INSTALLATION INSTRUCTIONS for .338 LAPUA DET MAG

Remove metal from stock and disassemble action. Invert the receiver and notice the magazine box mortise cut. At the rear of this cut, there is an island which houses the center guard screw. A cut will be milled .175" to the rear and .250" deep as shown in (figure 1). Remember to also open the rails up where the milling process has taken place. The cartridge rim needs to be able to fit through the rails at this most rearward point. The top receiver shown has been altered. Shorten face of bolt stop aproximately .175” to accommodate extra box length and allow the face of the bolt to get behind the cartridge rim when the bolt is in the rearward position. (figure 2)

The ejection port will also need to be moved rearward .250" to allow for correct ejection. Failure to do this will result in the cartridge case ejecting into the underside of the rear receiver bridge, thus hindering the ejection process.

The stock will need to be modified for the new trigger guard assembly. The magazine well on the new assembly is the only area that should require fitting. The trigger guard and front tang are the same dimension as the factory parts. Allow .010"- .020" clearance between the trigger guard assembly and the bottom of the receiver when assembled. The pillar lengths should be .800" at the front and 1.250" at the rear.

Click on the boxes below for a larger picture
                   

Fig.1 and Fig.2- Altered parts are shown on top.