Need Advice... Is it my scope, the mounts or barrel?

The #1 community for Gun Owners of the Northeast

Member Benefits:

  • No ad networks!
  • Discuss all aspects of firearm ownership
  • Discuss anti-gun legislation
  • Buy, sell, and trade in the classified section
  • Chat with Local gun shops, ranges, trainers & other businesses
  • Discover free outdoor shooting areas
  • View up to date on firearm-related events
  • Share photos & video with other members
  • ...and so much more!
  • Doitsouthstyle

    Active Member
    Apr 4, 2012
    981
    Baltimore County
    This now the second time shooting this AR with the same results. It's a 24" Anderson complete upper with a Nikon P-223 4-12x40 with P-series mounts. Start sight in at 25 yards and was close enough to center to jump out a 100 yards. And again point of impact is 30+ inches about point of aim and that's after turning elevation all the way up. Last time I took the scope off and sent back to Nikon for Service got it back with no explanation of what they did.
    1st picture 25 yards
    2nd picture 100 yard set up
    3rd is point of aim which was about 8-10" below blue target.
    4th is my point of impact
    I apologize for side ways picture
    What are your guys thoughts on my issue? I should have took the mounts and scope of one of my hunting rifle was was expecting this to happen again. Probably going to be my next move just hate to remove a scope off a gun that is already sighted in but may have to bite the bullet. Cheaper then buying another scope and mount set up to just resight in my 7mm.
     

    Attachments

    • IMG_4311.jpg
      IMG_4311.jpg
      51.5 KB · Views: 242
    • IMG_4312.jpg
      IMG_4312.jpg
      137.2 KB · Views: 235
    • IMG_4313.jpg
      IMG_4313.jpg
      124.4 KB · Views: 247
    • IMG_4314.jpg
      IMG_4314.jpg
      47.1 KB · Views: 240

    Doitsouthstyle

    Active Member
    Apr 4, 2012
    981
    Baltimore County
    A few pictures of the gun giving me problems.
     

    Attachments

    • IMG_4317.jpg
      IMG_4317.jpg
      92.5 KB · Views: 222
    • IMG_4318.jpg
      IMG_4318.jpg
      94.2 KB · Views: 229
    • IMG_4319.jpg
      IMG_4319.jpg
      103.7 KB · Views: 226
    • IMG_4321.jpg
      IMG_4321.jpg
      85.5 KB · Views: 221

    dist1646

    Ultimate Member
    May 1, 2012
    8,758
    Eldersburg
    Presuming the 25 yd target is oriented vertically with the writing at 12 O'clock, if you turned the elevation up, you went the wrong way. If the group is high at 25, it would place the group even higher at 100. The height of the scope above the bore will add to that difference.
     

    sgt23preston

    USMC LLA. NRA Life Member
    May 19, 2011
    3,994
    Perry Hall
    A couple of quick questions:

    #1. Are you shooting off of a bag or bi-pods..?

    #2. What ammo are you shooting = bullet weight & load..?

    What I would do is this:

    A. Go back to 25 yards & ZERO the scope so that every round is dead on...

    Shoot it off a sand bag or bi-pods...

    Try to make PERFECT shots = squeeze the trigger...

    IF it is shooting high move the scope - DOWN or + UP if it is shooting LOW

    Keep adjusting until all the shots are dead on...

    B. Try it at 50 yards, expect the point of impact to be higher, RE-ZERO the scope at 50 yards...

    C. Move to 100 yards & RE-ZERO again...

    In my experience, at this point the scope should be very close from 100 to 25 yards with GOOD Quality 55 grain factory ammo...

    Leave the scope set on the 100 yard setting...
     

    Doitsouthstyle

    Active Member
    Apr 4, 2012
    981
    Baltimore County
    No last time is was a little freedom my dad had brought and then switched to red box federal bulk. All has been 55 grain wasn't expecting to shoot perfect groups but get the scope dialed in a close then work a really good hand load
     

    dist1646

    Ultimate Member
    May 1, 2012
    8,758
    Eldersburg
    Yes but at 100 yards I should have been 3-4" or so high and I was no where near on my paper or my targets backing.

