If by "gun" you are referring to the serialized frame that the govt. considers to be a firearm, then I have to say the AR platform. You can have calibers from .22lr up to a .50BMG on the same lower and barrels from 7 inches to 30 inches. Come to think of it, why do I have all these other guns?
I'll tell anyone who asks me, "what is the most diverse gun across the board"? My answer has not changed and probably will not unless I see something else. The standard shotgun is nearly indestructible. You can use it for home defense, hunting, sporting, and recreation. Believe it or not it really isn't that expensive to shoot either depending on what your shooting. Personally I would prefer something like my benelli auto shotgun rather than a pump. But I still keep my trusty pump guns near by and still use them. Very simple to use and clean. The only downfall is that you are constantly loading it when shooting. I plan to do the magpul dynamics tactical shotgun this summer is my schedule permits.
My Schmidt-rubin K31. has a 12 round mag for 7.5x55mm. ammo isnt quite too bad, plus its easy to chamber a new round with that straight pull bolt. and is a pretty accurate rifle
I am a Glock lifer. Having taken the Glock Armorer Course and having carried one since 1992, there is no looking back. I know if I have an issue that I can easily fix it. I am on my seventh Glock and have yet to have a problem with one of them.
Seriously no AK love? If I could only have one gun I'd have a suppressed draco sbr. Small enough to conceal, powerful enough to take down just about anything, light enough to carry comfortably, accurate enough to hunt or take down a man sized target at a couple hundred yards, reliable enough to hold up in the weather and rough conditions, enough capacity to lay down suppressing fire, short enough for cqb, and a mean enough sound when chambering it to make someone think twice about messing with you....
I voted for the .22LR.
Seems to be in last place??
1. A .22 rifle is probably the most common firearm listed.
2. The .22 LR ammo is the MOST common caliber (Probably World wide?)
3. The .22 LR caliber has taken (Killed) everything from Tweedy Birds to Cows.
4. Anyone can shoot a .22LR accuratly without any special training.
5. The .22 LR has been, and will be around when some of the others are long gone.
6. The .22LR caliber ammo can be bought for $.02 a round anywhere in the USA.
7. I do NOT recommend it, but the .22LR can be fired through a rifle without ear protection, with little/no hearing damage (??).
I could go on--The POINT is: The .22LR in a rifle (Or handgun) DOES have more going for it than any other of the choices listed..IMO--Of Course...Bill.
If I can cheat, an AR-15 with a 22 upper as well. I believe there is value in having a 22 that you can accurately shoot, however I don't want to give up the .223/5.56 firepower. Same lower, two uppers, two types of magazines. Cheating? Maybe.
I would choose a Glock 19. It can be carried on an ankle, pocket, on duty, or IWB with a light on the rail. My main concern is defending my family and I can't do that with an AR15 when I am shopping at Meijer' but the Glock is an always gun. In reality we can't pick when and where we get atacked and the G19 allows me options to carry it all the time.
Ryan
My Marlin 336. .30-30 is a proven deer rifle. If you hit a BG once he is going to go down and stay down. It's not particularly threatening looking and people are use to seeing lever actions in the westerns so you could get away with carrying it without scaring everyone. Easy to clean and built to take a beating. Reasonably short enough to maneuver in a house and long enough to use as a club if you run out of bullets. With practice you can fire quick and place good shots and you can top off the magazine with it at your shoulder.
I though about a handgun but as has been said many times, "a handgun is for fighting your way back to the rifle you should have had with you all along."