_How to Straighten a Gun Rib._—Gun ribs, as received from the manufacturer or dealer, are more or less crooked and winding and must be made straight before being fastened to the gun barrel. Sometimes this straightening can be done with the hands alone, by bending and twisting the rib. If there are short crooks, the hammer must be used. Select a hammer that has a flat pene and this pene must be “across” or at right angles to the handle. See that the pene is not too sharp, but smooth and rounded at its edge. Place the rib to be straightened on a piece of hard wood plank, or what is better, get a piece of two-inch plank about a foot wide and long enough to reach from the floor to a height a little above the work-bench, say about the height of the top of the vise. It may be held in an upright position by means of a screw passing through it into the bench, or it can be so held by setting it on the floor and clamping one side between the jaws of the vise. On this hold the rib, lengthwise with the end of the plank, and using the pene of the hammer, strike blows on the inner or curved side of the rib. Do not strike hard enough to dent or bruise the rib so as to show on the opposite side. By a little practice a rib can be made very straight and true. _How to Fit a Rib._—Sometimes one side of a rib is longer than the other. Fit it into a properly shaped groove in a piece of board, clamp it so as to hold firmly and file away the longer side so as to match the narrow one. The clamps can be made of two pieces of wood placed on each side of the part to be filed, holding them and the rib with wood screws, the rib being moved along as a portion is filed. _How to Fit a Rib to an Octagon Barrel._—To fit a rib to an octagon barrel, file the portion where it comes in contact, square across so as to have all the surface possible to touch the barrel. To fit it to a round barrel, file lengthwise with a half-round file, and so file that the outer edges will fit close, leaving the inner edges a little open, or not quite touching the barrel. A half-round file for fitting ribs to round barrels should have the tang bent toward the flat side so that when the file handle is put on, it will not interfere with filing.