Shooting 24" to the right

fiftycalforsquirrels

fiftycalforsquirrels

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The rifle in question is a Savage model 12 with an aftermarket barrel that shoots 24" to the right at 100 yards with the windage turret at mechanical zero.

When I first got the rifle, it had a steel 20 moa base on it. I mounted a bushnell 4200 on it with a set of Burris Signature Zee rings with 0/0 inserts. The rifle shot 2 minutes to the right with a mechanical zero on the scope....close enough.

Then I decided to put my Sightron SIII on. In doing so, I changed the scope rail to a 30MOA MDT rail and Burris Signature XTR rings. 0/5 on the insert. Mechanical zero on the scope. Bang.... 24" to the right. Put a 20moa shift to the left insert in there, bang... within 1/2 minute on the windage.

Normal scope mounting procedure for me is to put the rifle in the bags so the stock sits square to the bags and then plumb bob the reticle square.

I did note that the mdt rail is bowed out of the box and rocks on the action. (2 different 30moa MDT rails, exact same bow and rock) but when torqued down the rail is flat.

What gives? Guess process of elimination of swapping the rings front to back(or 180°), changing rail, changing rings, changing scope... blah. Could just leave it with the 20 insert cause it's bang on now...but I lose sleep over stuff like this especially knowing a previous ring rail scope set up within 2 minutes on the windage.
 
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Yes... if it goes straight on the windage line at some distance that will be real sweet. You're probably right.... not all created equal... I just cant help but think something is wrong....even though its basically fixed with the inserts.
 
Given the use of CNC machines when manufacturing receivers and barrels, it would be reasonable to assume that with late manufacture firearms, bases, rings, and scopes, a person should be able to swap scopes from one rifle to another without having to change windage or elevation, as long as the loads are equal.

That just isn't the case.

There's a very good reason bases have generous clearance around the screw holes and tapers for the screw heads to pull them to center.
 
tiriaq said:
Two rails bowed - or is it the receiver?
Click to expand...

I wondered that... but I think its the rail(s). The steel rail I took off doesnt rock on the action. When I put the steel rail and the MDT rail ontop of each other(top surface to top surface) the MDT is bowed compared to the steel one. When I torque the MDT rail down and then place the steel rail on it top side to top side, the MDT is flat

The 2nd MDT rail wasnt checked on my action. It was a separate Savage model 12. Same rock on the action, same bow compared to the steel rail, and going flat when torqued down.

The steel rail didnt rock on either model 12 action.

Not exactly scientific and could get more precise... but it's close enough for me to determine that the rail isnt neutrally straight and flat.
 
Bore sighting would save some grief. Even before you cinch everything down and then after. Center the reticle first like you do is always a good idea. If you have done that one thing that really helps is to put a vertical line one a wall behind the scope a few feet then from the front line up the bore with the vertical line and then see how far out the reticle windage is. It’s also a good way to tell if your scope is level. A lead sled is great for this process. Also looking through the scope from the front with the bore directly below the scope front objective the reticle should be in the center of the scope if your mounts and rings are perfect. If you have to move your head away from the bore to center the reticle that means your scope is crooked and not parallel to the bore or centred longitudinally.
 
Perhaps I’m off base but I assume that switching to a 30 MOA base from a 20 suggests you intend or are shooting at extreme distances.
If that is so then I’d be concerned that your correction has regulated your zero to a given distance. I’m no long range shooter but if the scope is offset from the bore then an I would assume the bullet path converges as it flys towards the zero and diverges from it afterwards which at great distance is likely a bad thing…I assume, I could be wrong on the whole theory of it but that is what my thinking would be.
If you use the same offset inserts front and rear orientated in the same plane the you are moving the scope over inline with the bore, if you have different inserts you put the scope at an angle to the bore. Normal ranges likely negligible differences but somewhere out there it’s likely measurable.
Why not use the known 20 MOA base and use inserts to get the other 10?
Also, I’d find a known straight edge because scope rails are not meant to be warped and then pulled true (to my knowledge).
To add did you try the original scope on the new rail and try that, perhaps your scope is contributing (?)
 
Melvin said:
Bore sighting would save some grief. Even before you cinch everything down and then after. Center the reticle first like you do is always a good idea. If you have done that one thing that really helps is to put a vertical line one a wall behind the scope a few feet then from the front line up the bore with the vertical line and then see how far out the reticle windage is. It’s also a good way to tell if your scope is level. A lead sled is great for this process. Also looking through the scope from the front with the bore directly below the scope front objective the reticle should be in the center of the scope if your mounts and rings are perfect. If you have to move your head away from the bore to center the reticle that means your scope is crooked and not parallel to the bore or centred longitudinally.
Click to expand...

