Skip to main content
Help Center Community Shop

M1D Scope Mounting - Shooting Low - Report

Don McManus
Took the M1D out today to sight it in. Not good.

At the end of the elevation adjustment and it is shooting around 12" low at 100 yards. Grouping quite well, and repeats after removing and remounting the scope. Reset both the scope in the tube clamp and then the entire mount. Both times ended up grouping within a couple of inches of original group.

Good three-point contact on the base, top front, top back and the wedge beneath the block, and there appears to be no deformation in any of the pieces, and the tube clamp appears to be in good shape and fits consistently snug around the scope tube.

I am hesitant to shim inside the tube clamp, as that would create uneven pressure around the tube. I can file a bit off the front pad on the mount and ship an equal amount under the back pad, but am hesitant to alter the mount.

Any advise would be much appreciated.
0

Comments

6 comments

Date Votes
  • nmyers
    You can get additional adjustment on the M84 by partially unscrewing the outer retention nut on the elevation turret. The inner adjustment screw can then be turned pass the detent. In order to unscrew it, you need to make a spanner screwdriver from a large screwdriver by grinding out the center section, then hollow grinding the 2 sections that fit in the slots on the outer nut.

    Hopefully, this will make sense to you once you are looking at the scope.

    Neal

    EDIT: Supposed to get up to 3 full turns in either direction with this method. Of course, you don't how much it was moved by a previous owner. Note sure what you are describing about the inner nut.
    0
  • Don McManus
    Thank you, Neal, it does make sense.

    I loosened the outer screw, but he inner screw (on both turrets) has a small center post that prevents engaging the slots. I'll try to make a second spanner for it today, though it is so small, I am not sure about the effectiveness of the smaller spanner.

    It looks like I need to gain at least a quarter turn on the elevation turret. Do you know if there is a quarter turn of additional adjustment available using this technique?

    Thanks again,

    Don

    EDIT Great news, Neal, thanks yet again.
    0
  • 5mmgunguy
    Any way to use Burris mounts that take the plastic inserts. You can get inserts with +- 20 degrees. Using two of them you can get 40 MOA at 100 yards. And they put no stress on the tube.
    0
  • Don McManus
    Neal, I cannot thank you enough.

    What you suggested is nothing that I would have thought of, nor did I find anywhere else.

    Many, many thanks.

    Don

    BTT - Thanks again, Neal.
    0
  • nmyers
    Glad to be able to help. It's nice to have a satisfied customer occasionally.

    Neal
    0
  • Don McManus
    Put 30 rounds through it yesterday, mixed results.

    Scope now can be properly sighted, though the best I could do was 4" goups.

    It was fairly cold (25?) and shooting 5-shot groups at 100 yds. First group got me into the target area of the paper.

    Second group was used to set the windage.

    Third group was used to set elevation.

    Final three groups were fired with no changes to the turrets, and were interesting:

    First round was 3 - 4 inches low. Second a bit higher, third higher yet, 4th and 5th on point of aim. Was getting 1.5" (probably me) on last two shots on the last 3 groups, with the earlier ones all stringing as noted.

    Have not seen this before, so I'll wait till warmer weather before I get too worked up about the stringing (unless someone knows what is going on).

    Just wanted to post a quick range report. Thanks again to all.

    Don
    0

Please sign in to leave a comment.

Recent Activity