Dropped by
the bullet conversion
Load the cheapest basic rounds you own and the gun upgrades their behavior for free. You get the flat trajectory and the extra travel speed of high velocity ammo without paying for it, which matters at range because your shots stop dropping and start landing where the crosshair actually is. What you do not get is extra damage. The numbers stay tied to whatever you loaded.
what to feed it
Only the plain rounds get converted. Chlorophyte, ichor and the rest pass through untouched and keep their own tricks, so in practice you carry two kinds: cheap ammo for clearing, and something with an effect attached for a target that actually matters. Buying high velocity rounds specifically for this gun is wasted money.
where it fits
It lands at the point where the Uzi has stopped keeping up and slots straight into the same role with a better feel. Reforge toward Unreal. The gun is accurate enough already that the parts you notice are the speed and the tightened spread rather than the raw damage bump.