I cannot speak to the JP's or GAP's and 6.5CM, but my brother has an SP-10 in 6.5 and it has been an absolute workhorse.
Ironically, I have been reading up on SCAR 20's in 6.5, and there have been quite a few reports of folks having feeding problems with Hornady's 140's.
What have you heard, scene or experienced from the Seekins rifles in 6.5?