Okay, I'm going to be the detractor on the M1A and the Mini-14 (and variants). I know I'm new around the 'yard, but I've a quite a bit of experience with both of these guns.
The M1A is a copy (sort of...) of the military's M-14. The problem is that the M1A has a cast receiver rather than a forged receiver. When you shoot a forged gun you hear 'ping', when you shoot a cast gun you hear 'thud'. After several thousand rounds, my M1A started experiencing FTFs (failure to fires). Examination revealed that the headspace had changed, BECAUSE THE RECEIVER WAS STRETCHING! Yikes! I had the barrel turned back .030 and sold that gun ASAP. That firearm design was never intended for use with anything other than a forged receiver.
Now most people will never put that many rounds through their guns, and never have any real problems with them. But if you're serious about a quality gun in that pattern, you need a forged receiver. There are only two options. 1) Buy a forged Norinco. They are not properly heat-treated from the factory and will also experience stretching. BUT, you can send the gun to Smith Enterprises, have it properly heat treated, and you'll have a good semi-auto M-14 for under $1000. 2) If you're really serious, then you need to get LRB Arms gun. They're forging brand new receivers right here in the good old USA, and they're TOP quality. Their M25 receiver even has an integral rail forged right in! Pricey at ~$3000, but what's your life worth? <img src="/ubbthreads/images/graemlins/laugh.gif" alt="" /> I love mine, and believe it's one of the finest battle rifles that I own.
The mini-14 is another disaster, mostly suffering from poor workmanship and dismal barrels than anything else. I've put my borescope down several and they all look like the rifling was cut with a dull chisel. Absolutley the worst I've ever seen. Because it's a proprietary gun, you can't really get a quality aftermarket barrel (Hart, Douglas, etc), either. Even if the rifling was any good, the barrel is so thin that it makes any kind of accuracy impossible. Mine was a 4 MOA gun at BEST. What else? It was hell on brass, most of it being un-salvageable after going through that gun. Mounts and accessories are really tough to come by. Aftermarket mfgrs have largely ignored the mini in favor of the AR. I've got a lot of Rugers, and generally like 'em, but every mini I've handled was a real lemmon. I happily sold mine to an acquaintance that doesn't shoot much.
For a powerful battle rifle with a price that can't be beat, I'd go with a CMP Garand. Plentiful 'clips' and plentiful ammo will exist even after the SHTF. Parts are easy to come by. They were all well made by American machine shops. Any gunsmith worth a sh!t will be able to work on them in the unlikely it breaks. I love mine, and haven't ever gotten a bad one from CMP. The only bad thing is that it takes MONTHS to get your order, so be patient.
Jon