I would think that would stop the carrier latch from operating correctly all the time, with each shot, but if it is missing the screw, it will most assuredly cause problems. The hulls rim makes contact with the latch each time, mashing it in, which releases the carrier to come up, and the bolt to come forward.
You might try placing a punch or pin, close to the screws correct diameter, in the screws place, and trying the gun to see if it works. Make sure it is long enough to easily pull out.