Re: 7STW/Berger 180VLD hunt
To find the seating depth in my rifles, I use a dummy cartridge and a fiberglass rod.
I assemble the dummy round longer than I could possibly use, and place into the chamber without the bolt. I push the round as far as it will go with a finger. I then insert the fiberglass rod into the muzzle and push against the bullet, while at the same time "feel" the resistance with my finger on the case head. If there is any resistance, I make the cartridge about .010" shorter and repeat, until I feel NO resistance. I know then, that I am within .010" of the lands. It works perfect every time.
Sometimes I get lucky, and get it close right away. Sometimes as you get closer to the lands, you can feel a difference in the resistance, and start changing to .005" instead. I seat my VLD's .005-.007" into the lands.
AR-10T in .308 & .243 both 24"
700 LA 7 WSM 30" 5R
AR-15 Rock River lower, WOA 26" varmint upper
Savage/ Broughton 23" .308