Be sure to check for the price and availability ofadditional factorymagazinesregarding the manufacturer and model you are looking to purchase. Also look at the prices and availabilityof a holster if itcould be a carry gun. Even if it is only used asa house gun, a holster can come in handy (shotgun as main defense gun with a hg as a backup).

Currently, thereis not much if any ammoprice differencebetween the 40S&W and the 45ACP. Make sure the 45 is an ACP and not a GAP.

Have you shot either caliber? If not, I suggest you shoot both calibers from the same model (XD, same brand and model1911, etc.). IMO, the 40S&W has more of a snap and the 45ACP has more of a push. If you live in an area where hollow points or expanding bulletsare not allowed, I would definitelygo with the 45ACP as even the ball ammo has decent stopping ability. The 40S&W and 45ACP each have their own strong points.