The 8ga rim about .170" smaller than NEF barrel,
Important is that the base is about .280" smaller
so it has good strength.They use good steel in NEF.

It took a few tries, but I got a 8ga resizer working
perfect. And a tool I use on my case lathe smooths
the transition so cases don't hang up when extracting
even with heavy loads.With REM cases I fire about
four times without having to resize.

A switch barrel auto we are testing 3.5" 12ga
smoothbore USS-S slugs, with hopped up loads.
About as accurate as the other guns here. Also
I'm getting the auto set up in my 585 HE long
case.585 HE long case shown in the port.
Switching barrels only takes minutes. This 12ga
barrel about as heavy as the 210 Savage barrel.
It is originally a 3.5" 12ga autoloader I've reworked
the stroke and have a barrel extension coming to add
585 28" barrel. Gun is weighted, thick double pad.
We are going to see how mild 585 HE loads of
9,000 ft lbs work in autoloader.Ed