Morrey
Member
I have a question regarding seating depth, accuracy and how velocity data interacts together.
I had developed a very accurate hunting load with Hornady's new ELD-X 178 grain bullet in .30-06. My rifle is a Cooper bolt action with a 24" 1:10 twist match barrel.
My load development was IMR 4350 56 grains at 2800 fps. The accuracy was great in my opinion for a hunting bullet at .350 MOA avg for two 5 shot groups.
So I get smart and purchase a Hornady OAL guage, Hornady bullet comparator and a Hornady modified 30-06 case. Testing went well and my ELD-X ogive touched the lands at 2.730". I figured my ideal depth would be backed off the lands by .020, so my optimum seating depth on the ogive would be 2.710. I go back and check a box of bullets I had loaded w/o the comparator to find the ogive was at 2.650, considerably deeper than my new data indicates. (But remember this bullet seating depth had previously given me .350 MOA)
I pull the bullets (collet puller) and reseat them at 2.710. On the range I have conflicting data. With a 10 shot test, two groups of 5 shots each, my accuracy with the new 2.710 depth actually was LESS accurate by .250 MOA. My new seating depth accuracy was .600 MOA...not bad for a hunting gun with a hunting bullet, but I went the wrong way accuracy-wise.
Here is my conflict....on my chrony, the new seating depth gave MUCH better ES and SD than with the previous load. With new depth I was getting several shots that were DUP velocity, and my ES/SD numbers were both single digits.
The chrony was telling me it likes this new depth, but the POI said not as good. There was no vertical stringing on the paper, only horizontal point of impact movement.
Any ideas on this data...this conflict is confusing to me. Or maybe MY BAD as the shooter pulling the shots? Not like me but what else can we figure? Did pulling the bullets gently with the collet puller scar the bullet enough to make a difference? But why is the stringing all horizontal and none vertical?
I had developed a very accurate hunting load with Hornady's new ELD-X 178 grain bullet in .30-06. My rifle is a Cooper bolt action with a 24" 1:10 twist match barrel.
My load development was IMR 4350 56 grains at 2800 fps. The accuracy was great in my opinion for a hunting bullet at .350 MOA avg for two 5 shot groups.
So I get smart and purchase a Hornady OAL guage, Hornady bullet comparator and a Hornady modified 30-06 case. Testing went well and my ELD-X ogive touched the lands at 2.730". I figured my ideal depth would be backed off the lands by .020, so my optimum seating depth on the ogive would be 2.710. I go back and check a box of bullets I had loaded w/o the comparator to find the ogive was at 2.650, considerably deeper than my new data indicates. (But remember this bullet seating depth had previously given me .350 MOA)
I pull the bullets (collet puller) and reseat them at 2.710. On the range I have conflicting data. With a 10 shot test, two groups of 5 shots each, my accuracy with the new 2.710 depth actually was LESS accurate by .250 MOA. My new seating depth accuracy was .600 MOA...not bad for a hunting gun with a hunting bullet, but I went the wrong way accuracy-wise.
Here is my conflict....on my chrony, the new seating depth gave MUCH better ES and SD than with the previous load. With new depth I was getting several shots that were DUP velocity, and my ES/SD numbers were both single digits.
The chrony was telling me it likes this new depth, but the POI said not as good. There was no vertical stringing on the paper, only horizontal point of impact movement.
Any ideas on this data...this conflict is confusing to me. Or maybe MY BAD as the shooter pulling the shots? Not like me but what else can we figure? Did pulling the bullets gently with the collet puller scar the bullet enough to make a difference? But why is the stringing all horizontal and none vertical?
Last edited: