Now my rant-ngine got started up.
Judging by design features - these guns are FNIX-made and the AI been toying around these prototypes (hence “experimental”). Being tiny war machines in form of fancy guns they sure being very sophisticated.
Case of Exp. Kpist - it’s action is “simple (straight) blowback”, that means bolt operates on the recoil alone and bolt “locks” by means of recoil spring jamming round into the battery.
A tiny motor with oscillating rod is all the difference. Just like that - on/off the tiny motor.
There exist guns (mostly MG’s ) that use electric drive on bolts for variable fire rate (usually by regulating the motor speed). This kind of gun is possible, except for power source circa late 80’s.
Why not other guns?
A case for shotgun is it’s special ammo. Right way would be “this shotgun can be fed only this ammo”, where’s fun? Otherwise - it’s same pump shotgun, but mildly “mall-ninjed”. Gun itself likely to be standart, but ammo is fantasy.
A case of M/49 - well duh. A “back” round kicks “front” round out of way. I can’t think up any reliable way to load RPG/rocktet launcher same way and have one shot per one trigger pull (unless it’s electric rim-fire with electronics on trigger, which isn’t popular within military). Ammo is standart, weapon is plausible.
A case of “Incediary” G3. it’s either have “super hot ammo” and all that fancy stuff is cooling gear or the gun heats up standart ammo as it pass through barrel. Lingering burningn of bullet hole is hard to explain (molten bullets?..). G3 is that simple to allow metal oven inside foregrip. If “cooler” - plausible, If “oven” - fantasy. Heating may be result of strong oscillating magnetic field (“levitation melting” principle) - relatively to barrel the magnetic field is constant, but aligned in different directions in different points. Relatively for bullet - it’s oscillating magnetic field.
A case of Glock. Fantasy gun with likely fantasy ammo. Remembering how car battery’s are EMP bombs (which is BS), then with pistol shoots tiny charged capacitors.
A case of pvg 90. I don’t know about how standart .50 BMG bullet reacts to magnetic field, but I suspect same case as exp, shotgun - a special ammo for special weapon. A cartridge, based on dimmentions of .50 BMG, actually very long and heavy. The projectile is launched by igniting primer and then coils along all the barrel’s length accelerate the “bullet”. If standert ammo is also susceptible to magnetic field, then
already powerful kick is enhanced further by coils. Thing is - the humming is coming from coils. Coil guns are very sophisticated due to timing of coils’ cascade pulls. Same humming also indicate that colis are “pre-charged” and ready for power spikes.
A case of MAG. Hands down - fantasy gun. I suspect that tiny generator powers both bullets and drive motor, that runs bolt.