Im curently loading for m 280, and have found a couple different loads that are shooting very well, but could use some tinkering. Have tried slightly adjusting charge and dint come up with anything. So now im adjusting my seating depth. The question is, seat deeper or closer to the lands?? Im getting a couple shots to touch, then usually the third will move an inch or so...
I have found that heavy for caliber bullets usually need to be seated closer to the lands than lite for caliber bullets. In my 6-284 and 22-6mm if you take a bullet out of the chamber you will see about .010 of rifleing marks on the bullet. BUT, you never know for sure where to seat your bullet untill you try.
I would not go much closer than .002" of the lands with a 7mm bullet, but then again some types like to be seated touching in my cases. (long VLD's) What I think I'd do is load six rounds about .010" off the lands, and another six about .005" off the lands, with a third group about .0025" off the lands. Then try them to see if it helps. I've found that the closer the bullets are to the lands, the more consistent they are. I always seat my 6mm and .223 bullets within .003" of the lands; if not just touching the lands. I have done some testing with the bullets jammed into the lands about .005", but see little if any difference so far. I may go back and make some small changed in the tension on the neck to bullets to see if that makes any serious changes with the bullets jammed into the rifeling.
Thanx for the input guys. Im new to reloading and on a buddys advice, i seated the bullets at .0030 off the lands. Im loading some now at .0020 and .0015 and gonna take it to the range tomorrow. Like i said, im a lil green and just needed some advice. Thanks alot!
Something to consider here too is that if the bullet is seated very close or touching the lands, your chamber pressures will be higher. So if you start to run into pressure issues during load development at all try backing your bullet off the lands a bit.