The decision to “Bug-Out” will always be a difficult one and the conditions that would necessitate it are very hard to predict. In the worst possible scenarios, you may find yourself out in some pretty dangerous environments. In these situations a basic conceal carry pistol just won’t cut it and you may require something with a little more “reach” and “punch”. For this reason alone it is critically important to invest and train with some kind of carbine.
There are endless debates about the “best” survival carbine and caliber. In reality they all are effective for their intended use. The crucial differences lie in understanding the tradeoffs and selecting the weapon with the most acceptable compromises in the following categories:
- Overall Weight (Weapon + Ammo)
- Reliability
- Stopping/Penetration Power
- Effective Range
- Ability to Conceal
- Versatility
Overall Weight

Ammo is heavy, never forget to consider its weight in your Bug-Out planning.
In Bug-Out scenarios you may have access to a vehicle, but don’t count on it. You should be able to carry everything you need to survive on your person, including extra ammo and magazines. It doesn’t matter if you plan be out for a basic 3 day outing to scavenge and then return home to resupply or if will you have to hump your gear several hundred miles without any plans to return. In either case, weight is the principal selection criteria for your carbine.
One option to reduce weight is to look at carbines that that are chambered in pistol caliber rounds like the Beretta Storm (9mm, .40mm and .45ACP), the H&K USC (45ACP), and the Kel-Tech SUB-2000. These weapons are lighter and more compact than many of the other options and in this sense, meet many of the criteria for a Bug-Out carbine. As a bonus, with the right combination of carbine and pistol, your magazines may be interchangeable along with the same caliber of ammo.

This is one of my favorite pistol caliber carbines, the H&K USC chambered in 45 ACP.
Personally I would not recommend this as a solution however. You end up compromising too much in other areas like effective range and penetration power. Weight is still a factor, so we will have to look at other ways to get better performance and not exceed your overall all weight restriction.
If you insist on standardizing on a single caliber that can be interchanged with your pistol, the best choice would be the 5.7×28 cartridge. This is a very unique round developed for NATO as an extremely lightweight round intended for pilots to carry that is capable of penetrating modern body armor. The 5.7×28 cartridge can be fired by both the FNH Five-seveN series handguns as well as the FNH PS90 carbine.
Reach and Power
Even though pistol calibers are very light weight, for a bug-out carbine you really need a more powerful rifle cartridge. Your carbine needs to be able to reach out to around 100 to 200 yards with ease as well as be effective for close quarters combat, hunting and sniping. Pistol caliber carbines can be used, to a limited extent, for all these uses but they are at a significant disadvantage compared to rifle cartridges.
Common rifle cartridges are the 5.56x45mm NATO, 7.62x39mm, or 7.62x51mm NATO. Of these rounds I personally prefer the 5.56 NATO due to its lighter weight and general availability. Both of the other calibers deliver more stoping power but I feel that the trade off on weight makes a more than fair compromise. A single 5.56x45mm round is almost half the weight of the 7.62×39 and more than a third the weight of the massive 7.62×51 NATO.
Selecting a Gas System
When it comes to carbines chambered in rifle cartridges, there are essentially two different choices, “Gas Piston” Operated or “Gas Impingement” Operated. My preference is a “piston” style gas system because it is much more reliable, requires less cleaning, and is more forgiving with lower quality ammo. Gas piston system run cleaner because they don’t vent “dirty” gases back into the “guts” of the weapon; instead gas is blown out the front of the weapon.
I chose to go with the Sig 556 platform in lieu of the more popular AK-47 because it gives me the best of both worlds; a “gas piston” system in a carbine chambered in the lighter weight 5.56 NATO. Gas piston uppers are available for the AR-15 platform but they are not very common and don’t have the proven track record of a manufacturer like Sig Sauer. Similar system are also made by FNH with a model called the SCAR 16.

The FN SCAR is another option for a "Gas Piston" operated carbine chambered in 5.56 NATO
Trade-Offs with Barrel Lengths
Length of the carbine is the next important consideration. The minimum legal barrel length in the United States is 16 inches with some barrels extending out as much as 20″ and 22″. Anything shorter that 16″ is considered “Short Barreled Rifle” or SBR by the ATF and will require additional paper work to acquire.
The longer the barrel the better the performance at longer distances. A 16″ or greater barrel will easily get you out to around 400 to 600 yards and a 20″ or 22″ barrel can get you all the way out to as much as 800 yards with the right ammo, setup, and training. In my opinion you are not likely to need to reach out much further than 200 yards with 100 being the most likely distance so a 16″ barrel is more than long enough.
Concealability

Notice how my Sig 556 SBR virtually disappears in the front pocket of my Maxpedition Falcon II 3 day pack!
Keep in mind that the longer the barrel the harder the weapon is to conceal. Concealment is a greatly overlooked aspect of bug-out scenarios. Don’t assume that in a bug-out scenario it will be feasible to openly display your carbine. In particular in areas with some law enforcement still in effect or during the initial phases of a more serious SHTF scenario; you may need to keep your carbine hidden from the casual observer. The last thing you need is for your weapon to be taken from you by law enforcement or worse, seen as a threat and fired upon by them.

And the Winner is?
My personal recommendation is to get the shortest gas-piston carbine chambered in either 5.56 NATO or 7.62x39mm you can legally own and train with in your state. If you want less weight and more ammo go with the 5.56 NATO cartridge or if you don’t mind trading the weight, trade it for an AK-47 chambered in 7.62×39.
Either caliber will give you all the power you are likely to need in most situations and still be able to carry enough ammo and supplies to get you were you need to be. The shorter the barrel the easier a time you will have concealing it, using it in CQB and still have the option to “reach out and touch someone”.

Here is a shot of my Bug-Out Carbine - The Sig 556 SBR




