A riddle for y'all

[Chezney]

So I have a situation that has me flummoxed;

Have a new 6.5 Howa, Quick release mounts, S&B scope.

When trying to zero, rifle shot about a foot low at 100yds with scope adjusted Up as far as possible (yes I did try down as well). Thinking it was a scope/mount issue I put it on my .17HMR (usually with fixed mounts and a Nikko scope) for some cheaper testing. In the same configuration it did exactly the same, about a foot low. Swapped the mounts around, front to back, thinking if this was the issue the problem would be reversed. Nope! Same issue still.

"Ah, it's the scope" (with many expletives) I thought. But with one more role of the dice, just to be extra sure before i sent it back, I thought I'd just try it sat in my .17HMR's own, fixed mounts. At 100yds, with the Up/Down and Left/Right pretty much in the middle of their range, I was hitting 1" groupings after a couple of very minor adjustments.

Now, I have my solution, which is new mounts and I could leave it at that. But being a curious so and so I'd also like an answer. Why is it that the quick release mounts gave the same problem regardless of which was on the front and back? I can understand it if the problem reversed when I switched them, as one of them would be dodgey, but for it to have the same problem when switched I just don't get it. (even when trialled on another gun etc.). 

Any theories would be received and read with great interest!

 

Thanks

[Dougy]

Howa. 

[Scully]

Are there no instructions of how to ‘middle’ your scope before fitting to rifle? 

[Dougy]

The thing is you only have to be 0.01 at your end to be 1 inch at 100 yards. It could be an accumulation of rail,mounts and scope adjustments altogether could give you a fair amount.

[scouser]

If not the scope or the mounts, that just leaves the gun.

[Lord Geordie]

Lay on your back, and shoot upside down! Should have you shooting higher  

[Remimax]

your problem doesnt make any sense with what you have described.