12ga. AR-10

[fightingquaker13]

And here I ask ...Why? If you can't get it done with 9 rounds of 00, are 11 more going to help you? The way I look at it, the shotty is for home defense. I doubt you'll fire more than four rounds before it's over one way or another. If I need to go beyond that I'll pick up the AR. No mag issues or strange ammo required, just 30 rounds downrange. Just my .02.

[tombogan03884]

The first answer that pops into my head is that 12 Ga gives you more options such as tear gas, bean bags, slugs, buckshot, etc.

[Solus]

More ammunition allows the weapon to handle more situations than personal self defense.

Without to much fanciful imaginings, we can envision riots, gangs, looters and flash mobs. 

Some folks will be considering the need to use their weapons for "homestead" or neighborhood defense in survival scenarios.

If you plan for any of that, having a shotgun, or any other weapon, able to deal with it along with personal self defense is the goal.

[Magoo541]

Those that have exchanged fire never complain about having too much ammunition. 

[tombogan03884]

Looks like I misunderstood FQ's question, I thought he meant why 12 ga rather than 9mm or some other caliber.
Why bunches of 12 when you could use smaller ?
Some people think "bigger is better" ?

[Sponsor]

[MikeBjerum]

And here I ask ...Why? If you can't get it done with 9 rounds of 00, are 11 more going to help you? The way I look at it, the shotty is for home defense. I doubt you'll fire more than four rounds before it's over one way or another. If I need to go beyond that I'll pick up the AR. No mag issues or strange ammo required, just 30 rounds downrange. Just my .02.

Because many stages are set up to require 15 - 20 shots, and reloading shotguns on the run is a pain.

[tombogan03884]

I went back to the OP, Then I looked at the MKA 1919

http://en.wikipedia.org/wiki/File:Akdal_MKA-1919.JPG

And saw another reason.
With this, you can have a 22 plinker, a 5.56 carbine, a .308 precision rifle, and a 12 Ga shotgun all with the same action and the same controls located in the same places .
Train on one the .22, shoot and maintain all of them.

[Ranger Dave]

oh H*ll Tom that makes too much sense, we can't do something like that

With this, you can have a 22 plinker, a 5.56 carbine, a .308 precision rifle, and a 12 Ga shotgun all with the same action and the same controls located in the same places .
Train on one the .22, shoot and maintain all of them

Ranger Dave