When I purchased my 25.06 about 5 years ago, I worked up a custom load which was 20 thou of an inch back from the lands. Lovely grouping - no problem! I got the max OAL by feeding a spent case with lightly fitted bullet head in so that the lands seated the bullet. However, I was curious to see whether this might have changed. To my surprise even with the head only just inside the case, it doesn't make it as far as the lands anymore!! The rifle is still very accurate. I can only assume this is due to throat erosion? If this is the case, the distance the bullet jumps must increase by a tiny amount every time the rifle is fired due to wear? My question is, should I be chasing this 20 thou" sweet spot or just keep my loads at the length it liked originally. As I can't make it 20thou back anymore I think I already know the answer, but I'm curious to know how barrel wear affects accuracy of developed loads as the bullet jump distance increases? Any thoughts or ideas welcomed.