CAPACIDAD PARA LA COMUNICACIÓN Y EL TRABAJO EN EQUIPO

rail slots.

Figure 151- Shows using a carbide end mill to adjust and true the edge level of a hard, or more than slightly irregular, slide bottom after first indicating position. This method is very useful when surface irregularity is found where the recoil spring plug housing extends from the slide. Make multiple light cutting passes.

Figure 152- Shows finishing a slide bottom by hand, using a l/2"xl/2"x6" fine cut stone.

Many slides will require no more than moderate leveling and dressing with this type of stone.

But some will be found with irregularities that require truing by file. Harder civilian slides should be milled as shown in figure 151.

Slide Bottom Preparation When the frame rails are to be lowered and tightened, the slide must be predimensioned for proper frame fit. The rails also must be prepared and dressed to prevent bind or sticking on the frame.

1. Check slide bottom height using a depth micrometer and a measuring reference plate inserted between the inside slide rail slots. For accurate measurement, the reference plate must fit snugly.

2. With most slides, slight bottom variations, burrs, and high spots can be easily leveled with a fine stone.

3. When irregularities and high spots are found that won't reduce with moderate stoning, file the slide bottom area until true. See figures 151 and 152. Harder slides may require milling.

4. After truing, stone and dress the slide bottom until it is smooth, level, and parallel with the slides' rail slots.

5. Measure the remaining slide rail slot to slide bottom thickness. When in operating position, the bottom surface becomes the new foundation line which determines just how low the frame rails must be. See figure 150.

Caution: Don't polish or alter the final slide bottom surface once the frame rails have been lowered.

6. After frame rail work has been completed, the slide will be tightened to remove side play- dress and deburr the inside rail shoulders now.

Use a l/2"x1/2" fine stone for this work, and remove burrs and high spots only.

Frame Rail Forming and Gauging Bars

After slide truing work has been finished, and the slide bottom has been polished, the resulting slide rail thickness dimension is measurable. This measurement, taken from the new bottom foundation line to the top of the slide's rails, determines just how far the frame rails must be lowered.

Now, the correct size rail forming-gauging bar can be selected. Standard gauge bars are machined, hardened, and precision ground in several even sizes; .115", .114", .113".

.112", .111", .110", and .109".

The first four are most often used. The last three are mostly needed when a slide's bottom condition is uneven, and requires extensive truing.

Half-size bars such as .1145", .1135", .1125", and etc., are used by some pistolsmiths to minimize metal work; a very good idea.

Using Frame Rail Forming and Gauging Bars

Peening or swaging frame rails down to a gauge bar is a skill requiring patience and careful attention to detail.

Expertly done, the underside of new rail bottoms will be nearly as straight and even as if machined. In theory, a series of small, even taps on the rail tops can gradually form an almost mirror like impression of the gauge bar held in the frame rail slot.

While developing this skill, it's a good idea to practice on older frames, reducing rail height in steps, while using successively lower gauges.

Figure 153- Shows both single and double-side rail forming and gauging bars. These hardened, surface ground bars are used as an inside frame rail forming die by holding them inside the rail slots as the rails are peened, or swaged lower.

The bars are also useful as a measuring device for checking rail slot height and condition.

Figure 154- Shows a single-side rail forming and gauging bar inserted into the frame's ran slot, placed just as it would be when the rails are lowered. Gauge bars should be pre-selected at a size approx. .001" over actual needed slide rail height. While developing a "feel" for this work, use bars .002" over as a first step.

Figure 155- Shows the four rail end areas that are lowered when the modified rail peen-down method is used. Only a top rail area equal to the frame's slot depth should be lowered. Most rail slots run between .060" and .065" deep.

Trying to peen down a wider area of the frame may damage the frame or work harden the rails.

Figure 156- Shows the frame in the vise, set-up between aluminum frame plates, ready for rail peening or swaging. A reinforcing insert, or filler, is. used in the magazine well to prevent frame distortion when the vise is tightened. I suggest using a small lead or wood block under the frame to hold it in vertical position.

The Modified Peen-Down Rail Lowering Method

This method replaces the old full length rail lowering system and prevents damage to the thin middle rail areas on both sides of the magazine well. Full length rail lowering is hard to learn and always carries a potential for frame damage. Also, it has been discovered that lowering the middle area doesn't improve performance. The important requirement, as it turns out, is to provide tight, consistent, repeatable lock-up, and with a minimum of vertical and horizontal slide clearance.

Approximately 7/8" of each rail end should be lowered.

See figure 155. Peen only that portion of the rail just above the slot. Trying to lower a wider area requires too much force and, again, increases the potential for frame damage.

Frame Set Up

While there are quite a number of ways to secure the frame while the rails are being modified, the use of aluminum frame plates allows maximum holding power at a minimum of vise pressure.

Leather protective pads can be used to preserve finishes.

See figure 156.

Much less vise pressure is necessary when the frame is supported underneath. Use a soft lead or wooden block for this purpose. This simple step, when combined with the insertion of a magazine well filler, helps prevent frame compression damage.