I keep my Gen4 21 packed with Liberty Civil Defense 78gr 1900fps https://libertyammo.com/product/civil-defense-45-acp/ I have in 40, I don't like the idea of their 9mm. I have some .380 in it. Not too keen on that either.
If you ever decide to chamber a round make sure you do it outside. The firing pin always dents the primer in that process. If the primer is defective/too soft it can go off. I know a cop who shot a hole from one end of his house to the other and out the end of the house.I've got an AR-15, but I've never even loaded it, much less fired it.