If you are forced to rely on guns in X-men, you are super weak sauce...
Laura takes the bullet and regens it.
Jean catches the bullet and sends it back at you.
Anna (when/if she gets the powers of Captain Marvel) just stands there and takes it.
Juggernaut laughs at you and then crushes your skull.
Sentinels are entirely unaffected by small arms fire.
With an angry mob, you might kill or wound one or two, but then they beat the shit out of you.
Seriously develop some decent powers....we believe in you Null!