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Sadlak Scope Mount Tips and Instructions


  1. PREPARATION Remove stripper clip guide from receiver (see below). Inspect for burrs and remove with file or stone. Instructions for properly removing stripper clip guide,
i. Remove receiver from stock. From the inside of the receiver, insert a 3/32 diameter or slightly smaller punch and gently tap the spring pin out. Do not attempt to remove pin by pushing it into the receiver because of possible burrs on the inside. Next, support the left side of the receiver with a block of wood. Gently tap the stripper guide on the right side only. Stripper guide is removed from right to left. ii. CAUTION: Care should be taken not to use excessive force to remove pin or stripper clip guide. It may cause the receiver to crack or other damage to occur.
  1. PREPARATION 2: Remove white square packaging cardboard from Hex Screw(3). Remove and temporarily place screw and Cam Washer(2) on bench.
  1. INSPECTION: Check if the tapped hole in the receiver has good threads by manually threading the Hex Screw(3) into the hole (do not use a wrench). Damage to receiver or Hex Screw(3) may occur if threads in the receiver are dirty or damaged. If threads are good and clean, the screw will easily thread into it. If it does not thread easily by hand, first clean with solvent and small brush then, if required, chase thread with a special #12-32 UNEF (Extra-Fine) screw. A chase tap is available from Sadlak Industries LLC for a small fee or the special extra fine tap can be purchased at an industrial supply company (Home Depot, etc. will notcarry this special extra fine tap).
  1. INSTALL SCOPE MOUNT(1): Place scope mount in the Receiver Groove on the left side(see Fig.4, Drawing 2). Slide mount toward barrel then back several times to check surface contact between the inside surface of mount and the receiver's left side. To help see actual contact between the mount and receiver, it is best to use Prussian Blue Paste (also called high-spot marking paste). The paste is non-drying, non-staining, and water soluble for easy cleanup (available through Sadlak Industries LLC - see price list.) The Left Side Key (see Fig.3) on the mount should fit completely into the Receiver Groove and when pressed firmly against the receiver, no light should be visible between the mount and receiver. A positive full contact between the mount and the receiver left side will help assure maximum reliability, will help maintain zero when the mount is removed and re-installed, and will prevent loosening of mount due to the heavy recoil forces.
NOTE: Manufacturers of receivers for civilian use (M1A) do not have to adhere to the government GI blueprint specifications and are not inspected using government gages. This has sometimes resulted in poor out-of-spec. machining of the left side Receiver Groove. The groove could be too deep resulting in a looser fitting scope mount or too shallow resulting in left side key on the mount not being able to be fully seated into the groove causing the mount to not rest flush (slightly cocked) against the receiver's left side. A poorly machined receiver groove may or may not work with the scope mount. It depends on the degree the receiver is out-of-spec. If the groove is slightly undersize, the mount will fit poorly, make it difficult to adjust scope to zero, amy cause loss of zero should the mount be removed, and may cause the mount to loosen more easilt. The Left Side Key on the Sadlak Scope Mount is precision machined to just fit into the smallest groove tolerance on a GI M14 rifle. They are machined this precisely for reliable zeroing and positive mounting when purchased by the US Military.
  1. INSTALL CAM WASHER(2): Insert Cam Washer(2) into elongated slot in left side of the mount. Position tab at twelve o’clock as shown in Fig.2 (Drawing 1).
  1. INSTALL HEX SCREW(3): Apply Loctite threadlocker #222MS to Hex Screw(3) and insert thru Cam Washer(2) then carefully hand start screw into receiver. Partially tighten screw with 3/8 box wrench approx. 1/8 turn past hand-tight to allow mount to make full contact with receiver yet still be able to slide towards the stripper clip guide angle face. Note: it is important, at this stage, for the mount not to have contact with the receiver Angled Face (see Fig.2 and Fig. 4). A small light gap should be visible. This assures the Angled Face does not influence the positive contact on the left side between the mount and receiver. This positive contact is very important for long-term reliability.
  1. CAM MOUNT TOWARD ANGLED FACE: Lightly tap the tab on the Cam Washer(2) with a plastic mallet clockwise until the above-mentioned light gap (step 6) at the angled face is reduced as the mount contacts the receiver. Keep tapping to allow the mount to ride up the angled face while the Hex Screw(3) remains moderately tight. You may notice the mount only contacts the angled face at a couple high points. This is often normal and caused by the variation in the manufacturing process and tolerances of the Angled Face. The original GI blueprint did not hold this angled feature very accurately because the only function, at the time, was to mount the stripper clip guide. Civilian M1A manufactures often hold this feature even less accurately.
