I agree. Sectional density and bullet construction trump bullet weight as far as penetration is concerned.I believe the 160gr bullet (especially the longer Barnes) is about perfect in the 7mm RM caliber. Good ballistic coefficient and sectional density. A hunting acquaintance uses this bullet weight for elk and deer. But I believe what Rule303 is saying, is that when one goes up in caliber, a heavier bullet is needed to maintain good bullet BC and SD? As an example, I use 225gr bullets in my .338WM. 210gr might be OK, but 185gr bullets in that caliber, don’t have a good BC or SD? They probably would work OK, but I’ll stick with the 225gr with a great BC and SD. Just my 2 centavos?