Thread: Loose primer pockets

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

Depends on what you call loose
If the primer stays in and you can't push one in with a thumb then is it loose???

Loose enough when the next shot shoots shit in your eyes and craters your bolt face

Thats whats happened or what you think will happen??

Whats the head expansion?

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.

I have had an issue with Winchester Magnum primers.They are blowing around the edges and cratering the case and also eating a ring around the bolt face.I have heard of several other people with the same problem but mainly large rifle. Not sure if its a batch problem or they have changed their design slightly. Im going to try federal Magnum primers.

That's what happened I bought 50 new brass and they were the same after 1 only warm firing, must be the chamber the reamer was a standard one from the guy at Paraparaumu , Cleland ?

Yip chamber is most likely baggy /poorly machined