Home Forums Reloading Big Game Rifles Hornady OAL Gauge?

Not to steal from Stick, but "1,000 words"

Here are factory loaded Hornady Match 75 gr HPBT. Why the hell do I have factory ammo? 'Cause I just picked up a NIB Tikka 1:8 223. Rule #1 for any new rig for me is 1 box of factory JICIFU (Just In Case It F**ks Up) and to see some sort of "baseline" I'm dealing with. My gun, my rule. Anyhoo....

2 measurements here: Cartridge Over All Length (COAL) and Base To Ogive (BTO)

COAL measured this way:


BTO measured with 22 cal comparator insert:



Chart below tells the tale. You can see the variance measuring to the tip of the bullet vs. ogive with standard deviation shown below.



Stealing from the big man again, the $0.99 Sharpie is a reloaders best friend. The line on the top is where the seating stem hits the bullet when performing the seating operation, the line on the bottom is where the comparator insert hits the bullet when measuring.




You could take 10 sets of calipers and 10 sets of inserts and get 10 different results, but I doesn't mean jack schit. What matters is that if I want to reproduce that particular COAL, I'll spin out my seater stem (with the die itself at least 1 1/2 turns off the shell holder, yet another long story) and turn it in until my calipers (with comparator attached) reads 2.836. Why 2.836? Because 70% of the sample says so with MY calipers and MY comparator.

Now, if I'm sitting around bullschitting with the fellas and they wanna know my COAL I can say anything from 2.226 to 2.232 and be correct. I'd probably say "2.226" since that's the mode. It doesn't matter because when I make another lot, the BTO is the number I'm dialing the seater to and the number that matters. And to make life easy, micrometer stems (Reddings for me) are next in line to being buds with the Sharpie....

Your schit has to be relative to your schit. Not a book, bubba, or Campfire bonehead.....