Well, based on this platform, we (US) DO employ and deploy the Knights Armament SR 25. And, the British are using the LMT 308AR/ AR10. The original AR10 was and is still used by the Argentines, and a couple other small nations. It was used alongside the FAL in Rhodesia.
If you really know the AR10 history, the rifle was very good, and GTG for testing until the week before the official test, where they swapped the barrel for a carbon fiber wrapped ultra thin barrel for weight savings. And, it (The original) works pretty well. Except it can not take sustained heat because the epoxy winds up going soft, and the inner barrel will then swell and blow.
The originals' main drawback was the attempts to modify M14 magazines to fit the rifle. The M14 unit costs a whopping $9 back in the day, while the Armalite AR10 magazine ran about $35, and this was in the 1980's. To be fair, with the factory magazine, the rifle works well, and does not break down. The carbon barrel was a stupid stunt, and it cost them the M14 contract.
You can see how much the platform made an impression, because when it was reintroduced as the AR15/ M16....... the only thing left to say was "What M14???" The M14 is a good rifle. It throws a good round; a BETTER round than the 5.56, by far. But it has its' own issues, as does every combat rifle. And it's no weight savings. As to the FAL, they are really good rifles, but with their own quirks, so no one is to be outdone in the weird parts arena. I traded my SR25, at the right time, and it was WELL WORTH my while to do so. Lemme tell you; I would have run that rifle a hundred times over before I would hustle the M14 around for a month. And, if to compare to an FAL? There would be no compelling reason to go with the FAL. If there was no parts support?? Neither is prone to parts failure on a regular basis. So, day to day, there would be no benefit. As to accuracy??? The FAL would be a good bit behind the SR25. It's not better in any way to any of the 308 rifles I now have.
And; for the assumption that the M&P10 would be purchased to be a potential middleweight battle rifle for self defense/ EOTWAWKI rifle?? Look man....... whatever rifle and pistol you are carrying will be the last rifle and pistol you will ever carry. In this case? If I was in possession of the M&P10, and the world flipped on its' head? I'd load out everything into every mag, and then choose carefully what else I would store and where, and how. And I would walk out into the fray- a helluva lot better prepared than my neighbors. Tier 1, tier 2, shotgun, 22lr, 38snubnose revolver- ALL beat unarmed. Run what ya brung.
