I have a Remington 700 in 270 that I've had for over 30 years. Over that time I experimented with numerous loads - powder, bullets, primers, etc. But I always come back to my original load of 55 gr of IMR4350 and 130 Nosler Ballistic tip bullets and CCI200 primers. This rifle just loves this load and the Lee factory crimp die make it shoot it even better. But, it hates 140 and 150 gr bullets.
IMO the key to accuracy is consistancy. I FL resize all my cases (neck sizing would probably be better), Trim each time to ensure case mouths are squareand cases are the same length,weigh each powder chargeand factory crimp.
I can't imagine a 270 shooting 2" groups without something being wrong either with the load you are using or some other issue with your rifle. Also, I never had any luck with the SST bullets in my 270 or any of my 7mms.