[Flyn'dutchman]

I have a similar problem created by shoving Cheddite primers in Rem hulls. It expands the brass to where it won't fit in my Beretta O/U chambers. That gun requires sizing with a collet die any time. I have resorted to taking the deprime punch out of my Sizemaster and running them through the collet after priming. It's a pain so I quit using the Cheddites in the Rem hulls. Even drilling out the plastic didn't help. Not sure how safe, but sometimes "desperate things call for desperate measures".

 

[Flyn'dutchman]

The offending Cheddite primers are the new lots ones. I can't tell that they are different from the ones I have from ten years ago. Fiocchi and Rios make it even worse.

 

[Flyn'dutchman]

Wish it wasn't so but by the time I ram them in hard enough to make them flush the metal has expanded enough they will not chamber without running through the collet again. Maybe my reprimer punch is over sized. I don't like Rem hulls because the crimps burn off in 3-4 loadings but I was given about 500 so I am making the work with other primers. Cheddite primers are larger in diameter than Win. I have measured them, so have others. The new ones even stay tight in my previously primed Fiocchi hulls. Win 209 won't.

 

[Flyn'dutchman]

410 is only on I have any trouble with. 12, 20, and 28 have more plastic or paper around the primer to absorb the size without bulging the metal. Glad you got them sized down with the collet.