Now that I think of it,the 6.5/300 Weatherby was a wildcat that had some notoriety back in the 70's(?),named then the 6.5 Wright-Hoyer or something like that. I remember an article in Rifle or Handloader about it back then. It was used for 1000 yard work as I recall.
I think it was the 6.5 Weathrby-Wright-Hoyer. Here is a quote from Sierra's second reloading manual, pg. 171.
"This cartridge was reportedly designed by Lt. Colonel Paul Wright(ret) of Silver City, New Mexico. It is sometimes called the 6.5X 300 Weatherby-Wright-Hoyer. "Hoyer" is a reference to Alex Hoyer, a Pennsylvania gunsmith, who built the first 6.5 X 300 for Colonel Wright and many of the rifles in this caliber used in the Pennsylvania 1000 yard bench rest matches. The design of this cartridge is simply the .300 Weatherby necked down to 6.5MM.the rifles chambered for it have a standard throat with no freebore."
They go on to list some UNTESTED, I repeat, UNTESTED loads of "Frank Weber who used the cartridge to set the 1000 yard record for ten shots at that time of 8.468 and perfect score of 50." No velocities recorded:
With H870, Fed 215, Sierra MK...82-84 grs. (Up to 86 grs for hunting)
With H570, Fed 215, Sierra MK...79-81 grs. (Up yo 83 grs for hunting)
