Ok, I know it sounds like a silly question, so lets just get that out of the way . Uses: Plinking and target practice, and as a back-up long-range gun for SHTF uses. No specific hunting purposes, except in SHTF situations. I feel with two shotguns only, I need a Here are the reasons why I feel the .22mag could be an adequate substitute for the .223 for my purposes (for simply plinking or as a longer-range backup gun). 1) As far as accuracy goes, from what I've read, good exaples of both types of rifles, in stock form, shoot about 1MOA or a bit less. 2) As far as effectiveness goes, either is capable of a deadly headshot at up to perhaps 200 yards (probably more, but that is the max range I am realistically looking at), with the fmj .22mag ammo I'd use. This would naturally work on both medium 4-legged game, and on 2-legged targets. If zeroed at 125 yards, with the .22mag I'd see about 2" maximum rise, and about 12" drop at 200 yards, which is relatively easy to account for with a bit of practice. 3) "Knock Down" power for personal protection is not really needed, as I have a shotgun for that. If ever used against a dangerous target, it would either be simply for accurate covering / distracting / wounding fire, or to take down a threat that does not know I am there (in which case a head shot would be used). Here are some actual (though perhaps relatively small in the grand scheme) advantages I've come up with for the .22mag. 1) For both practicing and in a real scenario, the quieter report of the .22mag could be quite nice. When practicing, there is less fear of a .223 round overpenetrating / overshooting the target and endangering others, and the quieter report will attract less attention from those in surrounding areas. 2) You've heard me say this before: smaller ammo is easier to carry is larger amounts. I'd imagine I could carry twice as much .22mag ammo as .223 ammo. 3) If I pick up a .22mag revolver in the future (somewhat likely) as a BUG, the shared ammo would be nice. As far as cost goes, they both cost about the same (with bulk .223 being about as cheap as your average .22mag prices), so there aren't any real cost advantages to either. Then again, I keep telling myself "if you are going to get something different to serve a unique or other-end-of-spectrum purpose, make it different enough to be worth it!" The .22mag about doubles the effective range of my .22lr rifle, in good conditions where headshots are possible. However, everything the .22mag can do as a weapon, the .223 can naturally do much much better. Of course, it is easy to imagine many less ideal conditions in which the greater long-range accuracy, or the much greater power of the .223 would be handy (active targets making headshots difficult, windy conditions, etc). Still, I can also imagine cases where being able to grab a small pouch and have 100 rounds of .22mag would be nice, like if I ended up pinned down at a relatively long range, and needed the extra ammo to keep making accurate shots at the foe. I am leaning toward the .223 for the natural tactical advantage, but have been considering the .22mag for the above-listed logistical advantages it does have. If I get a .223 it would most likely be a Stevens 200, and the .22mag would likely be one of the Marlins. So, what do you guys think?