_Re-rifling._—One method of re-rifling is to make a rod with a mortice in one end to receive a rifling cutter or “saw” as some term them, and fix at the other end a handle like an auger handle, but so fixed that the rod will turn around freely no matter how the handle may be held. This rod is inserted in the barrel to be re-rifled and the cutter forced through one of the rifles, which must be deep enough to force it to follow its direction when pushed forward and pulled back until it would cut no more, it would be placed in another rifle and so continued until the circuit of the rifling is made. A slip of paper is then put under the cutter and a repetition of the process made and continued until the rifles are cut as deep as desired. If it be feared that the rifles, opposite to those where the cutter is at work, will be injured by its bearing upon them, a dove-tailed groove is made across the rod opposite where the cutter is placed, and in this is fitted a slip of wood that is cut to fit the curvature of the base of the barrel. If a bit of half-round file or a cutter be made to be inserted in place of the slip of wood, the lands can be finished at the same time that the grooves are being cut deeper. When barrels are so worn that the rifles have not depth enough to hold the tool described for re-rifling, another process must be resorted to. Make a rod of hard wood about six or seven inches long and so as to slide easily through the barrel. In one end of this fix the cutter. Around the other end cast lead or other soft metal so as to fill the rifles. It is evident if this short rod be forced through the barrel by means of a longer one, that it must turn with the rifling, being so forced to do by the soft metal engaging the several rifles. The operation of working being the same as previously described. CHAPTER XXII. ON GUN LOCKS. _Quality of Locks._—It is impossible to judge the quality of a gun lock by a mere examination, for if the metal be not the very best and the workmanship be also good, some portions, as a spring, may grow weak and in an unguarded moment give way. If the mainspring be not thoroughly tempered it may break the first time it be used on a frosty morning. It is well to see if the attachment of the stirrup or swivel be well made and fitted, as this controls the movements and play of the mainspring. The fitting of the sear spring on the sear is important. If too much cramped, it may give way; if not enough cramped, then it may grow weak and there will not be that sharp, clear click that the admirer of a good lock likes to hear.