Problem with MOA

[Mike 243]

When you say the other rifles have the same setup just different barrel, are you screwing other barrels onto this action ? Or they are a separate action/scope set up the same ?

If it's one action and scope with a different barrel, it could just have a big bow in it like the others have said and when this barrel is on you're going to have to offset the bushings in the rings.

Otherwise.....




The thing to remember about this, is from a centered reticle, you have half that down. Which is just a little less than what you need for 1k *if* your scope was centered at 1k.

If you're 7" high at 300 bottomed out. Then you're ~5 minutes high from 100.

Your come up to 1k from bottomed out is probably around 18 minutes ? Is that about where you are when you're on target at 1k?

Either way, if you have the rifle/ scope sighted in at 1k I bet you can adjust the elevation approximately 52-18= 34 minutes higher before it stops.

If the bushings are correct, you may need to try a 10moa base instead of a 20 for this barrel. Theres always a chance you got a 30 moa base. You could compare measurements to your others.

EDIT: Fixed a few things. I outsmarted myself a few times.

Mike,
All 3 rifles are complete rifles no barrel changing. All 3 are built on Remington LA. Identical bases and rings. Gunsmith is going to check the bore it see if it is straight or if it has a bow and if it happens to be clocked up.

 

[Mike 243]

When you say the other rifles have the same setup just different barrel, are you screwing other barrels onto this action ? Or they are a separate action/scope set up the same ?

If it's one action and scope with a different barrel, it could just have a big bow in it like the others have said and when this barrel is on you're going to have to offset the bushings in the rings.

Otherwise.....




The thing to remember about this, is from a centered reticle, you have half that down. Which is just a little less than what you need for 1k *if* your scope was centered at 1k.

If you're 7" high at 300 bottomed out. Then you're ~5 minutes high from 100.

Your come up to 1k from bottomed out is probably around 18 minutes ? Is that about where you are when you're on target at 1k?

Either way, if you have the rifle/ scope sighted in at 1k I bet you can adjust the elevation approximately 52-18= 34 minutes higher before it stops.

If the bushings are correct, you may need to try a 10moa base instead of a 20 for this barrel. Theres always a chance you got a 30 moa base. You could compare measurements to your others.

EDIT: Fixed a few things. I outsmarted myself a few times.

Mike,
All 3 are complete rifles. All built on trued Remington LA. Same bases and rings. Gunsmith is going check bore for a bow and if there is where it is clocked at.

 

[ED3]

No

Could you explain what is changing? What is causing the divergence in the POA and POI if the relationship between the scope and receiver is not effected by the 'adjustment'? i could accept that interfering with the receiver's mount with the paper is introducing a vibration, or harmonic that did not previously exist, but that has nothing to do with the action not being parallel to the stock.

 

[Lone Hunter]

To me it would be like shimming a scope. Same principle but I don't think paper will last very long in the action.

 

[mac86951]

Ok, just gotta ask: .any chance your 20MOA rail is installed backwards?

-Mac

 

[MattPeetz]

Deleted

 

[ED3]

To me it would be like shimming a scope. Same principle but I don't think paper will last very long in the action.

Shimming between the scope and receiver changes the angle of the scope as it attaches to the receiver. Shimming between the receiver and stock does not change the relationship between the scope and receiver, unless the receiver is being distorted in some way.

 

[mikeeg02]

Mike,
All 3 rifles are complete rifles no barrel changing. All 3 are built on Remington LA. Identical bases and rings. Gunsmith is going to check the bore it see if it is straight or if it has a bow and if it happens to be clocked up.

You shouldn't need to take it to a gunsmith. But since you have the rings that have the inserts, put +10 in the bottom of the front ring and 0s in the rear ring. If that doesn't get you there, you may need to do +10 in the bottom of the front ring and -whatever you have left in the bottom of the rear ring. For all intensive purposes, that scope could also be a little "funny". If you want, since you have identical components you can swap one from the other and shoot and see which is different, but you can even easier just shim this scope to fit where it needs to be. Since you already have the rings and inserts to shim them that way.

 

[mikeeg02]

Ok, just gotta ask: .any chance your 20MOA rail is installed backwards?

-Mac

If the case was on backwards, he wouldn't be able to get enough come up to 1k. He would have the opposite problem. I fought with myself a few times and edited my first post becuse I included that option, forgetting "come up" is actually moving the reticle down.

 

[Mike 243]

Ok, just gotta ask: .any chance your 20MOA rail is installed backwards?

-Mac

Mac,
How could the base be on backwards. Front and back mounting holes differ in spacing. Base is predrilled.

 

[Mike 243]

Ok here's the findings. The trued face of the Remington action by a gunsmith is actually out by 7/1000" on the bottom of the face. In turn when everything is locked together has the barrel running uphill. Multiple the 7/1000" by a 28" barrel and you have a lot over the barrel length. Fix is to take the -20MOA base off and in stall a 0 MOA base. When a new barrel is installed at the end of the season the action face will be trued by the gunsmith that found this action not to be trued by a different gunsmith.

 

[mikeeg02]

Can you see a gap anywhere between the shoulder and the action?

You'll have to have a light on the other side, and try to look across the seem where the action and barrel meet. And rotate it so you can see if there is any gap anywhere around the circumference. If there isnt any gap, then its shouldering up properly. If the person who first "trued" up the action touched up the threads, and made it a so the threads and action face are perpendicular to each other, I would be hesitant to have someone else do the same, and remove even more material on a factory action.

If you can see a gap at any point, I wouldnt waste much time shooting that action anymore until the barrel is properly shouldered up. You will learn very quickly about inconsistencies that show up on paper you cannot tune out.

If there is no gap, just swap the base, or offset it in the rings and go shoot and be happy.

Hope that helps.

 

[Mike 243]

We put a little film of grease on the action face. Assembled the recoil lug and barrel then took it back apart and there was a section that the grease didnt push out.