.308 Comparator mystery...

[fla9-40]

Got a question to ask:

Was checking the lands on a new box of .308 Sierra 168gr HPBT MATCH
bullets mfg # 2200.
Was using the "start the bullet in the brass and closing the bolt on it method"

I was using brass fired from my rifle, Cleaned, checked length trimmed if needed,
and Neck sized.
I random picked 7 pieces of brass and 8 bullets.

This is the first 8 measurements with the Hornady Bullet Comparator:

2.299
2.296
2.294
2.295
2.298
2.298
2.294
2.295

Now the next 10 measurements:

NOTE: After the first measurement from this batch I Neck sized the brass before
each test. Again random brass matched up to random bullets:


2.313
2.314
2.308
2.310
2.295
2.301
2.304
2.314
2.296
2.312


Checked to see if calipers were zeroed each time.

Can someone shed some light on this, are the bullets from the last 10 being pulled from the brass
when I gingerly extract the round to measure???

Thanks for help on this!