I have been using the same brass for my 300 WM for about 4 years and with this load I'm using Berger 185 VLD's. So I got some new brass. I also ran out of my H1000 and had to get a new lot. I loaded the load I had developed with the new powder in both the old brass and the new brass. Here is my ave. velosity differences. Old cases and old powder = 2933; Old cases new powder = 2898 ; New cases new powder = 2882. Is this normal to have that kind of a change when you change lots of either powder or brass or both?