    Looking at the group on 25yd target, with a normal scope height of 1 1/2" above centerline of the bore, you should have been around 4" or slightly more at 100yds. The Scope looks to be higher than 1 1/2" above the bore to me and that changes the angular projection ratio, thus causing the shot group to be higher. There may also be a slight difference in the height of the "P" series mounts, since they are separate and therefore not line bored, that could be increasing the difference you are seeing. You could try switching the position of the mounts, so that the one in the front is in the back, to see if there is as much of a change in elevation from 25 to 100. If there is a difference in the height of the mounts, this should reveal it.
     

    Doitsouthstyle

    Active Member
    Apr 4, 2012
    981
    Baltimore County
    That is a great point I will take me caliper as well and see if there is a difference in height before full removal from bottom of ring to top of upper. I am going double check bore axis versus center of scope. And sorry from previous post I was shooting off a front bag elevated with a shipping blanket fold under it to help muzzle and butstock height no rear bag.
     

    Magnumite

    Ultimate Member
    Dec 17, 2007
    6,561
    Harford County, Maryland
    The 25 yard zero is throwing your shots high - think mortar fire here. The scope line of sight is 2 5/8"'over bore centerline. A fifty yard zero would be approximately 1 1/4" below POA at 25 yards. A 100 yard zero would be about 1 7/8" low at 25 yards. These numbers are close approximations. The farther apart line of sight and bore centerline get the more pronounced this phenomenon gets.

    As a previous poster also indicated for high impacts the elevation adjustment gets moved down.
     

    TheBulge

    Active Member
    Mar 7, 2011
    344
    Where was the point of impact at 100ydr before you turned the elevation all the way up?

    It should have been about 5 or 6" high depending.

    Assuming your scope mount is not loose I think you are dialing the wrong direction.

    Nikons says you have 60moa total adjustment. So 30" in either direction at 100yrds is about right for maxing it out. You just went the wrong way.



    .
     

    Doitsouthstyle

    Active Member
    Apr 4, 2012
    981
    Baltimore County
    2-5/8 " seems correct just tried to caliper it and was wrong in assuming up was up in point of aim not point of impact. As far original before adjusting i had two targets side by side so if you look at picture 2 if I was aiming a center 54" from ground ENSRO was admit about I was hitting 19" high now that I have my tape measure and not rushed which is about 19"+/- which with 2-5/8 and Nikon spot on should be about 6.44"
     

    Doco Overboard

    Ultimate Member
    I would shoot the rifle at any distance I could get paper. Then I would count the clicks to bottom the turret and then return to original setting, fire the rifle again to make sure the adjustments to the turret have been proven to be repeatable. If this is found to be the case I would then bottom the turret, then raise and then center the reticle by dividing by two and then bore-sight/ zero the rifle again to establish reputability. When a scope is right and you are shooting good you should be able to adjust the device to all four corners of a gridded sight in target with relative ease at 100 yds. if it has 1/4 clicks (the Scope)
     

    Biggfoot44

    Ultimate Member
    Aug 2, 2009
    32,877
    I would remove the upper and BCG and do an old school eyeball boresighting, but that is a thread in itself.
     

    outrider58

    Eats Bacon Raw
    MDS Supporter
    Jul 29, 2014
    49,810
    I'm confused. If you are hitting high at 100yds., why are you dialing your scope up? You are going in the wrong direction.
     

    davsco

    Ultimate Member
    Oct 21, 2010
    8,607
    Loudoun, VA
    get a nice tight group at 25 yards and set your reticle for that and shoot it again and confirm. then go to 50 and you should have a nice tight group within let's say 2 inches of vertical. then go to 100 and you should have a nice tight group within a few inches of vertical. if all that works, THEN adjust your scope up or down as needed so the reticle is dead on at 100. you want everything very consistent here. same front and rear rest, same ammo, same everything. make sure your actual barrel isn't resting on anything, only the forearm.

    if you aren't getting a nice tight group at 25 (should easily be within an inch), reconfirm your scope is mounted tight and nothing is loose. make sure you are really taking your time with pulling the trigger, not one huge yank.
     

    Users who are viewing this thread

    Latest posts

    Forum statistics

    Threads
    274,915
    Messages
    7,258,441
    Members
    33,348
    Latest member
    Eric_Hehl

    Latest threads

    Top Bottom