Quote History Quoted:
Measurement was done by dropping a rod down to the bolt face and marking it. Then inserting a projectile and pushing it into the lands then marking the inserted rod again. That gives coal for that round..
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That method has two drawbacks that came to mind.
1. It measures to the tip if the bullet. Tips on HPBT bullets vary quite a bit (+/- 0.010"). That means that within the same box of bullets you could be off by 0.020" just because you randomly picked a long one (or a short one).
2. Bullet ogives and bullet OAL changes quite a bit from die-to-die, lot-to-lot, even though they are the same maker and same part number.
3. I'm not sure how you marked and measured the two dimensions but when I tried that I could not convince myself my numbers were accurate to within +/- 0.010".
Add to the above the fact that it is not the tip that's important, it is the engagement of the ogive into the lands that is critical.
It all adds up this - buy the Hornady gages. You'll get accurate, repeatable numbers to work with.
There are ways to get those numbers without buying the gages but it requires more work on your part and I don't feel like typing out the instructions right now.