Just putting a few loads together and using my new comparator. I know what some of you are thinking - put the stupid thing away it just causes problems... Well it has certainly made me think. I am getting loads varying by up to 0.015" head to ogive without moving the seating die.
I pulled the die apart and measured the oriface that seats the bullet. It measures about 0.2". It's a 243 btw. Comparator measures .236 as does the rifling I imagine (give or take a couple of thou).
As the seating die is seating the bullet way up on the nose where the diameter is 0.2", unless every bullet has exactly the same curvature, the ogive to head length will always vary, and by up to 0.015" (or more sometimes) with these 80gr remington PSPs. Now I know a few variations won't hurt hunting accuracy that much, but I would have thought this is a bit much. What do people think, could this be part of the problem here - Flyers ? I will be trying some other bullets ASAP at least.
For the moment I've adjusted the die for each bullet to give me 0.01" off the lands, but this is not on for big batches. How about I drill the seating mandrel out to .236? Will that give it too little bearing surface - will it just bight into the bullet and grab it - maybe even permentaly or at least giving a false reading?
Has anyone else thought about this problem? What would a redding competition die measure?