Relationship between accuracy, BHN and pressure
Cast bullets must be harder as velocity increases, else leading. Kinda.
Is has been written that there is a mathematical relationship between accuracy, BHN, and pressure. This has been disproved several times. (“CAST BULLETS FOR BEGINNER AND EXPERT”, Third Edition, Appendix, 3.3 BULLET HARDNESS, CHAMBER PRESSURE AND ACCURACY).
The myth lingers on. And even if it were true, we cannot, at home, measure either pressure or BHN with any accuracy. I hope to hear from Ed Harris on this; he and W. Davis authored the seminal article.