Heavy-Duty
Universal
AR-15 80% Lower Receiver Jig
Instructions
Page 1: ...Heavy Duty Universal AR 15 80 Lower Receiver Jig Instructions...
Page 2: ...1 1x Top Plate Al 6061 T6 2 1x Right Side Plate Alloy Steel 3 1x Left Side Plate Alloy Steel 4 1x Front Support Al 6061 T6 5 1x Rear Support Al 6061 T6 6 1x Buffer Support Al 6061 T6 7 1x Drill Templa...
Page 3: ...Bit 2 19 64 Drill Bit 5 5 32 Drill Bit 3 3 8 Drill Stop Figure 2 Jig Fabrication Kit The additional tools needed to finish the 80 AR 15 Lower Receiver 1 Router Laminate Trim Recommended 4 9 64 Allen W...
Page 4: ...e spring and detent from the Modulus Arms AR 15 Lower Parts Kit may be used Optionally Modulus Arms offers an AR 15 Front Takedown Kit To install the Front Support using a Front Takedown Kit follow St...
Page 5: ...ce of the lower then further turn clockwise until the three screw holes are aligned vertically as shown in Step 3 Using two of the long screws attach the rear support as seen in Step 4 Do no tighten y...
Page 6: ...er the Rear Support and Front Support as shown in Figure 6 Use four screws to attach the Top Plate to the Rear Support and Front Support Tighten the screws to 1 ft lb Now tighten the screws attaching...
Page 7: ...upport Screw into the Right Side Plate and all the way through into the Left Side Plate as shown in Figure 8 Tighten to 1 ft lb Do not install the 20 x 1 5 Rear Takedown Screw Note Many questions have...
Page 8: ...versal AR 15 80 Jig Instructions 8 Figure 6 Vise Screws Drilling the Holes Drill Template Place the Drill Template into the Top Plate as shown in Figure 9 Thread two screws into the locations shown in...
Page 9: ...o labeled on the Drill Template Note If a hand drill is being used be sure to hold the drill upright If the drill is not held upright blemishes may be visible in the trigger slot after assembly Note U...
Page 10: ...12 Make sure the drill bit is inserted all the way into the slot and tighten the drill stop onto the drill bit Next drill the six holes labeled C in Figure 10 The holes are also labeled on the Drill T...
Page 11: ...uge in slot labeled B as shown in Figure 12 Make sure the drill bit is inserted all the way into the slot and tighten the drill stop onto the drill bit Next drill the two holes labeled B in Figure 10...
Page 12: ...ontrol Group Remove the two screws holding the Drill Template to the Top Plate Do not remove or loosen any other screws Remove The Drill Template from the Top Plate Insert the Router Template into the...
Page 13: ...h hard against the template A gentle touch is enough Mill the rounded corners in the template last as they are most likely to chatter When the opening is the same size as the template turn off the rou...
Page 14: ...anuary 14 2016 www ModulusArms com Heavy Duty Universal AR 15 80 Jig Instructions 14 Figure 15 Fire Control Group Depth Setting Figure 16 Fire Control Group Router Placement Figure 17 Fire Control Gro...
Page 15: ...Jig for Milling Rear Shelf and Trigger Slot Remove the four screws connecting the Router Template to the Top Plate Remove the Router Template from the Top Plate Rotate the Router Template around and i...
Page 16: ...ate A gentle touch is enough Mill the rounded corners in the template last as they are most likely to chatter When the opening is the same size as the template turn off the router wait for it to compl...
Page 17: ...www ModulusArms com January 14 2016 www ModulusArms com Heavy Duty Universal AR 15 80 Jig Instructions 17 Figure 20 Rear Shelf Router Placement...
Page 18: ...template A gentle touch is enough When the opening is the same size as the template turn off the router wait for it to completely stop and remove it Adjust the router base so the end mill is at the n...
Page 19: ...80 Jig Instructions 19 Drilling the Hammer Trigger and Safety Pin Holes Insert the Rear Takedown Screw Insert the Rear Takedown Screw through the rear takedown hole in the Right Side Plate and tighten...
Page 20: ...the Safety Hole Clamp the Top Plate into the vise so the Right Side Plate is facing up Insert the 3 8 drill bit into the drill Drill the hole shown in Figure 24 through one side of the lower receiver...
Page 21: ...Trigger and Hammer Pin Holes Insert the 5 32 drill bit into the drill Drill the holes shown in Figure 25 through one side of the lower receiver Do not drill all the way through Flip the jig over and...
