Initial Shoulder Forming and Post Firing Resizing

[Scalce]

I am a newbie when it comes to 300 Whisper-300/221-300 Fireball so I apologize for the basic questions.

I have a new barrel that I am forming brass for.

I also have a chamber gauge which has been a life saver.

I noticed that when forming LC brass I need to screw the die down about a 1/4 turn more than with some other headstamps.

My question is, do you guys sometimes have to over resize LC brass because of the shoulder issue and then after initial firing, you can back the die off for normal sizing more inline with commercial brass?

I know it is not the body of the cases as I have done some testing and it definately seems to be the shoulder making contact in the chamber gauge.

This is kind of a pain for trimming as I use a Possum Hollow and it indexes off the datum just like the Giraud so I have to adjust for die movement and brass type.

As much of a pain this has been, it is fun.

Thanks