Seating Depth Before Charge Weight For VLD?

[Winny94]

Im trying to work up a load for a Berger 7mm 180gr VLD Hunting, and ive found a few instances when the loader actually did the seating depth testing before any sort of charge weight test. Anyone here have experience doing that? Why do you consider that a better process? How do you decide the charge to shoot the depth test at?
I plan to shoot the method recommended by Berger for VLD bullets in a mag fed rifle, just cant seem to find when I should do that.
Load 24 rounds at the following CBTO

1. .010 off the lands (jump) 6 rounds
2. .050 off the lands (jump) 6 rounds
3. .090 off the lands (jump) 6 rounds
4. .130 off the lands (jump) 6 rounds

 

[dok7mm]

I usually run seating depth testing, early on, while forming brass and/or breaking in a barrel. At 100 yards, you'll get close, as conditions are better. I always follow up with seating testing @ 400, when brass has been fired twice and barrel is consistent, using my preferred load. Just confirming that the early test will hold up and if I may have to tweak it a bit.

 

[SealT5]

This photo is from Aug 2016. Range is between 100-150yds.

This was a new barrel properly broken in and I had performed a pressure test. I followed the Berger VLD suggestion and as promised it produced a group noticeably and repeatedly better than the others. If I remember right the sweet spot was between 20 & 60 thou jump.

With non VLD bullets I take the arbor press to the range and while breaking in/fireforming brass I look for the optimal seating depth. Later when brass in fully formed and I have a node selected I may play with things to see if I can improve accuracy Works for me

Joe S

 

[ShtrRdy]

There is a lot of good information in this thread, part of which is doing a seating depth test before powder charge weight testing. Read member Mikecr entries.
https://www.longrangehunting.com/threads/seating-depth-in-a-300-win-mag.225678/

 

[jweigel]

Unless you are shooting where it is pretty cool, doing TWO separate three day shooting groups of 3 rounds per depth looking for a repeatable trend is what I do. The better seating depths should repeat and because I almost always am shooting VLDs....I always do seating depth 1st. With standard VLDs not the hybrids....I generally see very obvious differences and they repeat. Some barrels/calibers ...the best is close to the lands (never closer then .010) and some are jumping as far as .070. I never assume or expect.....let the gun tell you.

This is way factory VLD loads like HSM work great in some guns and not in others. I even had a coworker that had a .5 MOA repeating group with factory HSM 168 in a factory Browning only to find HSM changed there brass which caused the new factory ammo to open up to 1.5 inch groups. He searched the country and found enough boxes of the old "good" stuff and it continues to shoot lights out.

jjw
ND

 

[L.Sherm]

When I start out with a new barrel and brass I'm mostly looking for FPS with a few powders and looking for tendencies like is it trying to group, vertical is there big ES differences has the barrel did its speed up thing. Then I do a ladder test. After that I pick what powder I think is the best and start working on powder charges to see where I hit pressure. When I'm settled on that I test different primers, then seating depth and finally neck tension in that order. All my ladder tests, primer, seating depth and neck tension is done at 500.