Thanx for any comments/advice in advance. Have a m16 in .308 win. Have the Hornaday OAL guage to measure the base (bolt face) to ogive. I get 2.83 with Hornady 150 gn sp interlock #3031. Using 20 thousandths as a starting point to seat the bullet off the lands, (2.23 - .020) I seated bullets to 2.21. The bullet was seated WAY below the crimp ring, and left me with about 24/thousandths bearing surface. It is my understanding (confirmed by both Hornady and Sierra) that the bearing surface should be at least as deep as the caliber of the bullet (.308), which would be 1.992. Waaaay off the lands. Am I over thinking this? Are my calculations wrong? Anybody have a m16 in .308 they can measure for me??