I don't have any really modern rifles so maybe I'm not well placed to offer an informed opinion but in my experience, true sub-MOA rifles are far less common than some would have us believe. In fact, (and maybe this says something about my shooting) I don't think I've ever owned a rifle that could be relied on to shoot under an inch "all day long" (as they say) or for that matter, deliver consistent sub-MOA groups on any given day of the year.

You have a rifle that shoots 140 grainers (of one sort or another) under an inch. You are nevertheless of the opinion that you've been short changed because it won't deliver the same level of accuracy across the full spectrum of .270 bullets. Again, I don't think I've ever encountered a rifle that will shoot anything I care to run through the mag into sub-MOA clusters. I mean, I hear about these rifles on the internet but I have never owned one. Again, maybe that says something about me. And I have to say, at this point we haven't even got to the problems I experience when shooting from a bench trying to coordinate my breathing and heart beat to the extent necessary to produce those tiny little groups as a matter of course at 100+ meters distant.

You have a wispy little high-power rifle that delivers a mid-range bullet weight into groups of less than one MOA. With a bit of perseverance and experimentation (there are lots of different bullets and powders out there) you may find another combo that also shoots under an inch - if you're lucky. If it were me, I think I'd be inclined to stick with the rifle for a while longer before ditching the thing and venturing into the unknown.