Jacket material, thickness and hardness, core hardness and bearing length of bullet against the barrel can all affect resistance to being driven down the bore. As can location of the crimp groove (how much case room the bullet takes up), if any. All of which can affect load data even assuming same bullet diameter.

If you're somewhere in the middle of the load data for a given bullet/caliber, it shouldn't make all that much difference. OTOH, if you're near the upper end of the load data it can make a big difference.

In Re: 2000 f/s-someone was making a 180 gr bullet for that velocity at one time. You might contact the various manufacturers for further info.