In general I find representation of automatic weapons in game quit accurate. They use less powerful bullets therefore lack armour penetration but made up for it by high rate of fire.
Accurate to what? Any machinegunner would laugh in your face. The Bren Gun, the German MG42 and MG-3, the US M-60 and M-240, the iconic PK, not only do they fire full size rifle cartridges more powerful than modern assault rifles, they do it on automatic and for long spans of time. Heck you can go even bigger. The Browning M2 machine gun fires the .50
BMG round (already in-game, used by the AMR) at around 500 rounds per minute. The Russian KORD fires a comparable round at even higher rate of fire, and was specifically designed to be man-portable. Bigger? M-242 Bushmaster autocannon, fully automatic 25mm high explosive/armor piercing goodness.
Still have pesky super mutant problems? Wheel out your GAU-8, an unholy torrent of 30mm depleted uranium and high explosive projectiles guaranteed to saw anything you point it at in half.
Automatic does not equal "less powerful".
Isn't full auto fire and accuracy kinda opposite to each other?
To a degree, but nowhere near as bad as is shown in games. The effective range on a medium machine gun is in the hundreds of meters. Accuracy improves dramatically by using short bursts (3-5 rounds), and steadying the weapon on a bipod or a wall or the edge of your hole, or even your assistant's back. And even firing from the hip ("walking fire") is more accurate in reality than games typically show: sure there's an initial wild spray, but then you can balance the gun on its own recoil. It becomes basically a constant force that you can resist and compensate for. Just watch for the points of impact and adjust aim accordingly. (This works better in real life than it does in games, since in real life people will tend to seek cover in the face of a near-miss while AI has zero self preservation instincts.)
So.
If you're going to argue about
game balance as it applies to automatic weapons, please do not confuse game balance with reality. Fully automatic weapons are powerful and accurate.