something confusing happened last night..

i've been loading for a couple years now.. went down to the bench to load up some rounds for a range session today. of those rounds, i had a dozen 204 ruger rounds to load.

i keep all my brass sorted. stored in labeled plastic bags, sealed. i pulled out a bag of hornady brass, that's been shot a few times, that had already been tumbled, sized, trimmed, chamfered, and pockets cleaned. (that's my standard prep process for cases. then they get bagged and labeled "ready to load".)

i proceeded to prime and charge the dozen cases. then started seating the bullets. here's my question - of the 12 rounds, 7 were fine, but 5 had neck tension that was so loose, that the bullet would just about slip right into the case. i set those aside.

how does a case that has been sized have such loose neck tension? i didn't put the sizing die in and resize them - i will tonight, but i had 22-250 and 30-06 loads to get ready for the range today, and had to move on. has anyone ever experienced this before?

i don't feel i'm shooting an excessively hot round - 35 grain berger match, 25.5 grains h322, federal 205m primers.

by the way, its a year old RCBS 204 ruger die that i'm using. this particular load was for my CZ, with hornady brass. i have another 204 as well - single shot H&R. use varget and remington brass in that gun. and i've never had the problem with the remington brass. since the same die is being used for both, it leads me to suspect the CZ load or brass as the culprit? or maybe it was just my screw up somehow.

any advice would be appreciated.

If your expander ball is the correct size(about .001" to .0015" under bullet dia.) Then your brass has thin neck wall thickness. Neck wall thickness can thin from a few loading and working the brass. Or you sizing die is not sizing down enough.(not common) You need a good micrometer to measure all.

I have reloaded .338 WM and 30-06 Spring for years and never seen that with any
Brass
Bullet
Die (RCBS or Forster)

thinking about it, some of this brass had been loaded, then had the bullets pulled, and reloaded, without firing. however, i size everything - so even those rounds should have been re-sized.

i'll investigate further tonight.