6.5 Load Development Seating Depth Question Pls

[Brazo]

Hello all,

Newish reloader here. I have a seating depth question at the end and I wouldn't mind someone looking over my process and see if anything looks out of whack please.

I have some test loads put together to test powder charge OCW for a 6.5 Creedmoor hunting rifle and plan on the following:

143 Hornady ELD-X
Alpha LRP brass
CCI 200's
H4350 powder

All loads tested -.020" off the lands

Powder charges (5 shot groups of the following)

40
40.3
40.6
40.9
41.2
41.5
41.8

After seeing where the center of these loads print on the target and finding a flat spot and using that powder charge, I believe a seating depth test is next.

My question is, in what increments deeper do I test, and how big of a range to cover my bases?

I've seen recommendations for .003" deeper at a time (which seems really small movements to me but what do I know?)

I've also seen some say next try -.030", -.050", -.080, -.100.

Thank you for any help, I appreciate it!

 

[Supersubes]

.003 would be a monumental waste of time. .010-.020 would work. I do .010, and usually end up around .030-.050 off the lands.

 

[Gustav7]

Scott Satterlee was on a podcast this year with Modern Day Sniper @velayo_0317 ... He was talking about his experiments with seating depth and how he's been pushing his seating depth tests into the 100+ thou.

An example is he'd do 5 shot groups at:
.030" off
.050" off
.080" off
.100" off
.120" off

Then follow up the best of those with bullet seating depth node testing, so go 10 thou on either side of whatever works the best. When doing this you'll want to be looking at two things:
1.) Small Groups
2.) POI (same POI indicates similar barrel harmonics)

 

[Brazo]

Thank you guys, I appreciate it. Makes total sense.

 

[Gustav7]

Thank you guys, I appreciate it. Makes total sense.

Keep in mind that a large difference in bullet seating depth make change your pressure/velocity, so some minor adjustment may be needed there.