Bullet Base-to-Ogive Comparator Data

[Silkrider]

On a boat tail bullet, you measure the actual bearing surface. That is from ogive to the start of the boat tail. The tools don't measure or support the bullet off the base.

Given the above, what does the flatness of the actual base of the bullet have to do with the bearing surface? What am I missing here?

By measuring the bearing surface, all I am interested in is the amount of surface area on the bullet that comes into contact with the barrel.

If you soft seat your bullets into the lands, this should give you the most consistent engagement in the rifling and bullet friction in the bore.

The above works will enough that single digit ES and SD numbers are the norm in the calibers I shoot.

All my shooting is prone, sling, iron and scope sights at 600 and 1000 yds.

Bob

I might be missing something also but,
my 155.5 full bore load is set .015 off the lands. I just got a batch of bullet that were .045 longer ogive to bottom of boat tail.
now if I load them .015 off the lands from the ogive that will keep my overall length the same but will put .030 more bullet deeper into the case.
won't this change my case pressure?
Thanks
Silkrider67

 

[mikecr]

Silkrider,
30thou of of neck tension change with a .308 means nothing. Just as 30thou of actual bearing means nothing.
Won't affect a thing
If 15thou OTL initial is tested as best, this equivalent CBTO is a better attribute to focus on. THAT CBTO will matter.