Lesson in bullet lot variations

[Texas10]

I got a lesson in bullet lot variations today. I was loading 50 gr V-Max from two different boxes (finished one, opened new one) to an Ogive dimension and was getting .015 variations after seating. Thought my Lee seating die and gone tango uniform, then started measuring the weight, OAL and base to ogive of several bullets. Had to pull 10 rounds, sort bullets and reload. Start to finish about an hour of head scratching and lost time. Lesson learned.

Is this a normal occurrence with Hornaday, or should I be buying lottery tickets today? :o

[LongRange]

first...if your not...you should be using 2 comparators to measure your ogives(one on each blade of to calipers)...measuring off the base to ogive is not going to give consistent readings.... .015 is a big difference but is possible as most all bullets vary lot to lot...so yes its normal but ive never had bullets with that big of a spread but like i said its possible.

[Texas10]

LongRange,
Would you mind further explaining about base to ogive measurement? I'm a newbie to reloading and still trying to fathom it all.
This is what I did, and what I found;

I had dumped 10 from box labeled p/n 22616 (qty 250) and 15 from box p/n 22261 (qty 100) into a small bowl to aid loading, so I had to measure all to get them sorted. All measured with Hornaday Comparator on Hornaday digital calipers.
p/n 22616 lot measured base to ogive .385 and OAL was .775
p/n 22261 lot measured base to ogive .398 and OAL was .768
All were weighed. The only difference between the p/n's was qty in box. They are supposed to be the same bullet.

All were very consistent within the lot with one exception of one bullet weighing .1 gr more on my balance beam scale.

Those numbers made me think the new batch had a much different profile as it was shorter and ogive was further forward, like it was an A-Max instead of V-Max, but as far as I know, they don't make an A-Max in 50 gr.

Normal lot variation?

[LongRange]

this is what im talking about......

http://i1239.photobucket.com/albums/ff515/LTT-/Mobile%20Uploads/photo-42.jpg (http://s1239.photobucket.com/user/LTT-/media/Mobile%20Uploads/photo-42.jpg.html)

the base of the bullet is most likely whats giving you the big spread...while im not a hornady fan they are some of the most consistent bullets ive measured...the bullet in my calipers in the pic is a hornady 6.5mm 140g match...i just now pulled 6 out of a box and measured them...using the two comparators all 6 are 0.0648.5...with out the top comparator i get a 0.008.0 spread between the 6 bullets....so the BASE in the 6 i just measured vary .008 NOT the ogive...also the ogive to lands is a much more accurate measurement than the COAL as the bullet tips vary more than the bases.

the comparator on the top blade is where the boat tail is and i keep these two comparators seperate...the bottom one is only used to measure ogive to lands when im seating bullets.

[Texas10]

Ok, I'm seeing the difference in the way you measure and the way I do. Thanks for taking the time to research that, LongRanger. I appreciate your input and wisdom. Which brings up the difference between where my seating die contacts the bullet and where my Hornaday tool measures, they're not the same place and any difference in bullet profile will change the seating depth. I get that, but it seems to me that what I found is a whole lot of difference between 2 lots. So lesson learned! Don't mix lots!!

[BillPa]

Ok, I'm seeing the difference in the way you measure and the way I do.

Don't mix lots!!

Yeah, the bases of bullets can vary as much the tips at times why the correct way to measure is from the heel to ogive. Mixing lots? I opened a new box of fifty 6.5-120 brand name bullets last fall. About half measured .571" heel to ogive, the rest .581-.583". Its not only lot#s that vary at times.

Bill