Not a 7-375Ruger or 7 LRM, which I think use the same 375 Ruger parent case. I'm not all that familiar with the 7 LRM but after GW necks it down and they push the shoulder back on that 375 Ruger case, it's relatively close to what's in the picture.
A little hint but it likely won't be of any great value, this is NOT any kind of wildcat cartridge and the headstamp matches the case. It is not a necked down something and the case is as it comes from the manufacturer. Brass and or loaded ammo is available for this cartridge.
I'll say 180 bergers 175 eldx 168 bergers
You have two of the three correct. Not a 28 Nosler, the 28Nosler is a little bigger case capacity.
