Those are sweet little rigs for sure. I looked at one in 270WIN this spring but my cash was being saved for a spotting scope so I had to pass. It was excellent shape for just $700.
The 154gr Interbonds are shooting very nicely in my rifle using H414 as and IMR4350 being a close second, although not quite as fast velocity wise.
CCI 250 primer.
I am sure this combo will shoot under MOA all day long if I get a decent trigger put in, right now it is grim. Othere than that, it is my current go to rifle.
Enjoy your little gem and take good care of your 275 Rigby!
Noel