in my Ruger American 9mm? — 3 Answers

Do plenty of research, the "9mm" is the same as 9x19, 9mm Luger, 9mm Para (parabellum) there is one 9mm you cannot use and that's the 9x18 or 9 Make or the 9mm Makarov. You sound new to firearms and that's OK, but this is a right/sport/hobby, where you're handling something that has the possibility to be deadly, so we emphasize SAFETY. And your question is valid, although a quick Goog will give you a sufficient answer and info, which you've probably done since it's 2022 now, some of the most important thing with guns is SAFETY, proper use, training, and storage. I had a retired Sheriff ,swat, all the leo stuff say in regards to accidental discharge, "There's 2 types of gun owners ones who've had an accidental discharge, and those who will." So use ya head.

9MM AMMO WILL SHOOT IN ANY AND ALL 9MM GUNS PLEASE GET HELP NOW BEFORE YOU SHOOT YOURSELF PLEASE