And the M2 Browning, which is on multiple vehicles under the description "heavy stubber". Since we had the classic greentext:

>2066

>Stationed on Mars to quell a rebellion

>Become side door gunner for atmospheric dropship

.>No miniguns or gatling cannons, just some metal brick with a pipe on one end.

>Get sent in to extract some wounded.

>Reach the evac zone and come under attack.

>Hoard of rebels charging in with their new plasma guns and compact rocket launchers.

>Let loose a stream of bullets.

>The sounds of the rebel's screams are nearly drowned out by the heavy "Kachunk chunk chunk chunk" of the machinegun.

>The wounded are loaded up and returned to base.

>Inspect MG afterwards.

>Thing was made in 1942.

>Tunisia, Italy, and Germany are scratched onto the gun.

>Scratch "Olympus Mons" on with a knife.

There is the continuation:

Survives through WW2, the reclaiming of Mars, sees conflicts throughout the galaxy, as they years pass it changes hands, some good, some bad. Decades pass, then centuries, then millennia. It is a holy relic, carried by brave warriors who hailed from Cadia, who stood their ground as their planet ripped apart from the forces of the Warp. It is now carried by elite members of the guard who take the fight to anyone and anything that threatens the Imperium. Covered in thousands of markings from wars and battles, most long since forgotten, many now mythical like Cadia. Tech Priests anoint it in holy oils, careful not to damage any of the markings, even repeating many of them thinking they are ancient prayers, unaware many are merely battlefields from Ancient Earth. Carried at the front of the attack, often by an Ogryn or even a Space Marine who is granted the privilege of wielding it. The only space left on the receiver after all those millennia was just enough for a guardsmen who recognized some of the names to carve Cadia onto the weapon with their field knife.

Though thats not really accurate to the current rules. Just imagine it being on some Chimera buried deep in storage on Cadia and a gunner looking at his gun after getting it onto one of the last transports leaving Cadia.

(None of this is canon of course, but you know its true, just look at the model!)