Infantry combat in the Post-Cataclysm era is both very different and very similar to it's pre-Cataclysm counterpart. Different that each soldiers has a massive (comparatively) array of short-range drones, sensor data links, and other gizmos and gadgets to vastly improve the grunt's sensing capability. Add to the fact that almost every soldier in any military has at
least MMI implants and a cyberbrain (which can be used as a sort of 'lifeboat', which allows a soldier to be allowed to survive in situations that they wouldn't otherwise), which makes soldiers surprisingly versatile and effective in combat. Full-conversion cyborgs with power armor with their limiters removed is a
frightening thing to face. How frightening? Well, to give you an idea, one
platoon of full-conversion cyborgs can take on a
company of unaugmented soldiers and come back with nary a scratch, just needing a full ammo resupply. Even gene-augmented soldiers tend to be hard pressed to deal with a full-conversion cyborg. Full-Conversion Cyborgs are an uncommon sight, mostly due to their maintenance costs.
Most military forces utilize man-sized EW and ADS packages onto their power armor (usually mixing it in a squad to have half of them use the ECM while the other half use ADS), making man-portable 'smart weapons' absolutely useless. Every time man-portable 'smart' weapons gets improved, it was quickly countered with modified and/or enhanced EW and ADS packages. Anyone that's heavily reliant on infantry 'smart' weaponry will
not like fighting against any human force from the Post-Cataclysm era as their weapons will simply become useless. Thus why any Post-Cataclysm era military engagement is
extremely destructive, as 'smart' weaponry's effectiveness have been severely degraded. While fighting a force without these smart-weaponry degrading capabilities, the opposing force will find out that under such conditions these weapons are
incredibly accurate.
Most conventional small arms have completely converted to using Electrothermal Chemical tech, utilizing the Triple Coaxial Plasma Igniter branch. This allows for a far better velocity (up to and surpassing 3km/s) and fewer stoppages.
(an American Dominion 'pulse rifle', which utilizes TCPI (kinetic aspect) and 'Metal Storm' (grenade aspect) technology)
Small arms that utilize TCPI technology are called 'Pulse Guns'. The weakest 'pulse guns' tend to have a blue-white muzzle flash -and these weapons can fire a projectile at 2km/s at the minimum- while the strongest have violet-white flashes -which can have projectiles achieving velocities in excess of 4.5km/s. The lightest round masses in at 5 grams (a 10mm Auto style round, which at 2km/s has a KE of 10kj) while the heaviest is 50 grams (an HVAPI round for an American Dominion 12.7x105mm HMG, which at 2km/s has a KE of 100kj), which gives them extreme kinetic power even at the lowest velocities. It also ensures that these weapons are
incredibly bulky in terms of size (an unaugmented pre-Cataclysm human can barely use an Assault rifle outside of semi-auto
and a setup that makes the most powerful of anti-material rifles look absolutely pedestrian) and mass, but this is offset by the fact that only those in power armor are wielding it. This also has made any non-military cover (i.e. constructs that are military grade) only effective as concealment.
A far less
demanding (for some measure of
less) weapon is the various laser rifles that are in service since the early 0140s.
(the American Dominion Wattz series laser rifle, fully loaded with a thermal clip magazine, an older Metal-Storm style grenade launcher, and a fully charged power cell)
Laser rifles were slow to become commonplace in the Post-Cataclysm era, mostly due to the fact that the lasing arrays that were made up to that point couldn't even
hope to cope with the required energy in such a small package. A few breakthroughs in miniaturizing and hardening the lasing arrays that
could changed all that, but to get them that small required a lot of their cooling systems had to be removed or otherwise downsized. That is where the thermal clip came into play. Each energy (most of which are laser rifles, although some
plasmoid weapons exist... they're incredibly rare outside of the American Dominion) or electromotive (i.e. coil/railguns) weapon utilizes a simplified cooling system that dumps all the heat into an eject-able heat sink, which after it is saturated with heat automatically ejects (or in some cases, forcibly ejected via the action that loads the first thermal clip of a thermal magazine). Most thermal clip designs automatically eject after two power cells and are mostly pulse lasers with the occasional continuous wave laser (but these chew up power cells like jet fuel). Each 'shot' is really a cycle of 10 laser pulses -usually blue, green, or violet part of the spectrum- that add up to the energy required to penetrate armor.
Any human being that gets hit by any weapon tends to be either chunky salsa or
a bloody smear across the floor.