horizontal string

[albertaboy]

Just started loading for a rebarrreled 7mm STW. when i shoot 100 yd. groups I get horizontal strings. About 1.5" groups.loading 77gr. of IMR 7828 behind a 160 gr. barnes TSX in new lilja barrel. any suggestion would be appreciated.
thanks. /ubbthreads/images/graemlins/cool.gif

 

[270WSM]

Need more info. Is that the only load you have loaded? Have you tried different charges, seating depths, powders, bullets, etc....??? What type of rest are you using? How's your bench technique?

 

[REV]

What is the trigger set at?