not really, Yup I messed up on the first example, they are slightly different, but the .300WM and the .308 Win, both use a .308 calibre bullet, as do the .17 HMR and the .17 HM2 a better 6.5mm example would be the 6.5x55 swede, 6.5 grendel or 6.5 creedmoor, or for 7mm, 7x57, 7mm-08 or 7mm Rem Mag or even the 7mm rem ultra mag (you get the idea) , these rounds are very different, more different from each other than the .17 HMR and .17 HM2 are from each other, but I was just trying to demonstrate the principle, yes, albeit by exaggerating
DB
long and the short of the thread, I think