_Measure for the Stock._—Now measure for the drop of the stock, which is illustrated in Fig. 23. From the line _a_ to _b_, which is a continuation of a line along the top of the barrels, may be, for instance about three inches. Cut the stock away on top to this measurement, and fit on the butt plate. To get the length of the breech, measure from the spot where the end of the front trigger will come, and this measurement extended, straight back to the centre of the butt, gives the length. For a person with long arms about fifteen and a half inches is enough; about fourteen and a half for a person with ordinary length of arm, and thirteen and a half or thirteen and three-quarters for a person with short arms. _The Butt._—The depth of the butt for a double or single may be about five and a half inches, but for a light single gun a little less but not very much. _Letting in the Locks._—The locks should now be let in their proper places, and, while so doing, have great care that no more wood be removed than is necessary. See that the lock-plates have all the support possible where they fit into the wood. Cut out enough for full play of the mainspring and sear-berg spring carefully, do not remove wood where the edges of the lock-plate come, so as to leave open spaces for admission of water, dust or moisture. In letting in the locks the portions of wood to be removed can be ascertained by touching the prominent parts of the lock with oil, or holding the lock over a smoky lamp, so as to have soot adhere, then observe where it touches, on pressing the locks into place. Observe if the cup of the hammer comes squarely on the nipple, and put in the side bolts as they are to remain. _Letting in the Trigger-Plate._—Let the trigger-plate into the stock so that the arm of the sear bears wholly on the thick of the trigger, and not on the outer end. For this reason, if it engages the outer end, on being pulled to disengage the nose of the sear from the tumbler notch, it produces a sort of “twisted leverage” which does not work quick and strong enough to properly disengage the sear without some effort on account of this. If the arm of the sear bears only in part on the thick of the trigger, it works hard and stiff, and the parts soon wear each other. Observe if the arm of the sear be not too short, for it might happen that the trigger will slip off at the end upon a quick pressure being applied, leaving the parts disengaged and the hammer standing at full-cock.