I just purchased a Hornady Lock-n-Load Oal guage with a modified case for my 7MM Rem Mag ( Wetherby Vanguard Sub-Moa ). I cannot get a reliable reading! The case seems to set out ( with 168 berger just going into the case at the boattail ) and when it is shoved in hard the 168 berger is in the case right at where the ogive/ caliber hits. Ie: it does not hit anywhere that you could seat the bullet or give you a warm cushy on where the lands actually are.
I also purchased a bullet comparator for my Hornady caliper.
Just to make sure that I was doing everything right, I pulled out my wifes winchester 300 wsm
shooting 190 vlds and checked it. Her vld is at .100 off the lands and everything looks fine. Her gun shoots sub 1/2" groups all the time.
So, I resorted back to the split case method with black sharpie marker and came out with this for my 7MM Rem Mag:
Mag box max length: 3.5150
Overall ( base of case to tip of 168 vld): 3.490 touching lands
Length with bullet comparator : 2.790 touching lands
What gives with the wetherby?????