Wes Deams, took 3rd place prone at the Wyoming Midrange championships yesterday shooting 2f Eynsford in his 45-70, I believe he shot a 100x5 at 200. His final score was 264 x7 , shot from prone, especially when the conditions that were interesting to say the least, and shooting with a spotter who he had never met until they got paired up that morning... Speaks quite well of both the shooter and the load he uses.
There are quite a few folks out there shooting the stuff, so it's just a matter of time...