The 338 Snipe-Tac was developed in 2001 for extreme long-range hunting and target applications. The parent case is the 408 Chey-Tac necked down and shoulder improved to 35 degrees. H2O capacity is a whopping 165 grains and velocity is well over 3,000 fps.   

      Like the .458 SOCOM, the .338 Spectre cartridge was developed specifically for the AR-15 family of gas-operated, detachable-box magazine-fed firearms. The cartridge is intended to fill the gap between traditional pistol caliber cartridges and...

   The 338 Thumper is one of a new line of cartridges by Subsonic Hunter in Winter Park, Florida designed for hog hunting.

The 338 Whisper is part of a range of cartridges developed by JD Jones from SSK Industries. The parent case is the 7mm Bench Rest, necked up and fire-formed.      

     Interesting box that came out of Zimbabwe. The crest on the box bears resemblance to the SLADE Family Crest, but I have not found any other info on who Nimrod Cartridges were.  

   Prototype round by Winchester resembling a current factory load. the other one is the 264 Winchester prototype

   Developed around 2007, the 338 Xtreme (338 XT) is based on the 505 Gibbs case with a 35° shoulder.

   Developed by David Tooley, this is basically a 338 Lapua Improved

Wildcat based on the 284 WIN case. Designed by Hawaiian based gunsmith Mark Pinkston and manufactured by Kailua Custom Guns, Hawaii this was an attempt to offer a 338 cal rifle for carbines.      

The 338-378 KT was designed by Elmer Keith and Bob Thompson in the 1960's as a long range elk cartridge to be used with slower burning powders available at that time. They kept the Weatherby double radius shoulder but shortened the case 1/4" to better suit case...

   Cartridge by Ken Howell, based on the 30-06 case, but lengthened to 2.6" as opposed to 2.494" for the standard 30-06.

This is an “improved” version of the standard 35 Whelen with the shoulder moved forward by .050” and the shoulder about .020” wider. It is not the same as the Ackley version and the velocity/energy gain would be negligible over a standard .35 Whelen....

   Developed by Art Mashburn during the 40's or 50's. The rifle below was featured in Heritage Auctions LOT #32616 with the following notes: "...nickel plated floorplate engraved with a charging Grizzly bear in relief by Dan Clark. Nickel plated grip cap...

   Developed by Breil Jackson, the editor of Guns & Game magazine in Australia in 2001. It uses the 300 WSM case necked up to .35" with no other changes

Developed by Fred Wade of Wade's Gunroom, Phoenix AZ. Also known as the 35-338 Magnum, based on the 338 Win Mag case   

The 35 Whelen was introduced by Whelen on September 15th, 1923 in the American Rifleman in an article titled American Heavy Caliber Rifles for Large Game. Whelen reported that they were getting 2834 fps with a 200 grain bullet and 2635 fps with a 250 grain one....

   This is the 284 Win case necked up to .35. It gives basically the same ballistics as the 35 Whelen with about the same case capacity.

     PROVIDENCE. TOOL CO. - ON AN EVERLASTING CASE   I'm not sure about these 2 specimens. I anyone has any info on this please let me know    

Designed and launched by Winchester in 2019, the 350 Legend was developed for deer and hog hunting. From Guns & Ammo Magazine: In June 2014, Michigan’s Natural Resources Commission (NRC) approved the regulation to allow the limited use of certain rifles capable of...