Recently I was advised to move my sling up (it was more or less like on this pic: link) and that generally made my position better - I feel more stable, and Scatt confirmed that: usually I've got 99+
But when I tested with live ammo - every 3-5 shots have unexpected flyers to the left (around 8 o'clock). After shot I call it as solid 10, but indeed it is 9.. (see pic 1 below). I was advised that this happens because of weak buttplate contact - then cheek pressure during recoil moves the rifle butt to the right.
Question: how to ensure constant solid contact with the buttplate?
Also, my position seems to get much lower after 10 shots - so I have real trouble constantly stretching my neck in order to reach a sight. (As I suspect - neck should be relaxed, not tensed up and stretched forward?)
So the rifle kind of moving forward - and this weakens buttplate contact and forces to stretch in order to reach it.
Please see 2 animated photos here: they show start and end position
http://www.dianaserver.net/rasnoe/shoot ... imate.html
I also note that my eye relief is 8 cm. This seems way too far..
Can this be because the buttstock is too long for me? (see the pic2 below).
Or what should I try to do - move handstop forward, shorten the sling, or just move right shoulder and elbow back, more rotate body to the left, etc?
I've tried shortening the sling - but it doesn't seems good, since it increase pressure on the left arm and causes fatigue..
pic1:

pic2:
