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Removal & Installation of Rear Sight
Tools needed: 3/32” punch, hammer, grease, sharpening stone (fine) approximately 3” x 5” in size, and needle-nose pliers.
Step 1 – Secure rifle or upper receiver so both hands will be free.
Step 2 - Using the 3/32” punch and hammer, remove the rear sight pin (roll pin) located just below the elevation drum in the upper receiver. This will release a large spring located under the roll pin – remove the spring. Measure the spring. Use a set of wire cutters to cut spring in half. Only one-half of the original spring is needed when installing your new rear sight.
Step 3 - Start turning the drum to raise the sight up, keep turning until the sight housing is elevated completely out of the upper receiver. Note: There is a spring and ball located on the left side of the sight housing in front of where the word “UP” is engraved. Ensure that spring and ball are retained for re-use.
Step 4 - After the sight base is taken out, carefully slide the elevation knob out ensuring you capture the spring and ball located under the front of the knob. That spring and ball is what gives you your “clicks”. They will also be needed for installation of your new sight.
Step 5 – Ensure upper receiver area is free of all dirt and excess grease.
Step 6 – Remove the elevation drum from your Northern Competition sight. Attempt to slide it into the receiver slot where you took out the old drum. If the drum does not fit into the slot, and it probably won’t, you will need to use a sharpening stone to fit the knob to the receiver. On the top and bottom of the drum you will see a step. This is the part of the knob that is to be stoned away. Using a drop of honing oil, place the knob in the center of the sharpening stone and place one finger on top of the knob. Using a circular motion, stone equal amounts off the top and bottom until the knob fits into the receiver slot. It should be snug but there should be no tight spots.
Step 7 - Clean off drum and put a little grease on the bottom side of the elevation knob where the ball rides in the holes and a small amount in the hole for the spring and ball. Replace the spring and ball in the receiver and carefully put the drum in place while holding the ball in place by inserting your punch down through the hole in the upper receiver directly above the spring and ball.
Step 8 - Put the spring and ball back into the rear sight and carefully insert the sight into the upper being careful not to loose the rear sight ball. Make sure the sight is straight and start to turn the drum to lower the sight in the upper.
Step 9 - Use a pair of needle nose pliers and a hammer to reinstall the cut half of the spring and roll pin (rear sight pin). First start the pin, then put the spring in cut side towards sight aperture or towards carry-handle and compress it until the roll in will go through.