Reply With QuoteJust a thought but rotate them 180 degrees to see if it effects the vertical adjustment in the direction you want.
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 has only 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
Just a thought but rotate them 180 degrees to see if it effects the vertical adjustment in the direction you want.
Its been my experience that you cant count on the full gain of a 20moa rail and rings.
I added a 20moa rail, and only gained about 10moa.
Im 8.6 mil to 1k, if I run out of adjustment, I use the reticle. My bushnell gets me 11ish mil. Before topping out.
I run a 6.5cm LRP, EGW 20moa, seekins rings and Bushnell 6-24x50 with G2DMR reticle.
Sent from my GT-N8013 using Tapatalk HD
I tried to swap front and back rings, didn't make any difference. I could try to rotate the plastic insert 180 degree. Thanks for your suggestion.Originally Posted by stangfish
Last edited by freeflight; 03-07-2013 at 01:02 AM.
I understand what you're saying. I am okay with losing 10MOA or 4 MIL, but 11 MIL is too much. There is definitely a problem with scope mounting or the gun itself.
The main reason I want to figure this out is to make sure it is not a problem with the receiver. I plan to reuse that Savage Target Action in the future.
If the scope itself has 20MIL of adjustment, then I would expect 10MIL of travel, minimum, remaining in your elevation from a level (0 MOA) mount zeroed at 100yds. The wedge of the rail, the inserts, should all combine to increase your remaining travel from there. That's the purpose of the wedge, and if you have less than half of the scope's range of travel at point blank ranges, then something is wrong. Any chance you're measuring the remaining adjustment in the wrong direction?
It's either the scope or it's your math. I've never done this myself, but here are a couple of things I would do to sanity check the rig: I expect the rail should raise the eyepiece and lower the objective. Is that what you're seeing? What about the inserts -- is that what they do, too? Also, if you have the option of adjusting the ring spacing, then closer spacing will get you more gain, much like a shorter wheelbase makes a jeep pitch more on speed bumps.
If you've got the windage centered, you might want to roll the scope 90 degrees and then adjust your elevation knob to center the vertical hair over the barrel. That'll give you an idea if the mechanical elevation center is anywhere near the optical elevation center. Maybe your scope's out of whack and it takes a bunch of MOA just to center the elevation knob?
I have done this kind of setup many times. The scope worked fine on my AR that has a 20 MOA raiser, it gained about 5 MIL in elevation. PST 6-24 has side parallax adjustment, can't be mounted when rotate 90 degrees. Thanks for your suggestion though.
The problem is either the mount or the gun. If it is the gun, then either massive barrel drooping or out of spec receiver.
Let's start over. I'm not suggesting a permanent mount. I'm saying that if you roll it 90 degrees you can use the barrel to determine how far the optical elevation center is from the mechanical center of the elevation adjustment. This would give you an idea of how much minimum travel you should expect before any gains from the incline. But then again, I don't assume the scope is good -- and I just automatically distrust the most delicate, most complicated, most difficult-to-eyeball component -- which is still the scope.
If it's the receiver or the barrel, you should be able to duplicate the problem with standard mounts, and preferably a different scope. Are both rings perpendicular to the rail? You're quite certain they're both seated correctly and identically on the rail? Any chance the rail itself is not flush against the receiver, or obstructed somehow?
It's hard to imagine an alignment problem so severe that it eats up all that gain without being visible some other way.
I realize you have a side parallax knob, but I have that on one of my scopes and I still have sufficient clearance to mount it sideways -- is that not the case with yours? And in retrospect, any discrepancy in the low tens of MOA is less than a degree, and thus may not be so easy to eyeball. Good luck.
Last edited by cpurick; 03-07-2013 at 10:49 AM.
Savage recievers are belt sanded to get that grainy finish and one way to check how flat the reciever is to take the rail off and make sure there are no burrs on the mounting surface,then you put the front screw in only,see if there is a gap at the back(light under rear of the rail,that tells you the reciever isnt flat and you must shim the back to get it to lay flat,then reverse the procedure and check to see if the front is hanging up in the air,shim it as necessary.I usually bed the rail if there is a gap by applying epoxy under the end that has a gap and only tighten the end lightly till it drys.You can put kiwi boot polish on the reciever and none on the rail,when it drys you can remove the rail easily if you have too. I have run into this on almost every reciever they make.It is easy to do and not worth sending back as the next one could be just as bad.
Willing to give back for what the sport has done for me!
I understand your suggestion. It is a good idea to inspect the scope. I have a Warne 20 MOA mount, a pair of Burris Extreme Tactical rings, and a spare scope. I will spend half a day at the range to get to the bottom of this.
I seat the rings by pushing them forward against the rail, they are perpendicular to the rail as far as I can tell. The rail appears to seat flush on top of the receiver.
