No, not in modern rifling, you ream a barrel to .275 then when you push or pull the button through the bore ends up .276" and the groove ends up .284", pretty standard rule is .008" from bore to groove today. In the old British and European guns with cut rifling the bore to groove diameter could be as much as .012" different, with the difference always (well almost) being to a smaller bore dia and the standard groove dia.
The Brits almost always designate calibers using the bore dia. instead of the groove or bullet dia. as the Europeans and NAs do, hence the 275 Rigby, the 303 Brit, the 404 Jeffries which is actually .423 groove but the Brits made the rifling deeper as the dia increased in some calibers, or they just lied because it didn't have the right ring to it. Then there are the exceptions like the 416 Rigby...........We here do the same to a certain degree, the 38 special, 44 spl and mag, 218 bee, 250 Sav, all have huge variances in the names but all share the standard bullet diameters with their more correctly named brethern, except the 44s which no one has ever been able to explain to my satisfaction, hell it's not even a 43 magnum, really. How does anyone get 44 from .429" and it was the 44-40 that started all this BS. That one loses me............