Variances Effecting Accuracy?


PDA






moonzapa
November 11, 2012, 10:01 PM
Not long ago, my good friends on this blog kept me straight regarding variances in cartridge overall length. (COL measured from the ogive of the bullet to the bottom of the cartridge.)

However, now that I am aware of bullet ogive variances effecting the COL, I measured fourteen 30-06 Springfield loads that I just loaded on my Forster Coax handloading press. I am using Hornady A-Max 168 Grain bullets and Lapua 2x fired brass. My target COL was: 2.672", (.010 off of the lans)

Here are the results using my RCBS electronic digital caliper and Hornady 30 caliber ogive collet:

2.6740" 2.6725" 2.6750" 2.6700" 2.6725" 2.6760" 2.6760" 2.6720" 2.6755" 2.6730" 2.6735" 2.6740" 2.6720" and 2.6720"

The COL variance between the shortest and longest was: .006"

My target COL for all cartridges was 2.672" which would place the ogive of the bullet .010" off of the lans of the barrel when chambered. However, as you can see above only 5 of the fourteen loads will be seated at "approximately" 2.672".

Have any of you noted the variances in your reloads? In my experience, Nosler bullets have less variances and it looks like I will be using more of their products.

Has anyone else experienced similar results? Maybe these variances won't affect good accuracy, however I am doubtful.

Thanks!

If you enjoyed reading about "Variances Effecting Accuracy?" here in TheHighRoad.org archive, you'll LOVE our community. Come join TheHighRoad.org today for the full version!
918v
November 11, 2012, 10:58 PM
It won't affect accuracy. Are you shooting them out of a rail gun or a hunting rifle? If you want zero variance, get some benchrest bullets hand made using a single die. Or you can sort the Amaxes using a comparator.

popper
November 11, 2012, 11:00 PM
Unless you have an ogive based measuring device you are guessing.

moonzapa
November 11, 2012, 11:06 PM
Thats a good suggestion. I have a Hornady Comparator. I was using the comparator after loading ammo. It makes more sense to check each bullet out before wasting powder, primer and bullet. I appreciate the help.

If you enjoyed reading about "Variances Effecting Accuracy?" here in TheHighRoad.org archive, you'll LOVE our community. Come join TheHighRoad.org today for the full version!