I will go with the one that share the same caliber with your "primary weapon".
You will be benefit from doing so - lower ammo cost & greater commonality between your primary & back up piece.
I'd go with a Glock 26 if you have a 9mm, it is hard for me to shoot since the grip is way small for my hand, but it is a reliable hole-maker!
S&W will be my choice if my carrying piece is chambered in 40/45/38/357/10mm...etc.
You will be benefit from doing so - lower ammo cost & greater commonality between your primary & back up piece.
I'd go with a Glock 26 if you have a 9mm, it is hard for me to shoot since the grip is way small for my hand, but it is a reliable hole-maker!
S&W will be my choice if my carrying piece is chambered in 40/45/38/357/10mm...etc.