My Shockmaster®

Instructions for the Shockmaster Sliding Comb Stock

Your new air cushioned buttstock will give you years of shooting pleasure. We offer the following instructions to assist you in the use of this product:


The recoil reducer does not need internal or external lubrication. The air cylinder is lubricated and sealed during manufacture. However, if you get oil (or water) on the unit it will not be damaged. Please note: Excess lubrication will show around the center guide rod in the form of a brownish lubricant after the stock is in use. This is normal and may be wiped away. It is not required for proper operation.

Air Adjustment

The recoil reducer may need additional air once or twice per year just as the tires do on your automobile.

The air in the recoil reducer may be adjusted by removing an access plug in the recoil pad, screwing on the valve extension provided, then using a standard American air compressor to add air. Please note: An air compressor with a tank works best. Those without a tank usually have a lever lock type air chuck which releases air from the cylinder when removed, making it difficult to accurately get air into the cylinder. Call G-Squared regarding an adapter for this type. The stock works best with pressures of 90 to 115 psi. The exact amount is not critical, however we recommend that you stay within this pressure range. You should have enough air so that you can comfortably shoot without collapsing the stock into your shoulder prior to firing. Most shooters fill it until it feels about right (usually around 100 to 105 psi) then forget about it. The exact amount of air is not of concern. If it's comfortable to shoot then it's working right and working for you. Do not be concerned about damaging the unit if you put in too much air. We have tested them to 220 psi and stored them that way.

When filling the stock with an air compressor nozzle (or chuck) learn to press the nozzle firmly on the filler valve and snap the nozzle off sharply when the desired pressure is reached. Practice helps. Try it a few times at home to get used to the way it operates.

Using the E-Z High Pressure Pump

If you have the E-Z HP pump do not use your valve extension. Thread the pump directly onto the recoil reducer valve until the gauge registers pressure and follow the instructions provided with your pump.

Comb Adjustment

The comb height adjustment may be accomplished as follows:

  1. Unlock the 1/8” hexagon head allen screw at the rear of the comb (one turn counter clockwise) using the T-handle hexagon key provided or any available 1/8” Allen type wrench.
  2. Using the same T-handle hexagon key or allen wrench inserted into the top of the comb, turn the forward adjustment clockwise to raise the comb and counter clockwise to lower the comb while raising or lowering the rear of the comb every turn or so with your fingers.

    Each turn will raise or lower the comb 1/32” plus or minus .005”. Once you have adjusted the comb to your ‘ideal’ height we advise lowering the comb to it's lowest position while carefully counting the turns and/or fractions of turns required to bottom the comb out. Make note of this number and it will always give you a proper reference and also allow you to return to a prior setting. In any case always raise the comb (clockwise adjustment) at least 1/4 turn from it's lowest or bottom position to preclude binding when firing. Do not adjust the comb upward beyond 1/4” gap between the stock and the comb.
  3. Retighten the locking set screw.


To install or remove the buttstock you must remove the comb. To do so, unlock the 1/8” hexagon head allen screw at the rear of the comb and turn the forward adjustment clockwise while raising the rear of the comb with your fingers until the rear of the comb clears the vertical steel post. (You do not need to remove the recoil pad from the rear plate or remove any screws to remove the comb.) Remove the T-handle hexagon key, turn the comb 45 degrees right or left, push forward and lift the comb off of the stock.

The rear assembly including the recoil pad may then be pulled away from the forward portion of the stock in one piece.

The recoil reducer and forward end plate may be removed in one piece by taking out three phillips-head screws (four screws used in some stocks). You will then have access to the stockbolt for installation or removal of the buttstock.