Go to your local stores and look for both boxes of ammo on the shelves.
The way things have been with ammo for the last year or so, depending on the region/area that may or may not be a true representation these days
I know that this past Fall in my area any of the more common cartridges like the .270 were in short supply.
A similar comparison with handgun cartridges is that for a long time in my area you couldn't find a .380, or 9mm round to save yer life, but often the .40S&W's were available.