Nice, but not a need and not a firearm.
Too basic, too limiting, and too inconvenient.
If I were limited to one gun for survival I would choose a Stevens/Savage model 24, .357 mag over 20 gauge.
Wouldnât moisture in the atmosphere condense on a cold surface?
If you want the inside of the pipe to be and stay dry as possible, it should be filled with air that is as cold as practicable when you seal it. When you bring that cold, sealed pipe back out into warm moist air, there could be condescension (temporarily) on the outside of the pipe, but inside the pipe, the relative humidity will actually go down as the cold dry air warms.
No, not in the right hands. Youâve only got about 30" drop at 150 with a 50yds zero.
At 400 and beyond though you might as well be lobbing mortar shells.
I think Iâd go for the .22hornet/20 or 12g like they issued to the LR WWII bomber pilots.
Not much of anything you canât kill with one of those.
The colder the air the less moisture it will hold.
The idea is to have something left to be able to eat it after you kill it.
The hornet is a pretty mild cartridge and with any shotgun youâre not going to blow up your target unless youâre just a few feet away.
The choke and load has far more to do with the outcome than the gauge.
I shoot almost the same exact load in each of my 28âs, 20âs, and 12gâs. One to 1 1/4 ounce of either 6âs or 8âs and he same for waterfowl with larger shot.
http://gundata.org/cartridge/3/.22-hornet/
About twice the velocity of the .22m and usually a 60-75gr bullet. Not too big or powerful for small game, quite adequate for deer at short-med range and will even kill a Moose or Elk with a head/neck shot at 100yds with the right bullet.
Definitely a need. You know how a gunshot is a bear call in Alaska?
Bows arenât.
You have also created a considerable partial vacuum. It might be better to partial pressure with CO2 or better N2.
M6 Scout?
âŚ
A gunshot is a predator call pretty much everywhere in the rural US.
One evening late I shot a deer in the middle of a wheatfield. I went and gutted him and drug him out.
An hour later after dark I shot three coyotes feasting on the gut pile.
The next morning I shot four hogs feeding on what was left of the coyotes and gun pile. 20 minutes later I killed another coyote coming to investigate the pigs that were still in the field.
When I go to NM or CO with buddies that have drawn an Elk or Mule Deer tag, I get tags for cats and bears so I can hang around for a day or two unting predators after they leave.
Sounds right. If I remember right they came in 22 hornet and either .410 or 20g.
I own a Springfield Armory M6 in 22lr/410. Quite the handy and damned useful thing.
A flip top area of the stamped sheet metal stock holds something like 15 22lr and 4 410 shotshells. It has a dual sight with rear peep for the 22, and a buckhorn V for the 410.
It used to be parkerized, but now rusty and mostly painted black. It is all steel except for the plastic insert which holds the various cartridges in place.
It breaks in half with one push-out pin.
I wish that I had 3 of them!
I had to go do some looking just to ârefreshâ. They came as M4âs and M6 survival rifles and all I see on GB right now are .22lr/.410 or .22H/410 but I could have sworn they also came in 20g.
I know there were other more modern versions in both .22h/20 and .22h/12g from other mfgâs so I may have them confused.
You may want to keep yours under cover if the bbl length is 14" or under as they have been classified as NFA items/SBRâs.
Nope, mine is more recent and all good with the regs. Itâs just been hanging out on the ATV in all sorts of bad weather. 
Bears can smell your kill regardless of how you killed it.
They really like apples too, but they cannot smell them from as far as they can hear a gunshotâŚ
No, you have created pressure. When the cold air that was in the tube when you seal it warms up, it expands and pressurizes the sealed container.