Nightforce Benchrest 12-42 x 56 running out of elevation

[Matt P]

I don't think that's right. Your bullets must be traveling very slow if you can't get to 800 metres with a BR and 20MOA rail. If I'm reading what you've said right that means you have 70moa total now?

It depends on many things, such as how straight and well fitted the barrel was and the outside of that action compared to the centerline of the action etc.
Matt P

[KHGS]

What Matt is referring to is "tolerance stacking"! The Omark receiver has a thread into which at one point or other has had an adaptor screwed into it, then a barrel is screwed into that. All of those "fit ups" have tolerances & if they all "stack" in the same direction the bore of the barrel is not on the action centreline. Then there is the outside of two parts that are more than likely not perfectly in line as well and if this "misalignment" is in the same direction as the other "stacked" tolerances there is the problem. I have fitted hundreds of adaptors to Omarks over the years and I take a lot of care in fitting them to have everything "line" up as close as possible, but every now and then there will be the need to add taper to the base to allow the 'scope to have enough adjustment to get to 1000 yds. Whilst carefully set up Omarks can do a good job in F-class, precise they are not. I guess it all comes back to you get what you pay for, I run several Barnards & have no trouble getting to 1000yds with both 8x - 32x & 12x - 42x Nightforce 'scopes.
Keith H.

[johno]

Good to hear you are all fixed up and can enjoy your shooting again

[Omark44boy]

What Matt is referring to is "tolerance stacking"! The Omark receiver has a thread into which at one point or other has had an adaptor screwed into it, then a barrel is screwed into that. All of those "fit ups" have tolerances & if they all "stack" in the same direction the bore of the barrel is not on the action centreline. Then there is the outside of two parts that are more than likely not perfectly in line as well and if this "misalignment" is in the same direction as the other "stacked" tolerances there is the problem. I have fitted hundreds of adaptors to Omarks over the years and I take a lot of care in fitting them to have everything "line" up as close as possible, but every now and then there will be the need to add taper to the base to allow the 'scope to have enough adjustment to get to 1000 yds. Whilst carefully set up Omarks can do a good job in F-class, precise they are not. I guess it all comes back to you get what you pay for, I run several Barnards & have no trouble getting to 1000yds with both 8x - 32x & 12x - 42x Nightforce 'scopes.
Keith H.

Hi Keith

That is the conclusion I came to whilst waiting for the rifle to be looked at, and thinking about the issue, I just didn't know that tnere was a term for it. My rifle came with the adaptor already fitted, when, & by whom, I have no idea. Good to know that my thoughts were roughly right, just like my Omark.

I believe that you and MattP are correct. Anyway, something new learned.

[280Zastava]

Hi guys .
Got same problem on 2 x omarks .
1 with vortex goldrn eagle in 260 rem with 33moa zero for 300yds
I with nightforce in 308 with a 31 moa zero .
Can only just hit the upper stop with the vortex at 1000yds .
Got q store chasing info from YCI who supplies them . As
I reckon you need 50 odd moa rail for Omarks to utilize the scopes
full range of elevation . Other than YCI I have just got 18inch of blank
piccy rail for a machinist mate to mill to 55moa .