Yes the O ring does work. I put a small strip of leather down with wood glue on either side of the bolt hole on mine which also works, or doesn't hurt. Sanding the forend so the barrel doesn't touch also helps. I like it when I can slide a business card all the way down either side of the barrel smoothly. With hand loads mine will shoot a 1 inch group at 100 yards ... 170 grain Remington or Hornady bullets and 29.2 grains IMR 3031. Powders change, the max load for IMR 3031 used to be 30 grains but now the max is 29.2. Mine shoots almost as well with Federal 170 grain Power Shok ammo. Many report 150 grain factory ammo also shooting equal groups. The reports on the new Hornady 160 grain pointed bullet ammo is that it does not shoot as well in the Handi ... I also found that to be the case. Bullet performance at 100-150 yards is excellent on deer, I've shot a lot of them over the years with a 30-30. Where people get in trouble is when they over shoot the rifles ability or just bad bullet placement.