My Tikka T3 SS .260 was a very so-so shooter out of the box. About 1 1/2" groups at 100yds with every load. It flunked the free float test with a piece of paper between the barrel and stock. After fixing that and noticing some divots in the aluminum recoil lug, I replaced it with a Lumney titanium.
I found I could not approach the lands when seating handloaded bullets, so I modified the bolt stop and magazine to accept longer cartridges that nudged the rifling.
After doing all this my first 5 shot group at 200yds was 7/8", and since verified many times.
Not sure which "tweak" did the trick but now I'm happy with it.
