Seating depth for shorter bullets

[Tac-O]

I just finished reading this fantastic article. https://precisionrifleblog.com/2020/03/29/bullet-jump-load-development/ It appears that the same conclusions can also be applied to other long bullets (see follow up article).

I'm wondering if anyone has applied this test to shorter bullets... For example flat base bullets like the 30 Cal 180gr nosler partition.

 

[Mikecr]

You do full seating testing to find optimum cartridge-base-to-ogive (CBTO). As long as the different bullet has the same ogive radius, and you set it to same CBTO, it is still optimum. This, regardless of bullet bearing length seated inside necks.
If the lighter bullet nose is of different shape, then start over with new full seating testing.

 

[Tac-O]

I guess my question was pointed more towards has anybody done this test with a more rounded bullet nose to see if the sweet spot for bullet jump is much larger than the usual 0.010 or 0.020 people try to achieve. The bullets in that study all had long sleek noses, right? They all preferred somewhere between 0.050 to 0.080 jump.

 

[Mikecr]

So when you say 'sweet spot' are you talking about where best is, or window width for it?

 

[Tac-O]

Window width. The widest range of seating depths that share the same vertical dispersion so that there's no need to change it often.