So what exactly is the point of all this?
We are talking about skirmishes between individuals, not larger armed militia, national guard or policing unit. That takes out most opportunities for supporting functions (machine guns, mortars, etc.). But it also tends to limit the some other roles: sniping would still be useful, but urban sniping is typically used as a way to ambush larger forces. Sniping in very small engagements tends to take more the role of an offensive strategy. A prime example that comes to mind in the Clanton-Earp feud (think O.K. Coral) where the Clantons took out one Earp by sniping, and disastrously failed in a latter attempt.
One important item to recognize: in a potentially dangerous situation you will have all sorts of encounters with various groups and people. The most dangerous ones will be the ones that occur up close. We can turn up close into a further two zone: let’s say really close and close: up to 7 yards, and out to 100 yards. They will be even more dangerous if there is some element of surprise involved.
At 10 yards you can throw a spear, or axe and a dodging will be difficult. You can close to contact in less than 2 seconds. If you turn and run there is very good chance that you will can be tackled: of hit multiple times by someone firing 6 or more pistol rounds.
At 7 yards you have an immense advantage if you have surprise. As you may recall from number 2, when the Shawnee used trickery to get up close, not a single settler survived the encounter.
What works within this zone? Weapons with a high cyclical rate of fire, and shotguns. With the very quick closure rate and minimal distances you want to be able to stop your opponent before they can in turn damage you. So the speed of fire does balance somewhat with speed. But if you have someone coming at you with a knife in close with a .30-06 bolt action rifle, and you don’t stop them with your first shot, you are now have a clumsy club in your hands rather than a gun.
When you get to out to 100 yards, the effectiveness of a number of weapons drops off drastically, all your hand held melee throwing weapons, and your pistols become of very limited value. Your shotgun can still be effective with slugs, but it losses that in-close shredding effect of a tight pattern of buck shot.
At 100 yards, your various long arms do not need to adjust for wind or drop. You are still in the zone where you are very much at risk, and rate of fire (ROF) counts. Within this zone that you get a lot of arguments about which long arm are the most effective. It is still close enough that even your more inaccurate assault rifles can hit and the M-16s (Ar-15) and SKS bullets will still likely due their tumbling tricks to maximize their damage. But your larger rounds will be able to nullify a lot of the oppositions cover advantages: you can shoot them through a tree, or house, or block wall. If they have some type of body armor, it is less likely to be proof against the heavier rounds. If burst or automatic weapons are available it adds considerably to the firepower within this range band, but very little beyond.
As you go from 200 to 300 yards (the middle zone) you are getting into the area where the combat effectiveness of all weapons against alert opponents drops off considerably. For various weapons it drops off more quickly than others.
But here is where you get into another argument of tactical effectiveness. You are starting to get into bolt-action territory. And here the argument is often as much one of expense as effectiveness. The semi-automatic (particularly .308 Winchester/762 Natox51 and larger) can still hit. But their speed in firing advantage is pretty minimal. So as the range increases past 100 yards, the bolt action comes pretty close to being the same weapon as the semi.
Finally you get to the area beyond 300 yards. Fighting can occur at these ranges, but it is difficult to hit. The larger caliber and more powerful rifles have a clear advantage over the lighter weapons provided the user is skilled enough to hit what they are aiming for. Hitting a moving target with a normal rifle gets to be very difficult. You will usually only get one shot. If you were in a military unit, this is where you would effectively be using your squad machine guns, light mortars, grenade launchers etc.
So what is the final point?
If you are going to get killed, it will probably be at a relatively short range. You need appropriate volume and power to win and win quickly.
If you want to attack someone at minimal risk to yourself, you want to do it at a distance. The further away you can attack a target from, the less likely you will be injured when they fire back. A somewhat exception to this rule would be if you have night vision capability, and they do not. At which point, you will be able to fire at them from 100 yards, and they probably won’t be able to see the end of their barrel. But you are still at a sufficient distance that they cannot effectively strike back.
Where you weigh these two options says a lot about what type of weapons you will choose, and how you will act.