Primer pockets
 

Has anyone experienced primer pocket expansion from shells loaded to higher than normal pressures? I was given a few hundred ( once fired empties ? ), and have found that I can push my Federal 209's into the primer pocket with just finger pressure, and some of them can actually be taken out again with my fingernail. I've also noticed that some of these empties have pierced primers, but look new in all other aspects.

What brand hull ?

or were they once reloaded with a larger primer - Fiocchi primers are a bit larger than the normal 209

so - their hulls have a larger pocket and i would expect reloading with their primers would stretch the pocket

not sure about the other (i use WW209 except for Fiocchi hulls)- but I would expect size variations between brands are not rare

European shotgun primers are slightly tapered.

Winchester primers have a reduced diameter straight section at the lead which acts as a lead-in and positions the primer in a readied (perpendicular) position prior to the action to press the primer into the pocket. This requires a little more attention to detail relative to the assembly sequence in that the act of seating (pressing) should be done in as straight up & down action as is possible.

The European design is one that allows the pressing action to be slightly off center and is reliant upon the taper to align the primer properly once seated.

Just two different ways to skin the cat that results in deformation of a primer pocket making interchangability a not so feasible proposition.
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This ignores the possibility of blowback and slightly large chambers.

..oops, just noticed that you cited Federal 209's - it's likely they resemble Winchester but I can't say with certainty.

Federal 209s run just a bit "fatter" than Winchester. If you really want to fit a loose primer pocket, try Cheddite primers. They're so oversize I won't use them. Then again, they are made in France...

Sorry, Cheddite 209 primers are the same as Win, Fed, Rem. A Fiocchi, Rio and some Cheddite primers are .004 larger in diameter. I believe the foreign hulls may be larger from this ad from BPI, but not sure.
Universal Primer Pocket Conditioner 10ga - .410
•The only primer pocket conditioner that fits all gauges
•Resizes loose primer pockets
•Great for Fiocchi, Rio & Cheddite hulls
•Saves money by fixing hulls
•Made in USA

I no doubt have a brick of Cheddites that are at least .004 oversize...

I reload Rio hulls and you definitely have to use the larger European primers as US primers just about fall out. The most interesting primer pocket issue I've encountered was trying to use Winchester primers in Rem STS hulls. When they form the brass and plastic together it creates a sort of diaphragm of plastic at the end of the primer hole. The Remington primers have a rounded nose that allows them to fit just fine; Winchesters with their squarish nose get pushed back out a bit. Took a while to figure that one out. You have to take a reamer and remove the offending plastic from each hull if you want to use Win primers.

I've used probably more than 50,000 Cheddites with the occasional Win. primer and have never had a problem. Just my experience changing from Cheddite to Win. Just measured both of them and they were the same - .244 . Richard, I only found that problem with Rem STS 28ga shells. I used a number drill, forget now which one it was. With the STS 12ga hulls I haven't ever had that problem - maybe I'm lucky.