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Posted: 10/2/2006 2:59:10 AM EDT
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I have a front BUIS that loosened up. It's a YHM with two set screws on bottom. How do I get it centered on the barrel? (After my fix I couldn't figure how I wasn't on the paper.....I was shooting minute of berm!  )
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Interested to hear the answers too. I have a PRI and I did it through trial and error. After I "eyeballed" it center of barrel, I set my rear flips at the middle of the windage knob. Shoot. Loosen screws. Tap FSB left or right. Repeat. There must be an easier way though. |
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If you have a vise and some barrel blocks.. Clamp barrel infront of F-base lightly.Line up vise so that the muzzle points to a wall etc atleast 3-4' distant. Strap 6" level with rubber band to the bottom of recvr. Rotate upper in vise till level than snug vise. Take a black string with a weight & push pin to use as a plumb bob on wall , adj till it is centered in bore by bore sighting by eye. Mech zero rear site. With a T allen in one of the set screws look thru rear sight ap and rotate front base till front sight post is centered on plumb bob string. When centered tighten both set screws AND USE LOC-TITE this time ! ( red or green ) on both set screws and weep into front sight base barrel ring or rings. You can scratch/paint a witness mark also but if you use loc-tite it shouldn't move. |
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