MalH is right on the money. I just got through shooting some various loads through my .223 Rem. VS. I was shooting the same weight bullets, but some of them were Blitzkings, some V-Max, some Ballistic Tips. They all had different points of impact, not just in elevation, but also in windage.
You simply have to zero your scope for whatever round you're going to depend on.
BTW, my Glock21, shooting .400 Cor-Bon, shoots significantly higher and flatter than when I'm shooting .45. I just have to adjust my sight picture to compensate. (Also shoots a little to the left with the .400 Cor-Bon.)
Shoot to kill; they'll stop when they're dead!