Rifle Scopes Out of Elevation

[BlackWhiskey]

Let me preface this with saying that I am not new to scope mounting or bore sighting, nor am I new to the world of long range shooting. Please read the whole post before responding.

This morning I was helping a friend of mine mount his brand new Millett TRS-1 on his Howa 1500 on a 20moa base and Burris XTR rings. After leveling the rifle, I put the rings on and leveled the scope, and checked it to make sure by holding the reticle against a dead vertical stake.

We then preceded to bore sight the rife at 25 yds. After doing so I tested the remaining elevation and only got 6.2 mils. I know that the round will impact high (1.2 or so mils) at 100 yds with a 25 yd zero, but that still only leaves me 7.4 mills of elevation. So I took it out to 100 yds to bore sight and after making the adjustments I have only 7.2 mils of elevation remaining. Something seems wrong here as I am well above optical center for the scope with a 20 moa base and a bore sight at 100 yds. I know that an actual zero will vary quite a bit from the bore sight, but even then I would need to be around 6 mils off to get to where I predicted we'd be elevation wise.

Your respectful responses and suggestions would be appreciated.

Thank you,

Cory

 

[timelinex]

Re: Out of Elevation

First thing that comes to mind is base is on backwards

 

[BlackWhiskey]

Re: Out of Elevation

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: timelinex</div><div class="ubbcode-body">First thing that comes to mind is base is on backwards </div></div>

I thought that too, but it is on correctly.

 

[flyrodder]

Re: Out of Elevation

I have a TRS-1 on a 20 MOA base, and my situation is the opposite. I am essentially bottomed out, which makes for a poor man's zero stop, so I'm not complaining, but my experience with the TRS-1 indicates it may not be the most precisely designed and constructed optic on the planet. That may be your problem.

 

[BlackWhiskey]

Re: Out of Elevation

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: flyrodder</div><div class="ubbcode-body">it may not be the most precisely designed and constructed optic on the planet. That may be your problem. </div></div>

I think this is probably the case. I spoke with their CS and they said to send it in, so that's what I'm going to do.

 

[VKC]

Re: Out of Elevation

Hope you get the problem resolved.

 

[Rhys]

Re: Out of Elevation

What are the chances the base is not 20moa, and is in fact 0moa?

 

[9H_Cracka]

Re: Out of Elevation

I would actually fire a round with the rifle and see where it comes up rather than relying totally on one's bore sighting prowess in drawing such conclusions.

 

[JGorski]

Re: Out of Elevation

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Rhys</div><div class="ubbcode-body">What are the chances the base is not 20moa, and is in fact 0moa? </div></div>
Here's what a 20moa base looks like.

 

[BlackWhiskey]

Re: Out of Elevation

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Rhys</div><div class="ubbcode-body">What are the chances the base is not 20moa, and is in fact 0moa? </div></div>

The chances are zero, as I the difference between the two is clearly visible. Even though it would be obvious, I checked again anyway. Thank you for the suggestion.

 

[BlackWhiskey]

Re: Out of Elevation

Also, I forgot to mention, that I did take it to the range and fired 10 rounds of FGMM, and had the same result (+/- .5 mils) as I was reluctant to base the entirety of my conclusion on bore sighting.