Thread: Loose primer pockets

Originally Posted by nor-west

Shot 20 Winchester factory loads in the new built .264 win mag, when I was re-priming them there was hardly one that was firm most went in like they were undersized, I've been told to go to CCI mag primers as the are slightly larger?

Any reasons why the pockets would be loose after one factory load, headspace?

Thanks

It could be that your chamber is big in diameter & your brass is small, that will easily cause that.

As Spanners said how loose is loose ?

What do the case heads measure before & after firing ?

Primer pockets always loosen up to some extent when fired, especially for the first time.

Some primers are slightly bigger than others.