Chasing the lands!

[M118LR]

I've never had much luck chasing the lands. I realize that the object is to center the Projectile, yet how many projectiles have a perfect curcumference? So the added pressure of a Projectile without any free bore has always managed to undo any gain I've gotten from centering the Projectile on the lands. I'm sure there are others with differing experiences. Are we actually chasing the lands, or is it more important to adjust seating depth to maintain the node? Please opine. Thank Y'all.

 

[HSmithTX]

Depends on the rifle, in my 308's it doesn't make much difference, usually less difference than I can shoot. My primary 308 hasn't had the OAL changed at all in 400 rounds and still hammers. In my 28 Noslers the throat moves FAST and it does make a difference and that difference is big enough that I can shoot it pretty easily. I will adjust it every 50-100 rounds in the 28 and usually 50 since I load 50 at a time for them, in my rifles it's as simple as measuring to the lands and whatever the difference is from last time it was checked is the distance the OAL gets changed by, rifle goes back to shooting small again. I run the 28's close to the lands, if the window is 10 thou long where it shoots well I will load on the long side of that so that as the throat moves out I am shooting through that 10 thou window and it stays shooting well until I need to load more.

 

[M118LR]

In .308 I found that a couple of extra grains of IMR every 2K rounds kept me inside the nod without requiring OAL adjustments until it was time for a new barrel, but I wasn't pushing MAX loads with either 168 or 175 SMK 's. So that was chronograph driven.