boilerpig1;
While I've not played with lots and lots of 99's over the years, one thing that I have learned to pay attention to on any rifle with a 2 piece stock is how the butt stock is bedded onto the action.
On something like a .308 level recoil rifle, if it was a 99, Ruger No 1 or Winchester/Marlin lever action, I'd be tempted to bed the front edge of the butt stock so there was a perfect fit between the front flats of the wood and the rear flats of the action.
Some I've even bedded so there is 100% contact with the flats and tang - such as a Marlin Guide Gun or a .300 Win Mag No. 1 - both of which benefited from the bedding.
While you have it apart, check to see if any cracks are happening in the butt stock too, as I've worked on at least one 99 that I can recall where a cracked butt stock caused the groups to go wacky.
Hopefully that was some use to you or someone out there sir. Good luck in getting your rifle tuned up and all the best to you in the upcoming week.
Regards,
Dwayne
