6mm GT chamber question

[StreetCred]

I've got a Tikka T3x action that I'm switching from 6.5CM to 6mm GT. Got the barrel installed. Go/No Go gauges verified the headspace is correct. I created a dummy round to find the jam/lands. I'm using brand new Alpha brass with Hornady 105gr BTHP bullets. The Hornady manual says COL for this should be 2.520". I'm getting 2.472". Measured 5 times with the same results.

Is this normal? Would factory ammo even fit in the chamber? Not new to reloading but I am new to installing new barrels. Just looking for a sanity check. Thanks!

 

[Wrench]

Sharpie a round, chamber it and see for yourself.

 

[StreetCred]

Sharpie a round, chamber it and see for yourself.

That's basically what I did. Didn't color the bullet. I loaded it to the books 2.520". After chambering the round it measured 2.472".