When I had my 284 barrel chambered, I seated the projectile with the boat tail level with the base of the neck as you have done and sent the dummy round and barrel to Mitch Maxberry in Wellington who did the work and did it well. Seated at the base of the neck, a 162eldm is about 10 thou off the lands and shoots great right there. Whatever reamer he has seems to be about the right throat length for the ELD-M.
Bookmarks