I encountered the bearing surface situation with the first .243 load I ever constructed. I used the Hornady 100 grain round nose bullet and H4350. Just to be prudent, I usually start out a good bump below maximum and work my way up.
I didn't have any data for the 100 grain Hornady round nose, so I used load data for a 100 grain spitzer and backed down to 4 grains below maximum. The 100 grain Hornady round nose (now discontinued) was almost *all* bearing surface.
At 4 grains below maximum for 100 grain spitzers in the .243 with H4350, I was getting very flattened primers with the 100 grain round nose bullet.
I knew that the bearing surface of a bullet would affect pressures. Common sense should tell you that. But I was surprised that backing off what amounted to 10% below the maximum data for spitzers still wasn't enough to allow for the additional bearing surface of the 100 grain round nose bullet.
I'm not surprised that Hornady removed it from their offerings.
