The more varied the firearm library is, the less you have to worry about what is available to shoot.
I have .22, .380, .38, .357, 9mm, .38Super, 10mm, and .45
But I also try to keep plenty of ammo.
"A well regulated Militia, being necessary to the security of a free State, the right of the people to keep and bear Arms, shall not be infringed."
Life Member NRA
Life Member NAHC