I don't know shit about smg design autism but I'm tempted to learn for the sole purpose of being able to participate in one of the few non-shit threads on the grind page. Godspeed streloks.
>You gain nothing for that extra recoil that isn't made redundant by the existence of intermediate rifle cartridges(especially 5.56 NATO and 5.45 Soviet).
Out of longer barrels this is true enough, but when we're talking SBR lengths, it seems to me that some of the more powerful pistol cartridges have 5.56 beat in terms of muzzle energy and sectional density, with the added advantage of not breathing fire.