I would go with ONE rifle if it is your first combat rifle and either a good AR or AK will fill the role and I am more than happy to explain this view. I am a little bit AK biased but I will try to stay impartial here. Also I am a very foresight orientated gun buyer and by that I mean, before I think about a purchase I ask, “how will this gun fill a role for me in the next few years and is that role worth what I’ll spend on it?” So with that said, I’ll go through how I’d run down those options in my mind if I were in your scenario. (mag weights not calculated, just what I’m using for sake of comparison, no need to rip me a new one over it loaded 30 ar mag~ loaded 30 ak mag ~ loaded 20 M1A mag)
The M1A SOCOM: Since this is my first “battle rifle,” It is most likely what I will have to take with me if I have to bug out due to zombies/government collapse/red dawn style invasion. With a dry weight of about 10.5 pounds, and loaded mags weighing maybe a pound a piece, carrying a 180 round load out will mean 20 pounds of my carried weigh devoted to my primary weapon. Not to mention this load out is likely to cost me $2000 or more. This combined with the idea that I may pay $.50-$1.00 a round to practice with this rifle, I may spend another $1000 training to get proficient with this rifle. Yet another point is a large fast bullet like that is used rather inefficiently if I can only get 4 MOA out of the box with this rifle. With all that weight and work, plus the possibility that ball ammo is going to drill thirty cal holes in soft targets up close, I don’t think this will fill my need effectively.
The AR-15: With the same scenario in mind, this weapon has some distinct advantages over my other two choices. Over the M1A SOCOM, it has the advantage of being more accurate (on average), a more comfortable mag capacity, and a swift yaw-happy round that is much cheaper to train with. Over the AK, it has accuracy. It’s potential performance allows me to engage targets at ranges like 500 meters. Over both of them, it stands out in weight with it’s puny average of 6 pounds. That means a 180 round load out will only cost me 14 pounds meaning I could carry six extra pint’s of water over the M1A! It’s adaptability and track record also add to the allure. It’s only drawbacks maybe it’s tendency to not eat dirt as well as it’s soviet counterpart but hey, I’ll clean it religiously! Or maybe when I get time…
The AK-47: With all the same factors in mind, I think it’s time to disqualify the AK-47 completely… and replace it with the AK-74! Hey, the Russians updated it, why should I buy the old model? With it’s distinct improvement in recoil over its older brother and that wicked nasty bullet that likes to turn, twist, rip, fragment, tear, rupture and downright obliterate flesh all in just a few centimeters, I like it. And at $319 for 2000+ rounds, how can I say no? Okay, It may not be a tack driver at 500 meters but I could probably hit an approaching zombie/marauder/commie paratrooper at that range with a few shots… probably… that being said, I can afford to take those extra shots because the ammo is so cheap. Also, I can fill the action full of zombie guts, sand, or mud and a few thousand youtube videos says it will shoot! Sounds like a plan! I just hope minute of torso accuracy is good enough…
And there you have it, my rant! And the reason I say get one rifle is, you are better off to spend that extra money on mags and ammo to get proficient with the weapon. Besides, you only need to carry one at a time!
I hope this gives you a different perspective to look through because this is all strictly my opinion, not necessarily scientific fact. Just some thoughts...