Re: how far is too far to jump a berger
I don't think anyone knows why certain distance to the lands matters, but it does for sure.
At what distance YOUR barrel will like? No way to know or predict it...
There is no set value. It's simply the best you can do with what you have. Could be anything.
What I do is pick a distance to begin that leaves room for adjustment both ways. I use a random, moderate load, and adjust seating for tightest grouping. Then I follow up with powder adjustments for better grouping still. Then I tweak seating both ways to validate that it's right where it should be(in it's performing band).
Since you'll have to be ~120 off, you can start at ~130off and adjust for best grouping with what your bound to. Then, load develop with powder, etc.
If the bullet doesn't give you what you need from there, change bullets, or concede to single shot with a follower instead of a magazine, and start over.