Before I install the rail, I removed any oil or grease on top of the receiver. Don't remember seeing any burrs. I haven't bed any rail so far, but it is an option I could do.
The gun shoots great, 5 shots of NCC 140gr consistantly group about 0.5 MOA. That's why I am kind of reluctant to send the gun back. Who knows what will happen in the service dept.
Can we see a picture of your set-up? Does the rail overhang the bolt or the barrel nut? It should look like this...
Last edited by stangfish; 03-08-2013 at 07:43 AM.
Interesting to come across this... I have a 12 LRP in 6.5 CM, also currently wearing a Viper PST 6-24x SFP mil/mil scope. It's mounted on an EGW 20 moa 'F-Class' rail (the one with the long cantilever out front) using Warne Tactical rings. I hadn't really thought about how much 'up' I had available until some friends were shooting at some long range targets in prep for an upcoming field/tactical match. Longest one was @ 1350, and my ballistics app called for 14.7 mils of 'up' from my 100yd zero. I ran out @ ~12.4 mils, which was an unpleasant surprise. Guess I need to spend some time figuring where my 'lost' elevation went also...
Sure, it does overhang the barrel a little bit. The barrel nut steps down from the receiver. I hope this won't cause problem.
Here is the picture
Last edited by freeflight; 03-08-2013 at 11:08 PM.
You lost about 3 MIL, not too bad. You could try Burris Signature Zee rings to gain some elevation.
I've gotta ask if you ground off the recoil lug on the weaver base?
Yes I did.
I have the exact same setup as you and I get 15 mils and I am zeroed at 200 yards. Lrp in 260 with a 6x24x50 pst ffp weaver base and burris xtr rings.
I'm bumping an old thread because I'm having the same issue and there didn't seem to be a solution.
I have a savage 12 LRP in 6.5 Creedmoor, 20 MOA EGW base and Vortex Viper PST FFP 6-24x50. When I zeroed at 100 yards I only had 7 Mil of elevation left, which won't get me out to 1000 yards, I need 9.
The scope has 20.5 Mil of adjustment so I should get about 10.25 Mil up or down. When I add the 20 MOA base in (5.82 Mil) I should have about 16.12 Mil left.
16.12 - 7 = 9.12 Mil missing.
I'm going to try to shim the back but can only get one layer of a soda can under it, not even sure I need that though because the rail contacts pretty well. The wider portion of the rail is near the eye peace so that's good to go.
My other option would be buying a 40 MOA base which should give me 5.82 mil more than I have now for a total of 12.82 Mil up and about 7.68 down.
Any one know where to get a 40 MOAbase or even a 50?
A 20 m.o.a. base should have .035" difference in height from front to back. Something I just learned after checking some Burris Signature inserts... they are often mis-marked. I had several +10's that were the same thickness as -10's. Another thing, the numbers do not represent moa, it is the difference in thickness.(+-.010")
"As long as there's lead in the air....there's still hope.."
It sounds like the 20 MOA base is installed backwards.
"The truth is that all men having power ought to be mistrusted." - James Madison
It does sound like the rail was installed backwards but it looks just like the setup in poast #12. Complete with the Burris XTR rings. sharpshooter's comment has convinced me to spend more time inspecting my setup. .035" isn't much and if a few tolerances were off in the rail, rings and action it could add up fast. I'll inspect, reassemble and take back to the range to make sure it wasn't a small mounting issue on my side before I start replacing parts.
Elevation and Windage are not independent. Think of a circle within a slightly larger circle. As the inner circle moves towards the edge in the horizontal direction, the amount of room to move up and down becomes less and less. The erector that holds the reticle is basically a tube inside the main scope tube. If you're scope is cranked towards the limits of windage adjustment, that could be where the loss in elevation adjustment range is coming from.
Well, I remounted the scope with the same results, phenomenal accuracy but not enough elevation left. I'm going to buy a 40 MOA base and that should do the trick. I'm guessing the barrel and action aren't square but there is no way for me to know.
The 40 minit base will help the elevation but might well cause another issue, that being windage zero.
We had elevation issues with the same scope with my sons 338x378 and a 20 minit base and it isnt a
savage action. We did go to a 40 minit base which gave us more elevation but it wouldnt allow zeroing
the windage as all the remaing windage was all on one side. I swapped scopes to an 8x25 leupold and
found the same problem but in the opposite direction. Ive solved the windage issue by installing a set of
U S OPTICS windage adjustable rings. A bit salty as for cost but they solved the issue. Ive since shot this
gun at 1500 yds and there was enough elevation adjustment with the 40 min base. Im not sure by how much
however as i havent tried. Bottom line is that although these are nice scopes and especially when cost is considered,
they dont measure up when trying to shoot the longer distances. A 338x378 should be enough gun to bust rocks out to
a mile or even more. But guess what, he aint gonna do it with this scope.
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