Shoulder bump question

[NJRaised]

Hey guys, I am soon to be a new reloader. I have done a ton of research, but I have a question that I can’t seem to find answer to….

I plan on using lapua brass (223 rem). I am not a super high volume shooter, so I’m planning on using better brass and components.

Is it advisable to measure a once fired case from my rifle, and then shoulder bump (fl resize) new lapua brass to 2 thousandths under that? Some resources are saying no, some are saying yes.

I realize I can buy lapua ammo, shoot it, measure it, and then fl resize it with a .002” shoulder bump. But for new brass, is it advisable to bump it back to .002” under my headspace length?

This ammo is only for one rifle, a bighorn origin 223 with proof barrel.

Thank you.

 

[padom]

You won't need to bump a shoulder back on virgin brass to match fired case headspace....that fired case has expanded.....only thing I do with new lapua is run a mandrel in the neck then load and shoot it.....bump that shoulder back 0.002 after you firing it the first time

 

[NJRaised]

Ok that makes sense.

Again, I am new to this. I am very mechanically inclined, but this is a new subject to me, and somewhat intimidating.

 

[918v]

Generally new brass should be .002” short if the chamber is set up right. Some chambers are set up short and the bolt face will drag slightly on the case when rotating to close. There is nothing wrong with bumping the shoulders on those cases to make that feeling disappear but it isn’t necessary.

 

[RegionRat]

And keep in mind it often takes more than one firing cycle to get brass to fully expand to the chamber.

Take a few pieces though a learning experience where you neck size them and cycle them till you feel the onset of a tight bolt closure. Measure on every cycle and take notes. When you get to where the brass is tight in the chamber, that is the baseline from where you will bump.