baltz526 wrote:Are you sure it was not Alliant data, BP copied under Alliant's Approval. After Alliant did the pressure testing?
I'll admit it could be, the point being though that particular load has never been updated by Alliant and again I don't trust BP's data especially data that is that old from them.
I'm not saying the load is unsafe and never have, quite a few of the 10 ga loads that Alliant has listed has been off in one way or another. When you posted up your getting higher velocities than listed and the very close velocity spreads your getting it points to the load being higher pressure than listed.
What we've found is once velocity spreads get very close with shotgun loads your very close to the point of diminishing returns, where your velocity is going to go down instead of up because of overpressure. Rifles and pistols work differently because they work at much higher pressures so velocity spreads that are only a few fps apart are not uncommon, shotguns are different.