Keep in mind, if you bought a shotty with anything other than a bead sight, it's not going to fit in your mouth unless you cut the sight off. Also, if you bought something where the tube is the same length as the barrel (usually holds 8 slugs) it won't fit in your mouth unless you take the tube off.
So something like this is going to need some mods, or you are going to have to aim for the heart...
View attachment 82101
Whereas this is good to go right out of the box:
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Yes, shotguns are incredibly loud. Not sure if more than something like a 50bmg, but without a doubt louder than any rifle up to at least a 30-06.
Here is how 00 buck spreads over distance (
https://www.tactical-life.com/gear/ammo/00-buckshot-ammo-test/)
I selected the distances of 12, 30, 50, 60 and 75 feet for the test, as these run the gamut from close range to the maximum distance a standard 12-gauge smoothbore might perform. The rule for shotgun patterning has been that you usually get about 1 inch of spread for every yard from the target. At our distances this would mean:
12 feet = 4 inches
30 feet = 10 inches
50 feet = 16 inches
60 feet = 20 inches
75 feet = 25 inches
So at point blank to about a foot you're talking about 1" spread (the barrel is 3/4"). A slug is right about 3/4". That's why at point blank, it really doesn't make a difference.