I plan on revisiting my scope mounting practices to include the method you describe of putting a plumb line on the wall then lining it up backwards through the objective and/or bore. I agree that using this technique can quickly rule out errors rather than tightening everything down and firing the rifle. I will likely use this approach going forward.

wasrupzuk said:
Perhaps I’m off base but I assume that switching to a 30 MOA base from a 20 suggests you intend or are shooting at extreme distances.
If that is so then I’d be concerned that your correction has regulated your zero to a given distance. I’m no long range shooter but if the scope is offset from the bore then an I would assume the bullet path converges as it flys towards the zero and diverges from it afterwards which at great distance is likely a bad thing…I assume, I could be wrong on the whole theory of it but that is what my thinking would be.
If you use the same offset inserts front and rear orientated in the same plane the you are moving the scope over inline with the bore, if you have different inserts you put the scope at an angle to the bore. Normal ranges likely negligible differences but somewhere out there it’s likely measurable.
Why not use the known 20 MOA base and use inserts to get the other 10?
Also, I’d find a known straight edge because scope rails are not meant to be warped and then pulled true (to my knowledge).
To add did you try the original scope on the new rail and try that, perhaps your scope is contributing (?)
Click to expand...

You're not far off... I plan to try and poke out there. It's just a 223 shooting heavys but... still a 1000 yard caliber according to F class.

I *could* get there with the 20moa base, and I planned on buying a 20moa MDT but it was out of stock so I picked up the 30 thinking if it was too much I could dial it out with the inserts...but 223 does need quite a bit of elevation to get out to 1k so I ran with it. Either 20 or 30 will work, especially since I am using insert rings. My reason for changing the base was thinking the MDT rail would be better/an upgrade because the steel rail I have is unmarked, unknown brand. But... chances are this steel rail is of better quality and it very well might find its way back onto the rifle. It could be the rings...or the scope....all 3 things got changed at once.

The bullet converging then dispersing theory is how I think about it as well, also not sure if thats a correct line of thought. I planned to atleast do some elevation knob twisting and firing before getting carried away on changing anything again.

What my end goal is(and I'm sure a lot of peoples goal is) is to have the elevation knob introduce zero windage error and not have to "walk the bullet in" ever. I want to know my windage is zero at any given time, and any deviation is infact the wind.
 
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fiftycalforsquirrels said:
I'm having trouble with what you mean...

As in the Horse Barn would take it up with MDT?

Or go to the horse and buy some different stuff
And
Talk to mdt on my own time
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sorry, old guy talk
the best story comes direct from the horses mouth, 'go to the horses mouth '
in this case, if it is a MDT piece, they would have the best info


though the Horse Barn is a good, little known store to shop at ;)
 
I do 'mech zero' then use bubble levels while the rifle is in my vise. Then a laser bore-sighter at 25-yds. Gets me pretty close on paper at 50. That's what the turrets are for.
 
Most folks don't have this option, but I set up a target at 25 yds.

The target is made from an old wire political campaign sign frame we see in people's yards and alongside the well travelled routes just before elections. I use these for "bore sighting."

Our local NDP candidate lost, and none of their "volunteers" bothered to pick up the campaign signs. I left them alone for over a month, then picked up as many as I could find, gave the generic frames to a Conservative candidate, and kept a half dozen for myself, along with all of the plastic presentation sleeves that fit snugly over them.

I turn the sleeves inside out because they're always painted on the outside, but white on the inside.

I use a strip of 1 inch wide black tape, appx 1ft long, for the vertical bar and an indentical strip for the center horizontal cross bar.

I use a red strip of tape, appx 1/2 inch wide and appx 8 inches long, 1/2 inch above the center horizontal bar as 200 yd zero.

This system is great as it's very mobile, and it can be taken into the field very easily as well.

The wire frames are extremely tough. They are made to be stuck into the ground, sometimes almost rock hard, slip a "sail" over, and stand up to 75km winds without bending. The plastic sleeves will withstand hundreds of shots, and you can use either tape or pins to attach paper targets.

The vynil plastic is even recyclable, as are the paper targets. win win.

If you can do it, this system will usually get you onto an 8x10 paper target at 100yds, unless something is wrong.
 
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