Brass length shortened after necking down?

[Gregor.Samsa]

I just FL sized once fired 6.5CM Peterson brass in a 6CM due to neck it down. The brass was annealed before sizing and then mandrel expanded afterwards. I did not measure the brass lengthy prior to doing any of this, I assumed it would need to be trimmed. I just measured the cartridges and they are measuring between 1.905”-1.907”. Book trim length is 1.910”. Is this usually the case (no pun intended lol)? Is this brass still ok to be used? Thanks

 

[Gregor.Samsa]

Forgot to mention shoulders were bumped 0.002”

 

[Shoots 700's]

do the sized cases chamber freely? I would shoot them

 

[spife7980]

Hard to tell without knowing what it was before. I wouldnt be concerned with coal as it basically means nothing so long as its not too long.
I would make sure your cases have adequate diameter clearance in the chamber. Sizing it down makes em thicker.

 

[Gregor.Samsa]

Yeah the cases chamber just fine. I thought it was odd they’d shorten.

 

[spife7980]

Yeah the cases chamber just fine. I thought it was odd they’d shorten.

I did not measure the brass lengthy prior to doing any of this, I assumed it would need to be trimmed.

You said yourself you dont know if they have shortened.

 

[Gregor.Samsa]

You said yourself you dont know if they have shortened.

this is true! I really should have measured first and made the assumption that the cases were longer. I cant see them being shorter than trim length though after one firing.

 

[ACard]

Once fired Peterson brass, I am pretty sure it did not shorten on you, mic one of the other cases as 6.5 CM and check the length. All my Peterson started out a few tenths short and took a few firings to lengthen.