The iconic M82 50 BMG Anti-Materiel rifle was at least initially invented for doing things like disabling a car from a distance, for doing damage to a radio transmitter, fucking up a parked helicopter or jet, intentionally detonating an IED, something like that.

Yes, you can use it as an anti-personnel rifle, but it is heavier, less accurate, and has a lower effective range, as well as a good deal more recoil, than actual sniper rifles designed to kill people or roughly human sized hunting game animals at an extreme range.

https://en.wikipedia.org/wiki/Anti-materiel_rifle

Basically, an Anti-Materiel Rifle is somewhere between an old school Anti Tank Rifle, and a Sniper Rifle.

So... contextually, unless you are a Vertibird, or in Power Armor... you are probably not 'made of materiel'.