New Tikka and 6.5 CM Headspace

[Tim]

TL/DR: Once fired brass measures 1.558" base to shoulder. OK?

So, I have a new toy and not sure I understand the numbers I'm getting.

Here's what I'm working with
1. Brand new Tikka T3x Tac A1, exactly 60 rounds down the tube.
2. Brass is from Hornady Match, factory load 1x fired from this new Tikka.
3. Brass is untouched since being fired - has spent primer, is not tumbled, etc.

My Hornady Headspace comparator tells me that my headspace is 1.558". That's measured consistently across 10 cases.

1. In looking at the SAAMI specs, this 1.558" seems long? Best I can find is that 1.551" is max.
2. Am I supposed to deprime and tumble before measuring?
3. If you were me, would you resize back to minimum spec or just bump back .003" and still be over spec?

I'm not new to reloading per se, just new to actually being precise about it. Previously I just set my dies according to the manual and called it good.

 

[jmccracken1214]

Always deprime before measuring.

I size mine 2-3 thou less than how it comes out of the chamber. .002-.003

 

[Tim]

Always deprime before measuring.

I size mine 2-3 thou less than how it comes out of the chamber. .002-.003

That gets me in a catch-22, for now anyway, as my deprimer is also my NS die. New dies are on the plan for the next week or so when I have a minute to decide what I want to do.

 

[Slacker]

Get a Lee universal decapper.
Every handloader should have one.
Also a universal flare die.

 

[jmccracken1214]

That gets me in a catch-22, for now anyway, as my deprimer is also my NS die. New dies are on the plan for the next week or so when I have a minute to decide what I want to do.

I use a Redding deprimer, it has a small pin, so my small flash hole Lapua is good, but larger ones as well. I always deprime, wet tumble, line/size and clean again

 

[Tim]

I use a Redding deprimer, it has a small pin, so my small flash hole Lapua is good, but larger ones as well. I always deprime, wet tumble, line/size and clean again

my question about cleaning was specifically to do with getting the headspace measurement. Of course I clean brass before processing.

 

[jmccracken1214]

my question about cleaning was specifically to do with getting the headspace measurement. Of course I clean brass before processing.

Gotcha, you don’t have to clean for the measurement but definitely deprime before measuring headspace and coal