wkdickinson
Gold $$ Contributor
OK, I just purchased a box or 500 Berger 6mm 105 Hybrids. How should I sort them - by weight, by bearing surface length, by both, does it matter?
Yep we did, and just like Lincoln stated if you ask 5 people you'll get 5 different answers. If you wanna go over board come on over. I check length sort, diameter sort, base to ogive sort, bearing area sort and then I wonder is it worth it?We just had this conversation![]()
Wasn't it just yesterday?We just had this conversation![]()
How do you measure, COAL or base to ogive?On a separate note: I loaded up 100 rounds of Berger 140's 2 weeks ago and never checked the ogive bearing area ( it was from a different lot #) my mistake. After I loaded 85 of them I thought wow I never checked my seating depth and on a Wilson arbor press it doesn't change but guess what on this lot of bullets I was .006 off of my go to load. I ran that load on a Saturday morning in open F class and shot a 599, would all that measuring helped ..... I doubt it. Just makes you wonder how much it's worth.
Darrin
I sort Base to ogive and over all bullet length. If you don't sort Bullet over all length prior to seating you will find a large variation in coal. I sort bullet over all length just for piece of mind. Can you see it on paper, probably not.How do you measure, COAL or base to ogive?
She's all good. I wondered what could be achieved if you sorted COAL only or COAL first.I sort Base to ogive and over all bullet length.
Nope too much time in what I'm doing now and it works excellent for me.She's all good. I wondered what could be achieved if you sorted COAL only or COAL first.
Ever thought of doing a base to ogive sort first, then meplat trimming each batch and then measuring to see if there's any discernible difference in COAL?![]()
This is the link to what some of the posts are talking about http://forum.accurateshooter.com/threads/bbto-or-bearing-surface.3966113/OK, I just purchased a box or 500 Berger 6mm 105 Hybrids. How should I sort them - by weight, by bearing surface length, by both, does it matter?
Why is it so popular to use the case head as the reference to any measurement to some point on the bullet?
Case heads are typically not against the bolt face when the round fires. A few to several thousandths clearance is the norm.
The case shoulder is against the chamber shoulder when the round fires so it's a much better reference, in my opinion. Unless all the cases' headspace is the same.
Because it's the bottom of the cartridge and one needs a place to start all measurements from.
So if all shoulders are set to standard length
Measured from case head to shoulder, then it's safe to assume all measurements will be equal if bullets are sorted by base to ogive
Giving one a very consistent cartridge to cartridge measurement.
Now do cartridges have headspace or do chambers?
My understanding as per the teachings of
Sir F Guffy, the chamber does.
All of this would be mitigated if seater stems touched bullets at their diameter where the chamber throat's rifling does. That place is typically a couple thousandths less than bullet diameter.The seating die stem pushes down bullets from a specific contact point on the ogive slightly below the meplat down to whatever setting the die mic has dialed in; it doesn't "know" that the bullet has BTO variance below the contact point.
Only if the bullet's ogive reference diameter is where it touches the rifling. And all cases headspacing on their shoulders have the same headspace.Measured from case head to shoulder, then it's safe to assume all measurements will be equal if bullets are sorted by base to ogive
Giving one a very consistent cartridge to cartridge measurement.