Re: OK I need help!
Very big NO NO --- I have been shooting the 338 or a variant of it for 20 years. Lapua brass is all I have ever used and the long story short is that when you change components even lot numbers you always have to check. This is why when I develop a load I have enough components for the life of the tube when I start load development. Before I started to compete and learn from my mentors I had the same thing happen to me that has happened to you! My rifle was a AI AWM in 338 and I was able to buy some once fired brass and did not think about any differences and I had sticky bolt lift and hard extraction.
In summary the load in the once fired Lapua brass had to come down by 2 grains of 7828 with a 250 SMK. I know this does not seem like much but it allowed the rifle to function and shot the same velocity and almost POI.
The Truth Is Not Always Good For Business!!