Combination Guns

Combination guns used to be fairly popular, and they were huge in Europe. They're pretty simple, break open over/under guns intended for hunting. Usually a rifle barrel over a shotgun barrel, though the German dreilings had two shotgun barrels AND a rifle barrel. The benefit is pretty clear--you get the versatility of having a shotgun AND a rifle in one long gun. Very handy for going out hunting/foraging--with the right gun, you could engage any kind of game at basically range.
 
If you've seen the Springfield M6 Scout--a .22lr or .22 Hornet over .410--that's a combination gun. The Savage Model 24 is another example that started production in the late 30s and came in a variety of chamberings. Some of the 24s have a built in

Unfortunately, both are out of production, though I guarantee Springfield would sell a truckload of M6s if they brought them back. They can be found on the second hand market at widely varying prices.

I've been doing some looking, and there are a couple variants of the Savage 24 that look especially appealing to the survivor:

• .22lr over 12 & 20 gauge
• .22 magnum over 12 & 20 gauge 
• .30-30 over 12 & 20 gauge
• .223 over 12 & 20 gauge

My personal preference would be for the .223 or the .30-30 over a 12 gauge. The .223 is a flatter shooter with better range, cheaper, more common and already stacked deep for my AR. You can also get .223 to .22lr chamber adapters, which would let you use the full rifled barrel like an AR conversion kit. On the other hand, the .30-30 can shoot cast bullets, run on black powder, has a bit more OOMPH and I've got family/friends who stock the caliber.

Dave Canterbury has shown a lot of the versatility of the shotgun and ease of reloading in an "extended" scenario on his YouTube channel. The 12 gauge is never going to be a long range gun, though, and the ammunition is difficult to carry in quantity. Pairing a good rifle barrel with that extends your options--you'd have a hunting/foraging gun that could just about do it all.

Anyways, interesting option for hunting and long term post-collapse.

I don't have a 24 and have never personally handled one, so  if any of you, my faithful readers have experience with them, let me know. I also may be overlooking other makes/models of combo guns--let me know if that's the case. Would be groovy if there was a current production model of the right flavor.