Regarding the Judge, I will attempt to sum up Paul Harrells thoughts over the course of his 5+ videos on the subject by putting the following words in his mouth:
"If you need to defend yourself from chocolate bunnies at point blank range then its a serviceable tool. If your assailant poses a threat equal to or greater than that of a pumpkin then there are better options."
I think your obvious concern about stray rounds is wise and understand why a 9mm might seem like a good idea. While the effective range is very short though the potential maximum range for the round to travel is much greater. Given the considerations you have expressed it still might not be a wise choice if your neighbors are 1/4 mile or less distant. Attempting to take all your concerns into consideration (sound, sizes and skill levels of operator, relative steadiness, range, etc) it seems that a small gauge shotgun loaded with shot is really the only choice.
Not a bad analysis! However, while I would like to lower risk (of a .223 round casing going astray and causing an unwanted injury or worse, 3000 yards out), a much reduced risk may be more rational than trying to get to near zero risk. As a close but not exactly parallel example, light loads from small shotguns are not allowed for hunting deer — for good reasons, even tho’ accidental shooting deaths by hunters (mostly of other hunters) would seem likely be reduced by such.
If I could cut the projectile flight distance of the .223 round by half, that reduces the danger area by a factor of 4. (The risk reduction in my specific area is greater because of where the roads are and are not - however, the squared function is better for a general analysis.)
Cont’d in next post...
Cont’d...
This brings me to a question to which the available information is to me a bit muddled. Taking our two most discussed options for example, it would seem that effective range (effective targeting) of the 9mm carbine is about 100 yards, the .223 is usually cited at 400 - 600 yards. (The .223 is the better choice of the two for sure in the SHTF scenario!) What I guess I’d call “risk range” (of an unintended injury to someone) is as you say much greater: The .223 is sometimes cited with a potential of 3800 yards or so: Over 2 miles. I’m still a bit confused on that number for the 9mm, but I think we are talking about a mile, perhaps?
HOWEVER! Those numbers state no elevation of the muzzle. No way under any scenario besides an attacker that has me “down” or true SHTF stuff am I ever firing either rifle on my property at an elevation above “0”. I suppose some sort of ricochet might elevate a round’s trajectory, at some loss of velocity, regardless, for now that goes in the “I’m already worrying too much” bin.
Distilled, my practical question is: Open, level terrain and sea level clear weather conditions assumed, how far will a typical 9mm round fired @ 0 deg. from a 9mm carbine 5’ high travel B4 it hits the ground? Then ditto that question for the .223?