I haven't bought many genuinely new rifles lately, but new or used, I'll take it out of the stock and give the exterior metal surfaces a wipe down with a good CLP before sticking it into its knitted silicone sleeve for storage.
This is especially important with older used rifles -- before shooting you should find out what's happened under the stock line.
A couple years ago I bought a pair of antique German hunting rifles that turned out to have moderate-to-severe pitting in a few places under the forend, where I suspect blood had seeped in between the stock and barrel. I had to DQ one as a wall-hanger because of deep pits in the chamber area.
You can learn other things with the stock removed. My 'new' FN 1924 Mexican Mauser held a happy surprise in this respect: under the stock and handguard its barrel still wore a virtually unblemished factory blue finish, and displayed a set of proof marks matching those on the receiver, thus confirming originality. It was also apparent that the receiver was still in the white as manufactured rather than just having a worn reblue job.