More 223 OAL and accuracy

[Lilswede1]

Gun is a 223 CZ 527 Bolt Action.
I buy bullets one box (100) at a time from several different sources and have narrowed it down to either 50 gr. Hornday VMax or 50 gr. Sierra Blitzking as the best round for varmit shooting in that gun.
Just opened a new box of Vmax and loaded up 20 at an OAL of 2.280" which is the length that shoots best from that gun.
I chambered a round and it felt tight. Pulled it out and could see land marks on the bullet.
I chambered a round loaded previously at the same OAL and it was fine.
Then I measured a bullet from the NEW box of VMax with a Hornday OAL gauge.
It measured 2.250". My records show that the same measurement from the OLD box of Vmax was 2.300"
Regretfully I had destroyed the old box and did not record the "batch" number.
When I compared bullets from the new and old boxes with a magnifying glass I could see a difference in the configuation of the oglive - the bullets from the new box have a very diffinite slope as opposed to the gentle slope of the older bullets.
I reset my seating die for the new bullets to allow for .020" of freebore which is where this gun seems to shoot best.
Anyone else having this experience?
I keep finding out more and more and knowing less and less.
Is it a common thing to find .050" difference in the same bullet from the same mfg. but a different batch number?

[arizona98tj]

I certainly wouldn't expect to find that kind of difference between the "same" two boxes of bullets. That would be disappointing for sure.

Obviously, it did happen. One more thing to add to my list of things to check when reloading.