The 5 rules of a gun fight
1) Gun beats no gun
2) A hit beats a miss
3) Fast beats slow
4) Big holes beat small holes
5) Two holes beat one hole
Understanding these simple facts AND THEIR MEANINGS, can greatly assist in the selection of a sidearm.
Ergonomics
Felt recoil - a full house magnum shot from a titanium 2” snubie is going to cause pain.
Gun mass / caliber Relationship.
Cost should be last. All you cheapskates who buy cheap shit may regret it when the gun doesn’t go boom when you’re being chased by five democrats with knives and machetes.