This debate has nothing to do with the effectiveness of Rugers 3/8" offering, as it's ballistics virtually are identical or even a touch better than the TRUE KING. My entire premise is that it will die off into oblivion for just this reason, it does nothing new. The fact that 5 years have now past without a single major ammo company jumping on the bandwagon to make ammo or brass available for it, tells us all what is in the future. The fact that only a couple low end makers have added this caliber to their line-ups is another telling feature as to the future of this dead cartridge.
Your research as to rifle company and reloading company offerings in this caliber show exactly what I've been saying, as far as loaded ammo companies....................it's even more telling.
Gatehouse has become "The Queen of Denial", where this cartridge is concerned, and as such is giving bad advice to others in hope of increasing sales so his stillborn baby doesn't get buried, quite yet. Now that Ruger has changed and put this cartridge into one of the ugliest platforms I've seen in many years, I think we can all say goodbye to the 375 Ruger, once and for all.
The 375 and up market is a very small market in the world of guns and hunters. It has been very well served with all the old proven, heavy game getters. All new entries into this market will usually fail because there is no niche for them to take hold. Look at the rash of 416s following the introduction of the 416 Rem, all of which are no longer available, except the original 416 Rigby, which didn't need improving. The 458 Lott has succeeded because the 458 Win did not live up to it's reported ballistics so a niche was there which needed a cartridge to fill and the Lott did it nicely. Add to these the old 404 Jeff, 450/400 NE, 500 NE, the 470 NE, the 375 H&H, 378 and 460 Wby for the extreme, and there just is no room for the 3/8" Ruger, 416 Ruger, 416 Rem or Wby, etc.