When Firing Guns with MWC, weapon swing sound will plays in the background, while it doesn't fire anything from the guns but when near blocks/entities it will breaks/hits them.

Tried adding the MWC Class to the blacklist, not working. Temporary work around is just switching to other hotbar items after shooting to stop the weapon swing.

Removing BetterCombat Fixed this

Maybe you just tag wrong class , for me I tried tagged multi class and it's worked for me.

Here's my tag,

    com.paneedah.mwc.weapons.Guns
    com.paneedah.mwc.MCW
    com.paneedah.weaponlib.Weapon

Ah I see, thank you for the help. It is fixed now.