Missing elevation adjustment on a Savage 12LRP

Discussion in 'Rifles, Bullets, Barrels & Ballistics' started by freeflight, Mar 5, 2013.

  1. freeflight

    freeflight Active Member

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    Hi there,

    I put a Vortex PST 6-24X on my Savage 12 LRP in 260 REM. My setup is Weaver 20 MOA rail and Burris Signature Zee rings. Using the plastic insert, the rings provide 17 MOA. Together they should provide 37MOA, or 10.7 MIL of elevation gain. My sample of PST 6-24 has 20MIL of elevation adjustment. I thought I would have close to 20MIL of elevation adjustment.

    To my dismay, the scope only has 9 MIL of elevation adjustment after sighting in at 100 yard. In other words, 11 MIL was missing! I checked the plastic insert twice to make sure I have the correct setup: -10 on bottom of front ring and +10 on top, +10 on bottom of rear ring and -10 on top. I also measured the Weaver rail with caliper and it is 20 MOA. Similar rail and ring setup on my 111LRH provided 6 MIL of elevation gain, missing 4 MIL. I can live with missing 4 MIL, but 11 MIL are too much.

    Is this a problem with gun? Perhaps massive barrel drooping, or receiver top is out of spec?

    I am pretty sure I want to stay with Burris Sig Zee rings. Should I try another rail say Warne 20 MOA?

    Thanks for your input.

    Kevin
     
    Last edited: Mar 5, 2013
  2. Engineering101

    Engineering101 Well-Known Member

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    freeflight

    If I understand, you are saying that with the rail and Signature rings you were biasing your scope so you had very little down adjustment left and almost the whole range of up adjustment which of course would let you shoot as far as the scope can shoot but for some reason you ended up in the middle of the scopes range almost as if you had used no rail or inserts.

    If so, that is strange indeed. I have the Warne 20 MOA rail and Signature rings on the same rifle and it all worked as it should for me. If you have measured your rail changing to the Warne isn't going to fix anything and I doubt the rifle is to blame. Is the scope known good?
     

  3. Engineering101

    Engineering101 Well-Known Member

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    freeflight

    I just had one other thought. This is probably not the issue but since you use the Signature rings, I’ll mention it. I’ve noticed that a scope under recoil can slide in the plastic inserts on the Signature rings. I solved that problem by putting a piece of double stick golf club grip tape on the top of the scope under the plastic inserts. I love the Signature rings and have them on everything but you have to use the tape.
     
  4. freeflight

    freeflight Active Member

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    Hi Engineering101,
    You understand me correctly. I was counting on the elevation gain of 20 MOA rail and Sig Zee insert to shoot as far as I can. But still ended up in the middle of the scope.
    The scope is supposed to be good, no tracking issue. I had it on my AR with a 20MOA raiser, and gain about 5 MIL.

    I can only measure the thickness along the edge of the rail and calculate the cant. My guess is either the rail is out of spec, or the barrel wasn't installed squarely on the receiver (barrel drooping).

    I hope receiver top isn't out of spec. Main reason I bought the 12LRP is to reuse that Savage target action.

    Kevin
     
  5. freeflight

    freeflight Active Member

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    My experience with Sig Zee plastic inserts has been positive. I always remove oil from the inserts and rings before install them. I have them on my heavy barrel 308 (total weight 12 lb), and 7mm Rem Mag with a muzzle brake. Neither had any issue of scope sliding under recoil.
     
  6. Engineering101

    Engineering101 Well-Known Member

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    freeflight

    If you take the rail off and put some generic steel bases on the rifle and put the zero inserts back in the Signature rings you should find out if the problem is the rifle or the stuff you are putting on it.

     
  7. freeflight

    freeflight Active Member

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    Hi Engineering101,

    I am going to try a Warne 20 MOA rail and/or Burris Extreme rings to dissect the problem.

    If it is a problem with the rifle, I wonder how Savage handle this kind of problem. The gun shoots great, 5 shots of NCC 140gr groups around 0.5MOA. Still working on a load for Amax 140gr.

    Kevin
     
  8. Engineering101

    Engineering101 Well-Known Member

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    freeflight

    My 140 gr AMAX load is 41.4 gr of H4350. Runs about 2,700 fps and I’m guessing about 56,000 psi.
     
  9. freeflight

    freeflight Active Member

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    Thanks. I knew H4350 is the go to power, but all I have is H4831SC. My current load is Amax 140gr 0.01" off the land, 46.8gr H4831SC, 210M, 2833 FPS. 5 shots group are about 0.56-0.66MOA. Not bad, just not as tight as NCC 140gr.

    What bothers me is 3 shots around 0.2MOA, then next two shots open the groups up to 0.6MOA, there is definitely room for improvement.
     
  10. SoCal326

    SoCal326 New Member

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    Freeflight,
    Any chance you ever got this issue figured out?
    I've got a Savage 12 LRP in 6.5 Creedmoor with a Vortex Viper PST FFP 6-24X50 with EGW 20 MOA base and Burris XTR rings and only have about 7 Mil of elevation left. I would expect about 16 Mil (in a perfect world) but I should definitely have more than 7.
     
  11. SoCal326

    SoCal326 New Member

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    Looks like I won't be getting any response but I'll try to keep the thread alive for those with the same issue. I've seen this issue come up on other boards with the same setup so I'm sure it will help others if I get my issue figured out.

    I removed the scope and base. reinstalled and took back out to the range to confirm that there wasn't a mounting issue but the issue remained.

    Next step would be to buy a custom 45MOA base from EGW and call it a day or send it back to Savage to confirm that action and barrel are square.

    I decided to send it back. Savage was kind enough to send me a UPS shipping label and I'll get it in the mail in the next few days. Hopefully I'll have it back in about 5 weeks so I can Identify or exclude the rifle as the cause of the issue.
     
  12. Too Tall Rosenwald

    Too Tall Rosenwald Well-Known Member

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    Why not crank the scope all the way down and shoot, crank it all the way up, and measure the distance between them first. That way you eliminate the scope before you dismantle.