Semi-automatic features can be eliminated from a weapon that originally had a bolt carrier that was reciprocated by a gas tube communicating with a barrel. After eliminating the gas tube, a carriage and pushing member can be taken from a kit and installed on the weapon. The carriage is reciprocatably mounted at the barrel forward of the bolt carrier, with the pushing member connecting between the carriage and the bolt carrier. The carriage can be manually reciprocated to reciprocate the push member and the bolt carrier.