Just ran into something I've not encountered before. While working up loads for a new rifle/calibre combo ALL my handloads are at least 200-300 fps slower than what the book maximums indicate they should be. This with three seperate powders. Pretty sure its not the Chronograph or the rifle as the factory ammo is pretty much exactly as advertised. Now I can understand a few fps but 200-300 fps slower seems a bit excessive. Anyone ever encountered this before? Also no signs of pressure at the listed max so there is probably room for going over the book, but still. 
