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
Former President of the ECPT (Eifel Combat Pistol Team)