RST Shells
 

I've finally getting settled in the new home and getting my reloading equipment in place. Hence it's been three years since I've loaded my 16 & 12 gauge RST hulls. I've got Hornady 366 presses for both 16 & 12. Here's my question:
I had usually high number of the hulls separate, case head and shot column. I've taken all previous steps in the reloading process and all of these shells it's first or second reload. Are any of you experiencing this same issue?

RST separation
 

New first time fired had about a third of two boxes separate about four years ago. Didn’t reload any of them.

If it happens with reloads, it could be a large chamber. Stretching and resizing can cause the molded in hull to separate from the brass head. Not common really, but does happen. The only shells I have ever encountered do this regularly were the Winchester AA of 1970's vintage. Separations were common with then, especially with slide action shotguns. Caused a real problem around trap fields at the time. Everybody on the line carried a wad knocker in their pocket to drop on the hull to get it out of the chamber.

I have avoided AA since then due to the experience. While I was later shooting a lot of sporting, I gravitated to Activ for a long time. Some people didn't but I loved the all plastic hull. No separations and they seemed to me to be extremely strong, with no rim problems and their capacity seemed to give moderate pressures. If memory serves, I never resized and they worked great. Best thing was that they had some really different types of loads. I still have a few boxes of their spreader loads. I think they actually started that trend before some of the specialty brands.

I’ve had that happen with Federal Papers, after several reloads, especially with an ejector gun. The brass base separated from the paper tube, flew 5 feet. I pulled out the tube with small players I keep in my gun cart for just such instances. Never had that happen with plastic hulls and I reload RSTs, till they fail to crimp.

I never had RST plastic hulls (Cheddite) separate while reloading. I have had 4 hulls extract the head off the hull body the past two years at the Spring Southern. If I remember correctly they were all on 16g shells.

Precisely what happened to me recently, except it was a Fiocchi 28ga hull. I do know one of my guns has a larger chamber, because I have to run them thru the sizer before they will loosely fit into the turret of the 9000. That hull may have been reloaded several times.