two different lot numbers

[misser]

of the same size .264 sierra 120 gr matchKing bullets. expected some difference ,but not that much.

 

[spife7980]

And the take away from this is… ?

 

[misser]

And the take away from this is… ?

you don't know until ya test

 

[AllenOne1]

What are you measuring here? What does each bullet weigh in this example?

 

[misser]

What are you measuring here? What does each bullet weigh in this example?

bullet weight is the same . what?? was my first thought how can that be ?? . I have 2 other lot numbers in box, not opened ,don't know that I want to . not yet anyway

 

[misser]

what am I measuring ?? is not the length of the bullet . its the ogive to the same size diameter on the boat tail

 

[DeathBeforeDismount]

The point he is making is on paper it probably doesn't matter. Just go shoot and stop worrying about stuff that does not necessarily translate to results downrange.

Bullet lots have varied since the beginning of time and will probably continue into the foreseeable future. What matters is how they perform. Generally Bergers shoot great across lots same as SMKs. DTACS's (made by sierra) seem to be the exception and no one shoot hornady who cares about their scores so best to just ignore them.

 

[Doom]

what am I measuring ?? is not the length of the bullet . its the ogive to the same size diameter on the boat tail

What you are measuring is akin to the bearing surface but depending on the inserts it's probably not giving a true gauge. Small variations in the ogive radius or boat tail angle will case variations which have no bearing on the performance of the bullet. Small variations in boat tail angle or length has almost no bearing on internal ballistics. While many people profess to see the difference in jump it may not be as sensitive as some seem to see on small sample sizes. That said, consistency in jump is important. What we do know is consistency in CBTO will put the bullet in a consistent jump which does seem to be a very important parameter for precision, probably more so than consistent bearing surface (IMO).

 

[straightshooter1]

What you are measuring is akin to the bearing surface but depending on the inserts it's probably not giving a true gauge. Small variations in the ogive radius or boat tail angle will case variations which have no bearing on the performance of the bullet. Small variations in boat tail angle or length has almost no bearing on internal ballistics. While many people profess to see the difference in jump it may not be as sensitive as some seem to see on small sample sizes. That said, consistency in jump is important. What we do know is consistency in CBTO will put the bullet in a consistent jump which does seem to be a very important parameter for precision, probably more so than consistent bearing surface (IMO).

A few years ago I ran a test to get some idea what a difference is bearing surface length makes as I saw a difference between two lots of my 168 SMK's of ~.034" (it being a comparator measurement and not exact measurement of the bearing surfaces). What I found when comparing 20 rounds of the shortest to the longest, there was quite a difference in MV and a shift in POI. But I think one has to have a big difference in bearing surface length to see any such changes. I don't think one going to see enough difference within a lot (at least, not with the higher quality bullets) that would result in something than can be seen on target. . . at least, I haven't seen it with any lot of bullets I've had.

Here's that data taken from my chrono (when my reloading process wasn't as good as it is now ):

 

[OREGUN]

We are looking at Sierra bullets here. Not exactly the standard-bearers of lot to lot consistency.