I already thought about this exact question and bought a Colt 6920 M4 5.56x45 for normal defense etc. I also keep a CMMG .22 conversion drop in kit/bolt in my B.O.B. for anything else. A .22 is too important to leave out of any survival plan as is a real defensive weapon/MBR. This way I have both.
I know you could have a Ruger 10-22 for what that kit costs but the question was "what single gun".
I know you could have a Ruger 10-22 for what that kit costs but the question was "what single gun".