Hornady OAL gauge and bullet comparator initial results


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AussieInUtah
February 18, 2012, 12:43 AM
I tried the Hornady OAL gauge and bullet comparator this evening for the first time with my Savage 10 LE .308 rifle and a Sierra 175 gr SMK bullet.

Here's 10 independent measurements from the case head to the ogive:

3.279"
3.273"
3.268"
3.275"
3.275"
3.273"
3.272"
3.273"
3.274"
3.275"
3.274"

Average: 3.274" Standard deviation: 0.003" Range: 0.011"

Oh, yeah... guess I should be subtracting 1.000" off those measurements to remove the length of the comparator and bushing.

Maybe I should delete the first three measurements because I was still getting used to the device.

Given that I'm going to try seating the bullet about 0.020" off the lands, is this level of accuracy good enough? How accurately are other people measuring their bullets with this device?

Do you guys repeat the measurement with a few different bullets from the same box, so that you can see any variation due to inconsistent bullet dimensions?

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Col
February 18, 2012, 12:49 AM
are you sure thats a 308 your measuring. seems way too long.more in the 30 06 bracket maybe

AussieInUtah
February 18, 2012, 12:55 AM
Like I said, I should be subtracting one inch off those lengths. The lengths I listed include the bullet comparator and it's bushing. The actual average length should be 2.274"

A-FIXER
February 18, 2012, 02:01 AM
Aussie, appx twothousands is the thickness of a human hair, I would not think it would throw the POI off to much just shoot'em and see what happen in your rifle. now you know just how imperfect those mfg'd projectiles are. Good job and good luck let us know how they shoot.

AussieInUtah
February 19, 2012, 12:56 AM
Probably won't get out to shoot again until next weekend. I'll post my targets on the forum then. Thanks for the advice.

NeuseRvrRat
February 19, 2012, 07:38 PM
if you throw out the first 3 measurements like you said, the amount of variation you got is so small it could be attributed to how hard you pushed the bullet against the lands or how hard you pushed the comparator insert against the bullet. in other words, these appear to be acceptable numbers. you should be fine by loading .020" short of the average.

sugarmaker
February 19, 2012, 07:44 PM
the plastic rod does have some flex, there is a bit of technique required. Mine is within a thou if I am consistant.

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