The list of possible causesfor vertical strings is a long oneof which may include; rest, rifle/shooter positioning, recoil, rifle balance,bedding, barrel heat, to light or heavy of load(charge), fouling, etc.

FYI,link:http://www.6mmbr.com/verticaltips.html

You should be able to narrow the potentials by systematically reviewing the results and looking for changes in load, etc that may have resulted in the vertical string. If you can't narrow it down this way on your next range visit try the loads that strung first to eliminate shooter fatique.


BTW I had a vertical stringyesterday from a lead sled. This was a proven tested load but is on the high side in my rifle. Inoticed my muzzle flipped more then normal with the sled. I moved back to my sandbags and shot a normal group. So it is possible the rest is the culprit however had I not known the load was good I would have assumed i was too high and backed off a touch. I also know my rifle very well so bedding, etc can be ruled out. However seeing your rifle is new you must take a much longer route to eliminate possibles.

G/L