Ran another ladder still can’t seem to find a clear path forward

[StumpGrinder]

Both ways are commonly used. Because new barrels/guns are getting faster as they break-in, it seems like the ideal time to do the seating depth test and tweak. I haven't found the ideal seating depth to change at all with different powders or charges. If I can get half the equation done, it makes quick work of finding the right powder. Been more than a few times that I determined the powder was completely wrong with with less than a dozen shots. It also makes reading groups much easier.
Good luck.

Well, that makes sense. The seating depth is the relationship between the projectile and the barrel. However the accuracy node has to do with barrel harmonics. Which has more affect on that, seating depth or powder charge???

 

[L.Sherm]

Here's my philosophy for whatever its worth. You pick X powder with middle of the road charge and do seating depth test now you determine its not the right powder so you change does the seating depth stay the same? Its never worked out that way for me. Its always been powder, primer then seating depth in that order for me.

 

[StumpGrinder]

That's funny. I figured it was a joke about being a cowboy who drove a sedan. Just goes to show......something, I guess, not sure what.

I didn't know there was another Sedan in the country. I've been told that my home town, Sedan, Kansas was named for a place in France of the same name because some of the founders of my town were from France and our valley reminded them of a place there. I have know way to verify.

 

[smokey3]

Here's my philosophy for whatever its worth. You pick X powder with middle of the road charge and do seating depth test now you determine its not the right powder so you change does the seating depth stay the same? Its never worked out that way for me. Its always been powder, primer then seating depth in that order for me.

I have two loads using the powders that I had on hand when doing testing for a new 300 WM, IMR 4350 and H1000. I was breaking in the barrel so I chose some very old IMR 4350 that I"ve had since the mid eighties for break in and fire-forming my brass. The IMR shot lights out with Nosler 180 grain BT and AB bullets at 3.420" OAL and 70 grains. The H1000 shot really well at 79.3 grains, but was a very compressed load. The IMR 4350 was slightly tighter group but I do not think I could Compress the H1000 down to the same seating depth and ended up at about 3.56" OAL. They both shoot under .5" at a 100 yards and the H1000 shoots about 2.5" at 500 Yards, so I think with some powders you will often find good accuracy at different seating depths., using the same bullets. In essence a powder charge change and a seating depth change both cause barrel harmonics changes in your rifle. It is up to the individual to find the combinations that work best in their rifle and that is what most of us on here enjoy doing, it is a challenge sometimes, but part of reloading is the satisfaction of finding that perfect blend of components and that big smile on our faces when we do. BTW, I like checking the Nosler reloading data for the simple reason they list the most accurate powder tested, whether I use their bullets or not, the powder information is often spot on but we all know rifles respond differently depending on individual barrels and components chosen.

 

[066wally]

Do a seating depth run on the 8-1, 8-2, 8-3, and 8-4 load. That will clean right up.
View attachment 248932

Yeah, that'd be my load. Depends on your purpose for the rifle though.