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  #1  
Old 11-12-2018, 09:20 AM
bjor13 bjor13 is offline
 
Join Date: Sep 2018
Location: Northern KY
Posts: 90
Default need some M84 scope advice

took my 1903A4 with m84 scope to the range this weekend. at 25 yards I was about 6 inches low and to the left with the elevation and windage knobs maxed out. At 100 yard I was 4 feet low and wide.

I have read that I can loosen the knobs and work on aligning the reticle or I can shim the front and adjust the rear mount screws to bring it into the proper windage alignment. I am not sure which way to go. Any thoughts? Also anyone know how I can find the true middle of the windage and elevation adjustments and start from there?

Thanks in advance!

found this on the internet for m84 adjustment

The M84 telescope is equipped with a post and cross-hair reticle that may confuse the shooter previously experienced with cross-hair reticles only. As some have discovered, the heavy post subtends about 3 m.o.a. and obscures a significant portion of the target if it's intersection with the cross-hair is used as the aiming point. Also, the cross-hair appears about 12 m.o.a. lower than mechanical/optical axis of the telescope, possibly causing some rifles to shoot abnormally high at short range. In short, use the top of the post as the aiming point as you do with the iron sights.

This procedure is used to adjust the mechanical limits of the windage and elevation knobs, and to mechanically zero their respective scales to the rifle on which the scope is mounted. The windage and elevation knobs are held in place by the larger of the two round nuts in the center of each knob. The larger nut secures the knob to the detent, which in turn is secured to the knob shaft. The small inner nut prevents the larger nut from backing off the shaft when making adjustments to the knobs. The round nuts can be turned with a flathead screwdriver with clearance ground out to clear the small inner nut.

First hold the knob in place and unscrew the larger nut about 2.5 turns or until it is stopped buy the small inner nut. You can now disengage the knob from the detent/shaft and turn the knob independently of the shaft. The detent/shaft is capable of approximately 720* of rotation while the knob is limited to about 350* when secured to the detent.

If you could not previously zero the rifle because one or both knobs had reached their mechanical limit, you can now adjust these limits. When the knob is at it's limit, lift the knob to disengage the detent/shaft and rotate the knob X* opposite the direction in which you reached the limit. Lower the knob to engage the detent/shaft at this new point. You have now moved the mechanical limit X* past the point of the previous limit thereby allowing further adjustment in that direction. You should again try to zero the rifle and repeat this adjustment as required, remembering the rotation of the shaft/detent is limited to 720*. After the rifle is zeroed, mechanically zero the scales on the knobs as explained below.

If the rifle was previously zeroed, and you haven't moved the knobs, you only need to lift the knob to disengage the detent/shaft; rotate the knob independently of the detent/shaft until the correct point on the scale is aligned with the pointer; lower the knob to engage the detent/shaft and tighten the larger nut. Do the same to the other knob and your done and you are finished.
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  #2  
Old 11-12-2018, 09:36 AM
bigwagon bigwagon is offline
 
Join Date: Mar 2018
Location: Milwaukee, WI
Posts: 236
Default

I don't know anything about the specifics of the internal windage and elevation adjustments on the M84 scope, but you are correct that once you have them in the center of their range, you can make gross mechanical windage and elevation adjustments by shimming the mount and using the rear mounting screws.
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  #3  
Old 11-12-2018, 10:07 AM
ceresco ceresco is offline
 
Join Date: Oct 2009
Posts: 7,587
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Shim the back of the base. Folded strips from an aluminum beverage can..... Good Shooting. ..
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  #4  
Old 11-12-2018, 02:56 PM
chuckindenver chuckindenver is offline
 
Join Date: Jan 2012
Posts: 2,704
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center your left and right in the scope, then use the windage knobs on the base to bore sight, shimming the front of the base will make it shoot lower. shimming the rear will make it shoot higher
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