Electronic targets Bisley

[Montey]

I was at Bisley last week on an NRA club day my first time on the electronic targets at 600y all went well and apart from needing to find a difrent technique or rhythm so I didn't rush my string I had a reasonable score.In the afternoon i shot the 1000y I was using my FTR rifle with the old 5 turn Night force scope I use the later model 10 turn version on my open class 300wsm and have shot this on the same target once before.i encountered a problem straight away as I lined up the reticle on the white vbull the reticle split optically.This did not happen on any other serfice  I aimed at no amount of adjusting made any difference and to ad to my problem I needed anything from 6-10 minutes of wind.Has any one else had a similar problem ? The plot sheet looked really bad the worst score I've ever maid at a 1000y.