(sounds downstairs)
Me: Oh! Let me get my handgun. Let's see, the code is 8-1-2-4-1-4-5-6-7- oooh damn, let me try again.
(breaking glass noises)
Me: ummmmm... 8-1-2-4-1-4-5-6-8-6-4-9-0-0-5-2-3-2-5-3.... Shoot! Blew it again. Let me hit the cancel key.
(gunshot and my dog yelps once)
Me: THOR! OMG... 8-1-2-4-1-4-5-6-8-6-4-9-0-0-5-2-3-2-5-4-0-3-4-5-2-1-5-6-7-2-3-4-5-.... ARGGGGH.
(heavy footsteps coming upstairs)
Me: HURRY!!!... 8-1-2-4-1-4-5-6-8-6-4-9-0-0-5-2-3-2-5-4-0-3-4-5-2-1-5-6-7-2-3-4-8-1-5-9-0-5-4-3-4-5-8-2-0-1-2-8.... JEEZ!!!!
(bedroom door creaks open)
Me: 8-1-2-4-1-4-5-6-8-6-4-9-0-0-5-2-3-2-5-4-0-3-4-5-2-1-5-6-7-2-3-4-8-1-5-9-0-5-4-3-4-5-8-2-0-1-2-6-3-2-4-5-6-7.... (gunshot) AUUUUGH!!!!.....and I only had thirteen more digits to go....
In the form of an smg or pistol, having to change out your barrels to reload sounds really ineffective.