Nice antelope! While I am impressed with the 6mm BR, I think it is too powerful for coyotes, foxes, or bobcat. I guess I am interested in the Texas version of the .375 H&H: something that is not too powerful for small game like coyote, fox, beaver, bobcat, turkey, and javelina but adequate for medium and big game like deer, pronghorn and hogs. The .243 is too powerful for the small game stuff and personally, I think it is a bit too small for the big hogs and way too powerful for the meat hogs. A round like one of the little 6mms would be adequate enough with shot placement on big game but not too powerful for the small stuff.
The best quality of the little 6's is their ability to be chambered in slim, petite repeating rifles.