So I am currently on my 4th firing of Alpha 6GT brass.
The first firing shoulder depth was : 1.354
My fourth firing is now reading : 1.358
So with my die set to it’s original settings and no adjustments > instead of bumping my brass to 1.352… it’s pushing it to 1.355.
Using Hornady custom FL dies that i purchased from GAP.
I am very lost here.
Neither; you need to figure out what measurement is the correct size for your chamber. It may take several firings for brass to grow enough to fill the chamber before a shoulder bump is appropriate if the chamber is significantly larger than the new brass. Cortina should have a video somewhere about how to measure your brass relative to your chamber by taking out the firing pin and using the bolt.
Winning in the Wind also has a good video discussing this.
There is also some data there about annealing too much and how it can reduce the consistency of neck tension; probably every 4-5 firings at most depending on the amount of stretch you are getting for the brass to reach the full chamber length.
I guess the part that is new to me is the several firings before the brass properly fills the chamber.
I assumed it was good to go after the first initial firing.
I thought this exact same thing when I first got into this Hobby
The term “shoulder bump” is a disservice to people learning to reload, “clearance” is much better as what you’re doing is putting space between case and the chamber to allow cycling (and enough space for dust, condensation, dirt etc. to go in adverse conditions).