I have not tried them again, and I have no intention of ever trying them again.

As I stated above, I continue to see this with other shooters on the range. When they have been able to give me any more than a blank look when I ask them what primer they are using, they have, IN EVERY CASE, said it was CCI 400.

I have not had a single slam fire using CCI #400's.  I have had a pierced primer or 2 using fast burning powders close to max load along with some very flat fired primers.  If i'm using the #400's I use a slower powder and under max load.  When I can I buy the #450's or Federals.

kwg

WEG, I asked because you seem sure that your loads are at the prescribed limits. I'm betting you have/were/are past them, even with magnums.

With my lots of components, 23.8gr H4895 under 77 SMKs in an RP case, and 24.5 gr Varget under H75s in an FC case was the highest I dared before piercing became the norm. Even then flattening was moderate and the craters were bold enough that I back down to 23.5gr and 24.0gr respectively to maintain safety and reliability.

If you push beyond book .223 data towards the ragged edge, yes, 400s will likely fail. At a comfortable max, my data is still 0.9 and 0.3gr above Hodgdon's max listings for .223. Maybe my dry molying gives a wee margin, but 400s aren't a boltface eating being unless one expects too much.

Lots of interesting experiences it’s good to know this, also seems like many have been from years of use with positive outcomes, and a small percentage of negative outcomes, I am feeling very confident of using these primers for my target practice loads.

If you won’t use them then I have a shipping address for you to send them to for disposable.

I run 25.3 grains H335 with all my 55 grain bullets. CCI 400's flatten and crater badly with that load but no piercing.

I used to use WSR primers exclusively when they came in the white box and were plated. When they quit plating them and shipped in blue boxes I had trouble with them flattening and piercing with the same loads I'd been using for several seasons of XTC competition.

Today I run BR4, #41 and Remington 7.5. Once I run out of BR4 and 41's I'm going all Remington 7.5 exclusively.

I've never had a single issue with CCI-400 in any AR platform. My typical plinking loads are 22 to 25 grains of WC-844 with 55gr bullets. (.223/5.56) cartridge.

Motor