Rio .410 blow

[pacrat]

Yes the barrel is clear, shot different shells after without problem, and yes it is chambered in 3" .410 at least for the last 40+ years, can't remember haha. As for the blown primer sorry ment to say punctured if you look in the center you will see a small hole and gsr, not much gsr but it's there and not all the primers punctured and not all are as bad there speratic. I should just take apart a couple shells to see if there is a variance. That was a good idea about the over all length of the shell

Yes I noticed the puncture in the RIO primer. Which also lead me to believe due to the difference in fired primer appearances. That the RIO primers are made with a thinner/softer cup than the Win. And a hotter powder charge.

Some primer manufacturers use thinner/softer cups than others. Federal is known for thinner/softer more sensitive primers. That is their selling point with target pistoleros who use much lightened striker and hammer springs.

The primer extruding farther into the FP hole indicates hotter charge. Along with the blown/melted crimp. And the cup extruding "farther" into the FP hole stretched the cup to the point that the FP punctured it where it is thinnest.

IMO, thin/soft primer cups, and hot charge combined, explain the symptoms your hulls exhibit. Shootable? Yes. Reloadable? Nope.

JM2c