They will not seat below flush with any brass I use commercial or military.Federals and Winchesters do seat below flush.The Winchester primers are a bit shorter than the CCI,but the Federals are not.If I uniform the pocket they will seat flush.I can't see uniforming all the pockets.I run them through a Dillon 550.I am afraid of slam fires.Has anyone had this problem with CCI`s besides me?Thanks ahead ,Huntz

Never had that problem and I've used all the CCIs. Interesting.

All I use are CCI 450's and never had a problem in military or Winchester brass. Sounds like you have brass issues.

Never had that problem. Have you measured the depth of the primers and compared them to any other small rifle primers?

Are the primer pockets completely clean of carbon before you try to seat the primers?

Ed

Well yeah if there is a problem you have to do whatever is necessary to get it right.

Primers need to be seated at least .001 below flush to be right.

Do you have a digital or dial calipers.

You can measure primer pocket depth, primer height and primer seating depth.

It's one of my most often used tools.

You don't want to be feeding a semi auto ammo with high primers.

Sometimes tolerances/imperfections stack, then you have to change something.

I've had brass having an excessive radius in the transition from the wall to the floor of the primer pocket.

I've had brass that had too shallow pockets.

I've also had primers that were tall. These were Remington 9 1/2 that required the primer pockets to be cut .001" deeper than the usual max depth to reliably allow proper seating.

I measured the "height" of a bunch of primers a couple years ago, and like almost anything in handloading, different lots will vary. However, even the shortest of three lots of CCI 450's on hand was taller than many other SR primers--though not as tall as the Remington 7-1/2's measured at the same time.

Also, 450's have heavier cups than Federal or Winchester SR primers, so won't "crush" as much when seated.

I noticed with the Federals and Winchester primers have a slight give after hitting bottom.There is no give on the CCI`s after seating so I think not crushing is the key to this problem.Thanks for the input and since I bought 5,000 of these primers I will have uniform the pocket so they work.Huntz

Do you uniform by hand, or use electric power? Redding offers a power-screwdriver adapter for its primer pocket uniformers that makes everything go a lot quicker. I try to avoid uniforming primer pockets if at all possible, but sometimes....

Similarly I just chuck the Sinclair tools right in the drill.

I have one of the RCBS electric ones.

I uniform all brass before the first reload. Sometimes the pockets are a bit round at the corners.
Most don't really need it, but as long as I'm checking for the bad ones, I just do them all.