I decided to put this in GD because guns happen to be somewhat controversial. I'm about to start keeping a small store open late at night for my family, it's a record shop that also sells gifts of all sorts (mostly hippie stuff) as well as pipes and hookahs. I think the business would boom if it stayed open for later, but I'm worried about the types that might come in at 11-12 at night (during the day is scary enough sometimes). So should I have a gun when I do this? I'm thinking it should be open carry just so people can see it when they walk in (would this affect sales?).
You will, first, want to consult some of your local laws. I'm not sure how business property is treated when dealing with the various carry laws. Usually, you're allowed to have a firearm on your property (so long as it is registered and you have any licenses that go along with restrictions on ownership). This is usually your home, where you can freely carry any weapon you own without a public license.
Things might get a bit quirky, however, with a business. I do not know. I am not a lawyer, and police officers are not always up to date on the laws (though I'm not one of those either, I just work with a bunch of them).
In either case - I do not recommend anyone use a firearm for self-defense without taking courses for that weapon and getting familiar/comfortable with the weapon. Far too many people get a firearm and, because they are not comfortable with how to use it in a case of self-defense, they pull it in situations they shouldn't or simply handle it improperly. This increases the chance of accidents and news headlines that demonize all of us who own firearms.
Most of my training in the military has focused on when not to shoot a firearm as opposed to when. I've had the "deadly force traingle" and the 7 justifications for deadly force beaten into my head ad-nausiem. I'm pretty sure I babble the things in my sleep. Why? Because we deploy overseas - where people get exceptionally pissed when we shoot someone on one of our bases (then they start demanding that we get removed from the area, and their governments start trying to kick us out... and we lose a strategic position... one idiot with an itchy trigger finger can threaten to compromise the strategic picture... like when those idiots raped a woman on Okinawa).
If you're in favor of such a thing, then recommend me a model if you don't mind, I'm going with a Glock though because the police use it. Also, I've never owned a gun before; plus I hate guns, I prefer fists if something goes down (I'll always win with fists xd). In fact, I actually can't believe I'm even considering this, if you told me a few months ago that I'd be carrying a firearm, I'd have literally rolled on the floor laughing. >.>
My recommendation is that you take a firearms course. If it is a good course, they will help you select a firearm that is more comfortable for you to use (you are not necessarily going to feel as comfortable with - or shoot as well using the same model a 110lb, 5'2" female is) and more applicable to your purposes.
I'm not a handgun person, myself. I've never felt very comfortable with them in a civilian environment. Sure - when I have it in a secure holster, it's alright - but those simply aren't practical for carry in most civilian environments (unless I want to go around looking like Rambo). To me, it's just far too awkward of a weapon to have sitting in your backpack, a cargo pocket, purse, etc - it's not readily-accessible for self-defense, and too easily separated from you (I'd always be paranoid that someone else would use it).
We're trained, when someone makes an attempt for our weapon, to jump straight to deadly force. It satisfies the capability, opportunity, and intent requirements - if they get that thing, it is 99% certain they are going to use it to cause you or someone else harm. So the idea of leaving it in a bag that is not practically grafted to my bone is just nerve-wracking.
I'm a rifle person. Adaptive Combat Rifle all the way (6.8mm chambered variety). You can't always keep it attached to your person in a civilian environment - but it's also much less awkward to have propped nearby (for me, at least). If they are too close for that weapon system, then they are close enough for blades or physical strikes.
Handguns, as we use them in the military, are more for use when you've exhausted the ammunition for your primary weapon. There are a few situations where you'll draw your handgun - but someone can sprint the effective range of that weapon in a very short order of time. A lot of people can be on top of you from 15 yards away before you can get the safety off (you have to be very versed in drawing your weapon and operating on the quick-draw to be able to pull it off).
In a store environment - you have a table between you and an assailant... but you still have to think about where you're going to keep this thing, whether you are going to keep it in condition 1 (safety on; round chambered - all you have to do is flip the safety and a double-action trigger pull will fire the weapon: this is the condition all officers and service members carry their weapon in unless in an area where the host nation prohibits it... there is one such place, and we all thought it was ridiculous - our side-arm was really only useful as a club) or condition 3 (safety on; chamber clear, loaded magazine inserted - you must cycle, "rack," the weapon and disengage the safety before you can engage a threat).
How long will it take you to access your weapon? What is the likelihood that someone else will gain access to it? What will you do with it when you go to other areas of the store?
A lot of these are questions you will only be able to answer after you get more familiar with the weapon and talk to instructors of self-defense courses who can give you some more targeted advice. They might be able to give you some other pointers about things you can do to reduce the likelihood that someone will cause problems in your store to begin with.
