5.45x39.5 vs. 7.62x39...hmmmm?
magazines are the same price and availabilty in my area.
wolf ammunition is, within $10 per thousand, the same price in my area. availabilty is the same in my area...yours may differ.
i am currently shooting 1940's 8mm mauser ammo from turkey. TURKEY!!!
now, compare russia's, bulgaria's, poland's, east germany's and lord knows who else's 5.45 production numbers against turkey.
i seriously doubt there will be a shortage of supply in my lifetime.
now, let's talk ballistics.
5.45 wins the fast and flat race. accuracy is only a bit better than the old m43 round, but the trajectory makes it easier to hit things.
will it (5.45) stop a human being better or penetrate more steel? i don't know. i don't shoot humans and armoured personel carriers. i shoot paper.
the issue is a moot point for me. if the shit is so deep that i'm worried about stacking bodies i'll make it up as i go.
i can tell you that fmj civvie 5.45 scares the hell out of me. it tumbles rapidly.
shot placement...or even getting a hit...is far more important than "will it knock down a 300lb., blue helmeted, ballistic armor wearing storm trooper" to me.
the real world advantages to the m74 round are: increased accuracy and hit percentages. it's just flat easier to shoot! the low recoil (especially if the rifle has a genuine commie ak-74 brake) impulse make rapid shooting and follow-up shots easier.
if "bugging out" is of any consequence to you (it isn't to me) you should know that for the equivalent weight, 5.45 allows you to hump more rounds.
lastly, let's discuss range of target engagement. in the 'real' world 300m is stretching it for a akm in 7.62. the ak-74 stretches that window to 400m. although i feel BOTH numbers are optimistic for the sights provide on a standard ak, let's just say that the ak-74 offers more usable reach.