Thread: Testing a conventional approach to load development

Quite surprised theres not much focus on seating depth here. Remember watching a podcast with eric cortina and jack nerry (i think his name was) one f class the other benchrest for team lapua. Talking about seating depth has a direct relation on group size, testing in 3thou increments. A example of this is when people buy factory ammo to test what there rifle likes that is the seating depth of the different ammo that determines the better groups.
I think his way of load development makes sense, first stage over chony, no target to distract you, find lowest es
Once powder charge found on to seating depth testing

Originally Posted by Hunterdave

Quite surprised theres not much focus on seating depth here. Remember watching a podcast with eric cortina and jack nerry (i think his name was) one f class the other benchrest for team lapua. Talking about seating depth has a direct relation on group size, testing in 3thou increments. A example of this is when people buy factory ammo to test what there rifle likes that is the seating depth of the different ammo that determines the better groups.
I think his way of load development makes sense, first stage over chony, no target to distract you, find lowest es
Once powder charge found on to seating depth testing

Cortina's are so last year. They don't even make them any more.

You are assuming that factory ammo brands all use the same powder.
I test powders before I fiddle with length (if ever). Mag length and a couple or three powders at near book max. Usually one of them works. Chrono when it's all over and adjust the charge for target velocity. Then go hunting.

Originally Posted by Tahr

Cortina's are so last year. They don't even make them any more.

I stopped watching him ages ago.

Originally Posted by Tahr

Cortina's are so last year. They don't even make them any more.

You are assuming that factory ammo brands all use the same powder.
I test powders before I fiddle with length (if ever). Mag length and a couple or three powders at near book max. Usually one of them works. Chrono when it's all over and adjust the charge for target velocity. Then go hunting.

No just that any load can be made better at the right seating depth

Originally Posted by Hunterdave

No just that any load can be made better at the right seating depth

Show us your groups . . . Awaiting results with interest!

This was my first go at reloading in my last 284, no expert but went on the strategy outlinded. shot a ladder .5 increments over chrony, in hind sight I should have done 3 to see if they replicated. no targets used. Obvious node at bottom and 2903fps. Did another .3 apart around that upper node to see if I could pinpoint where it was. By doing this you can load to upper edge in winter and lower in summer. Went back and I did do seating depth test but don’t have any pictures of it, it was a couple of years ago. Was a tack driver so I was pretty stoked. About to do again so will see how it goes this time
1 5 shot & a couple of 3

Originally Posted by Hunterdave

This was my first go at reloading in my last 284, no expert but went on the strategy outlinded. shot a ladder .5 increments over chrony, in hind sight I should have done 3 to see if they replicated. no targets used. Obvious node at bottom and 2903fps. Did another .3 apart around that upper node to see if I could pinpoint where it was. By doing this you can load to upper edge in winter and lower in summer. Went back and I did do seating depth test but don’t have any pictures of it, it was a couple of years ago. Was a tack driver so I was pretty stoked. About to do again so will see how it goes this time
1 5 shot & a couple of 3

Attachment 270611Attachment 270610Attachment 270613Attachment 270612

A very precise rifle there! Was it a hunting rifle?

Originally Posted by Hunterdave

Quite surprised theres not much focus on seating depth here. Remember watching a podcast with eric cortina and jack nerry (i think his name was) one f class the other benchrest for team lapua. Talking about seating depth has a direct relation on group size, testing in 3thou increments. A example of this is when people buy factory ammo to test what there rifle likes that is the seating depth of the different ammo that determines the better groups.
I think his way of load development makes sense, first stage over chony, no target to distract you, find lowest es
Once powder charge found on to seating depth testing

@Hunterdave

The focus is on testing a conventional approach to load development - varying charge weights of the same powder. Do they actually produce different precision characteristics or velocity consistency (when measured properly), and does the conventional process actually work to identify this? The answer appears to be no to both.

The evidence available for the same questions for varying seating depth within the functional window also appears to be no - however if someone wants to test it meaningfully and determine whether or not this is true, I'm interested to see - and will update my position as information is available.

e.g. https://youtu.be/_h4iAiGYbwg?si=uEfJaoLj_D7HAjvv

However, it also has become apparent that "optimisation" approaches to load development are extremely inefficient, and a "requirements" approach gets you something functional a whole lot faster and with more confidence.