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Posted: 11/10/2010 11:38:21 AM EDT
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I have a RRA LAR-8. I mounted a Nikon 4.5-14x40 Buckmaster scope on it in an ArmaLite 1" mount. I used my boresighter on the back fence at approximately 20-25 yards, and I ran out of clicks before hitting zero. According to the boresighter, I still need to go down another 8-10 clicks to be on zero.
What do I do? |
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Quoted: I have a RRA LAR-8. I mounted a Nikon 4.5-14x40 Buckmaster scope on it in an ArmaLite 1" mount. I used my boresighter on the back fence at approximately 20-25 yards, and I ran out of clicks before hitting zero. According to the boresighter, I still need to go down another 8-10 clicks to be on zero. What do I do? First, what Assaulter wrote: don't panic. Second, I'm going to guess that you used an End of Bore Collimator to bore sight. That gets you on paper at 100 yards, not 25 yards. There's a huge difference here, and it's not just 75 yards. There is also a parallax error issue that the collimator can't compensate for. Your scope is probably also focused at 100 yards. That would be the best distance in which to zero. When you get the opportunity to zero at 100 yards, let me know if you still run out of clicks to adjust. If your base is close to perfect, your rings close to perfect, and your scope close to perfect, it should only take about 5 to 6 MOA of internal adjustment to have your zero. (That would be about 25 clicks if the scale is 1/4 inch per click.) If it takes more than that, then that's because something somewhere is causing the need to use more internal adjustment. At that point, you could try and remount checking to make sure that the base is true, the rings share the same center, and that the scope does okay in a on the bench box test. (You do that with the collimator since the collimator has a scale on it that you can follow.) |
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FWIW, I used a LaserLyte boresighter on my 24" HBAR and it was "dead center" (in windage) when I checked my Bushnell Elite 3200 10x at approximately 25 yards (after I zeroed the scope at the range at 50m). I would not rely on the laser boresighter for elevation adjustments in close proximities, but getting it "close" and "zeroing" the windage will reduce your time spent zeroing at the range. |
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Quoted: Thanks, that's some great information. I am using the Laserlyte bore sighter, and as you mention, it fits in the end of the barrel. I'll post when I get a chance to shoot it again. Trying to do a "bench" box test with a laser collimator will be pretty close to impossible, so skip doing a box test on the bench, and do it for realz (as you kids say!) Don't worry if all of the POIs don't make a perfect square. Something that's close enough is good enough. More to the point, the test is more about making sure that when you turn an adjusting screw the POIs are predictable. Otherwise if the adjustments are not predictable, then there's really no use in trying to adjust! Also, different scopes have differences in the range (in screw travel and the geometric relationship with the erector tube) that adjustments can actually be made and control by the spring. In other words, for example, say a scope lists maximum screw travel as 90 MOA (45 MOA up, 45 MOA down.) It may be that the spring's geometric relationship with the erector tube and the adjusting screws (commonly referred to as the "gimbal") can only predictably control 25 MOA up and 20 MOA down! (Those are very common numbers by the way.) Hope this helps! |
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