Crossbows were effective for fundamental reasons I understood from personal experience. My father back on Earth had been an antique collector who'd insisted on showing me his hunts with historical weapons during our wilderness trips. The experience had been educational, if unconventional.
Unfortunately, I had never participated in the hunts themselves, but I did watch. Anyways, the mechanics were straightforward: the string gets drawn back using hand strength, a lever, or crank mechanism, then locked into a catch called the sear.
A short projectile , called a bolt sits in the groove along the stock in front of the drawn string. When the trigger releases the sear, the string snaps forward, transferring its stored energy into the bolt and propelling it toward the target.
