i have built a couple 260s in the past, but could not get the accuracy or power to keep up with my 7mmRemMags.
That's too bad. Anything I point my 260 Encore at falls over dead. With cheap 139gr PMC bullets, cheap CCI military primers and cheap surplus IMR 7383 powder in Win 243 cases necked up - shoots 5 shots into .6". I do feel your pain though, as my DPMS 260 likes nothing I have fed it so far.
thanks for the kind words, tomk