Re: sorting by ogive length -how close is close enough
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Dave Tooley</div><div class="ubbcode-body">For what it's worth. I very familar with several, meaning more than two, bullet manufactures. I know of no one that mixes lots of bullets. Take Sierra for example. They may have added another bullet by now but several years ago there was only one bullet they made that was run on more than one press at the same time. That was the 30 cal. 168gr. HPBT. Bullet dies last a long time and are very expensive. Why would a company want to invest in more than one set until they were getting near the end of the life cycle of the tooling. That life cycle can be 3-5 million bullets.
Small variations in ogive to base length happen for several reasons. Unless you've made bullets and have seen a bullet press running it's hard to explain all the factors such as jacket lube or how the dies are set up and held in the press that effect the bullet during it's manufacture. Years ago we did get mixed lots that's not the case anymore. I've measured the BC's of bullets that had a ogive to base variation of .030". They came out of the same box. For all practical purpose they had the same BC. Sort to the tolerences that give you confidence. A range of .005" will not show up on the target. What you'll probably find is that your culls used for fouling shots and coarse sighters will shoot to same place.
Far more important is the effect the meplat has on the bullet. Irregular meplats cause variations in inflight bullet yaw resulting in variations in BC. </div></div>
If anyone's in a position to know this, Dave would be the one, and I'll gladly take back my measly $.02 where' his opinion is concerned.
I was told years ago that Sierra ran certain lots from three different presses and they all funneled into a single collection area. These were words from a Sierra technician, not hearsay, when I specifically called asking about variations in ogive to base length in 240 SMKs. This must be the "years ago" that Dave speaks of in his post. Whether the technician "misspoke" or things have changed. I also have a box of Berger 185 VLDs, same lot, that vary up to .030" in ogive to base length. I keep them just to show. It's nice to hear that manufacturers have stopped the common area collection practice, and Dave's words on lack of B.C. variation is sure going to save me some time. I guess some things do get better with time. Thanks for the comments Dave.