does any one use the sierra 155gr tmk in the 308 at magazine length 2800" ? i have a box that i wish to use ,i have n140/n150/h4895 powder ,i can not get close to the lands in my rpr and wish to feed them from my magazine.i know sierra say they are best from 20 thou off the lands but this would not leave enough bullet in the case. and wondered if any one had had success with the mag length seating. i will be trying them at so point.