I have begun working with a 7mm Weatherby in a Mark V action and have come up with an accurate load off the bench, but had an experience today that has me a little concerned.
I took said load out to chronograph it so I could get my CDS cap from Leupold ordered and I ran three over the screens with my chosen load with no problems other than a little more deviation than I would like to see.
Next I decided to run a load .5 grains lighter through the screens. It booked 3,127 when the average of the other three was 3,020 and it was as close to a case head separation as you can get without actually separating.
I got to thinking about cause and effect and here is what I know. All of my brass is Weatherby brand and properly stamped to the caliber. What I don't know is how many lots of brass might be mixed in together, and how old some of it might be. I got some of my brass from a brother-in-law that might be pretty old (and I think I can now safely assume reloaded a few times).
I know how to check for an imminent case head separation with a paper clip straightened out, so I can filter through those for scrap, but am concerned about the good brass being different capacities after what happened today.
Best way to sort...weight, capacity, other?????
Anything else I should be looking at???
Thanks for you help in advance.
Given that, you're wasting your time and components.
Get a new batch of brass and keep it segregated into sub-batches each with its own, known work history.