  1. PREPARE CLIP GUIDE KEY(4): Remove two small set screws in the key (see Fig.1)and apply Loctite #222MS threadlocker. Re-install into key until flush.
  1. INSTALL CLIP GUIDE KEY(4): Slide key into Dovetail Slot (see Fig. 2 & Fig. 4) in receiver. Visually align center-threaded hole in key with hole in mount.
  1. INSTALL CLIP GUIDE SCREW(5): Thread screw into the Clip Guide Key(4). Partially tighten ¼ turn past hand-tight.
  1. LOCK KEY INTO DOVETAIL SLOT: Screw both set screws in the Clip Guide Key(4) until contact is made with bottom of the dovetail slot in the receiver. Partially tighten 3/4 turns past hand-tight.
  1. FINAL TIGHTEN SCREWS: Using an inch-lbs torque wrench, final tighten the screws to the following specifications in the order listed:
1) Hex Screw(3): 60-65 inch-lbs, 2) Two set screws in the Clip Guide Key(4): 20 inch-lbs Warning: Use caution when tightening setscrews. DO NOT OVER-TIGHTEN. Receiver may crack if excessive force is used. 3) Clip Guide Screw(5): 30-35 inch lbs
  1. FRONT POST SUPPORT: Screw down Fr. Post Screw(6) (see Fig.1) until contact is made with the top of the receiver. Turn 1/8 max. past contact point.
  1. LOCK FRONT POST SCREW: Remove Fr. Post Set Screw(7), apply Loctite #222MS threadlocker and re-install. Tighten to ½ turn past hand-tight.
  1. INSTALL RINGS AND SCOPE: The scope mount installation is complete and you are ready to install the rings and scope. Note: It is recommended checking and re-torqueing scope mount screws after the first 1000 round fired.
Remember to apply Loctite threadlocker #222MS or equiv. on all screws. A NOTE ABOUT M1A RECEIVERS Sadlak Industries LLC takes pride in the precision and workmanship of the products we sell. These scope mounts are based on the original Brookfield Precision Tool mounts previously purchased by the military. They are precision machined to fit on any M14(military) or M1A(civilian version of the M14) rifle that has been machined to the original GI specifications. Unfortunately, not all current M1A receiver manufacturers adhere to the GI specifications particularly in the area’s of the stripper clip guide and left side surface and the left side horizontal groove. Older receivers have a better track record. If your M1A receiver is made correctly, this scope mount will fit against your receivers left side perfectly. The key on the inside of the mount will seat into the horizontal groove with only a small amount of play and the inside surface of the mount will rest flush, with no gap or visible light showing, against the machined surfaces on the left side of the receiver. If your mount does not fit this way then your receiver is not within GI specifications. According to the GI receiver drawing #7790189 the 60 degree groove on the left side should be .070/.078” (per blueprint) wide at the bottom and .149/.153” (calculated from gage point) wide at the top. Our study shows that the GI groove is tightly machined with a tolerance or play of only .004 in the vertical movement. If your mount does not fit correctly, it’s most likely this groove is not within GI specifications and is cut too shallow resulting in a groove that is too narrow. To get your scope mount to fit perfectly with assured zeroing, Sadlak Industries LLC can machine the inside key of your scope mount for an additional charge. Please call for pricing and shipping procedures and to check if we have in inventory (non0GI spec.) mounts that have been specially machined with a left side key which is narrower to fit "out -of-spec" M1A receivers. IMPROVEMENT TO THE BROOKFIELD DESIGN While the original Brookfield mount was an excellent design and served our troops well, we have made some small but useful improvements. To prevent the Clip Guide Screw(5) from loosening we have adding two set screws to the Clip Guide Key(4) to positively lock the key into the dovetail slot. To give greater mounting flexibility on M1A receivers manufactured by other companies, we have slotted the hole for the Clip Guide Screw(5) and added a larger counterbore. This prevents the dovetail slot and angled face for the stripper clip guide from influencing the positive and higher priority mounting to the left side of the receiver. The Front Post Screw(6) has been increased for a larger contact point in the front. This resulted in an added benefit by reducing the number of hex key wrenches required for servicing from three to two.


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