Here ya go. http://www.accurateshooter.com/techn...torque-tuning/

Tell us what you've done to inspect her rifle and confirm everything is tight and correctly adjusted. I've seen guys show up on the range with actions loose in the stock, scopes mounted backwards, you name it. Not saying your sis's rifle suffers these faults, just making suggestions.

Also, tell us how you check for and clean out copper buildup. My 6.5 with EABCO accuracy barrel is a copper mine. 5 shots is all I get before accuracy starts to seriously degrade due to copper build up. I use an endoscope camera and the view down the muzzle shows bright copper on all lands and grooves after just a few rounds of shooting Bergers, SMKs etc.