I have a 2.5-15 x 56 Z6 on a Sako in 6.5x55 SE. The gun will shoot sub-MOA all day. However at 300 yards and 15x mag I get severe horizontal stringing (say 6-8 inches) but almost no vertical stringing. The scope is mounted in optilocks which are torqued down and all threads treated with soft-set Loctite 243. The parallax turret is set for the appropriate range. I would be willing to accept that this is my fault due to inconsistent trigger pressure, except that it does not happen if I wind magnification back down to 8x. All of this was noted on the same day, using a single batch of handloads and shooting off front and rear rests. Anyone else seen this or got any ideas. Swarovski UK have NOT been very helpful so far.

Pat

Is the reticle more or less in the middle of its adjustment range? If not, maybe you have a case of those misses according to head position that is not classic parallax but caused by not aiming squarely through the objective lens.

Thanks that is a good thought. I will check how far through the adjustment range it is. I don't recall having to wind in a lot of adjustment....

Will post what I find.

A short update. I sent a rather harsh mail to Swarovski and they now want the scope sent back to Austria. I will probably do this, but will check the mounts once it is off, to make sure nothing else is contributing to this problem. Will keep posting here so there is a clear history of what goes on.

Pat

The scope went off to the factory on Friday. The mounts were absolutely solid. According to the factory, the maximum possible error with a scope set to be parallax free at 100 metres, would be 5.6 cm at 300 metres. My error was far worse than that, and I have parallax compensation. Interestingly, the parallax turret could be turned some way past the infinity setting (some reference to Buzz Lightyear seems appropriate here) so I think it may be out of calibration.