Adjusting Length Of Pull On Synthetic Stocks

One of the more common jobs a gunsmith faces daily is the addition of a recoil pad or adjusting a stock’s length of pull. Length of pull is defined as the distance between the trigger and the face of the buttplate or pad. The addition of a recoil pad will require cutting a section off the butt of the stock equal to the thickness of the pad if you are to maintain the original length of pull.

The mechanics of installing a recoil pad on a wood stock have been covered many times in just about every book on gunsmithing but many new gunsmiths and hobbyists are scared off by synthetic stocks. There really is no need to be intimidated by them as the basics remain the same, although they will offer you new challenges. To get an overview of several different manufacturer’s stocks, I contacted the folks at Brownells who were generous enough to supply several stocks from the major manufacturers for us to examine.

I was fortunate to have stocks from Advanced Technologies, Speed Feed, Bell & Carlson, Choate, Hogue, and an M4-style collapsible stock to examine and compare. There are many others on the market but I thought this was a fair sampling of what you can expect. The stocks had a lot in Far common regarding construction at the rear.

All but the Tapco were hollow in the butt area, all were injection molded and had ribs molded in along the top and bottom of the inside of the stock to provide a place for recoil pad screws to find purchase. This feature made installing a pad much easier than if those ribs had not existed. After examining the stocks and removing the pads supplied by the manufacturers I realized that each stock was going to require the gunsmith to do a little innovative thinking.

All the provided pads were screwed on and required nothing more than a Phillips screwdriver to remove. The exceptions were the Tapco and the Bell & Carlson. The Tapco had no pad and the Bell & Carlson was both screwed and glued to the stock. The Bell & Carlson pad was permanently attached and normal force did not allow the pad to be removed, dictating what could be done and how to do it. Let’s start with it and discuss the process.

The Bell & Carlson stock came with a 14" length of pull from the face of the trigger to the face of the one-inch soft rubber recoil pad with a hard plastic base. To shorten the LOP (Length Of Pull) I simply used a saw to cut the rubber section from the plastic base that was permanently attached to the stock, effec-

Tabs are easily removed so a commercial pad or buttplate can be fitted. tively removing 7/8" of length. From that point it would be quite easy to face off the plastic plate and install a buttplate, rifle pad or any available thickness of recoil pad to adjust the length from approximately 13.25" to 14.25". The the stock needs to be shortened further, handle like a wood stock by cutting the stock and fitting the pad. As straight forward as the Bell & Carlson job was the others presented some interesting problems.

The Speed Feed and Advanced Technologies pads have what I will calla raised alignment core that fit into the hollow area in the buttstock. I assume these are put there to speed assemble as it is fast and simple to put the pad into position and run in the screws without worrying if the pad is properly aligned to the stock. In both of these stocks, shortening by replacing the pad with a thinner pad or buttplate is no problem as they do have two screws that will hold the new pad just as they do on a wood stock.

Those raised alignment cores only cause problems if you decide to cut the stock and reuse the old pad. My advice is not to. I cut an inch off the end of one of the stocks. Because of the taper of the bottom of the stock the end of the stock was shorter and also smaller than it was at factory length. In order to get the raised alignment pad to fit into the now-smaller opening it was necessary to use a rasp and make it smaller too. That is not a difficult job and only took a couple of minutes.

The problem came when I started grinding the pad down to fit the stock. The raised alignment core was molded into the pad and was quite close to the surface. As I ground the pad I broke into the core much as

The recoil pad will be screwed into these ribs. Bottom Even though painted black to match the pad, this is unacceptable and the solution is to install an aftermarket pad rather than trying to salvage the factory pad. This score must be trimmed to fit the smaller stock after cutting. you would if you ground too much off an aftermarket pad with a metal reinforcing plate in it. The result, even when painted to match the color of the pad, is unprofessional and ugly.

The best bet in this case is to simply fit an aftermarket pad. The Hogue stock presented a slightly different problem. Rather than a raised alignment core on the pad, it had tabs molded into the stock that fit into cavities in the factory supplied recoil pad. In this case those molded-in tabs disappear when the stock was cut or could be removed to fit a thinner pad. We face a different problem with the Tapco M4-style stock.

It’s hard to imagine anyone wanting to shorten the five position collapsible buttstock further and doing so would be a real challenge but making it longer is simple. The plastic buttplate is a permanent part of the stock and is checkered to provide a nonslip surface when placed against One of the bigger problems unique to synthetic stocks rears its ugly head after you have cut the stock and selected the thickness of pad to the buttplate you want.

You may discover that the screws for the pad don’t line up with those moldedin ribs in the stock that the screws are supposed to screw into. With a wood stock this isn’t much of a problem because you can always plug the old holes and simply drill new ones to fit the spacing of the recoil pad Far This will almost certainly not match the screw holes in the new record pad. Far right next page: The paper template is placed on the pad. The top hole is positioned on the top hole on the pad.

The location of the bottom hole will have to be drilled where the pointer indicates. The bottom screw location supplied with the a pad will not be used. the shoulder. The easiest solution would be to glue a pad directly to this checkered surface and grind it to fit flush with the existing buttplate outline. A slightly harder but more secure solution would be to remove the checkering from the face of the butt and gluing the pad to the smooth surface.

you are installing. On the synthetic stock you can make a template by placing apiece of paper over the butt and marking the edges of the stock and location of the ribs. Then take the template paper, lay it on the pad, and mark where the screw holes need to be. Drill the base of the pad and put screws in it that will line up with the ribs in the stock. If you find that impossible with the stock and pad combination, the alternative is to fit a spacer at least 1/4" thick over the end of the stock.

Countersink wood screws so the heads are flush or below the surface of the spacer and spaced so they fit onto the ribs in the stock. Then the screws of the new pad are screwed into the spacer and the whole assembly is ground to fit. A gunsmith has to be innovative, able to look at a problem and devise a solution. Manufacturers design their products for their ease of assembly without regard to what you or the customer might want to do after the product is sold.

As a gunsmith, that is what the customer is paying you for. As a hobbyist, that is your challenge. Ain’t that just grand? AG American Gunsmithing Association