For all the people clamoring about anti materiel rifles (materiel, not material. Comes originally from a French word and indicates army equipment), they are exactly what they are called. They are meant to disable (tl: wreck) enemy stuff from far away, meaning destroying (lightly armoured) vehicle engine blocks, detonating IEDs and generally shitting up stuff. They aren't anti-personnel weapons, either, as for that they are a cumbersome overkill (still works, ofc) for a less reliable result. Better just use a smaller caliber.
They also aren't used against tanks. Not MBTs, not IFVs, not APCs, nothing. That shit hasn't worked since the latter half of the second world war, as armour has easily outstripped them before they even really existed in their current forms. You might at best damage some luggage, or disable an optic, but getting through a plate is a bad joke. They also aren't meant for dug in fortifications (genuinely lol'd at that), because of an obvious reason called meters of hard concrete. Bunker busting is done with stuff that weights thousands of times both the gun and the bullet and wouldn't obviously be used, if you could dig into a mountainside with a rifle (srs, what are some of you smoking and where can I get it?). It'll penetrate some poor peasant's wall alright to kill the armed kid inside, but even a good foxhole isn't what it was made for.
Then again, this is a sci-fi rifle inside a fantasy world, so unless there are reasons to suspect otherwise or a plot inconsistency, I'd say whatever goes, goes.