Primer seating questions

[yorketransport]

So your saying because I'm running the 67.5 grains instead of the max load of 65.3 grs ( according to the Berger manual ) that's why the primers are loose ? Why would only 10 ( i didnt actually count them all ) of the 50 be like this ?
The rifle is shooting this load extremely well.
I have a new box of brass on the reloading table now, just wanted to use these 1 more time.

That's more than a little on the hot side by my standards.

Trying to get one more load out of those is false economy. A blown primer can cause pitting on the bolt face which is much more expensive to fix than buying a box of new brass.

Each case will react differently to the same load. It's also possible that there was something different (seating depth, charge weight, etc) about those 10 cases.
Andrew

[fastdam]

I have had new Winchester brass, with primer pocket tension variations.  I never measured the primers themselves before either...everything has tolerances.

[300rum]

I would start over with new brass too.  If that is the load the rifle likes then that is the one you should use, SAMMI is just a guide,not a rule.  Make sure that you know the signs of pressure.  When shooting that hot just know that brass life (and barrel life) is going to go down.