Lee -

I tried the 44 (.430) - 300 XTP's because of the stated (by Hornady) BC at .245 and SD of .21 in combination with the 300 grain weight.

The Speer site shows the .452 - 300's at BC of .233 and SD of .21.

Hornady show the 10MM-200's at BC of .199 with SD .179.

Where did you find the Speer BC of .269 for the 300's? (I'm certain I've missed something here)