In the firearms world, a scout rifle is a bolt-action (sometimes a lever-action) rifle intended to be a general purpose firearm capable of good usage in hunting and defense. The Wikipedia article does a decent job explaining the idea and its origins.
While there are a number of commercially-available bolt-action rifles intended to be (and sold as) scout rifles, I'm thinking of going with a lever-action rifle as my basis thanks to reading this Chuck Hawks article. Where I live, lever-action rifles chambered in .30-30 Winchester are very common. (Most of them are Marlin 336 models, but that's neither here nor there.) Therefore, acquisition is easy and won't be impeded by treasonous statutes. The ammunition is not regarded as "military" either, so stockpiling both the usual round-nosed offerings and Hornady's LeverEvolution cartridges with the polymer tips won't be hard.
The build in the Hawks article is mostly a matter of getting the rifle itself, followed by the aftermarket iron sights, the forward rail section, and then the scope. Everything else I can buy easily at the Fleet Farm store near the house, including the ammunition and a sock or case should I not want to hang it up or stick it in a safe.
Sootch here has a video that explains the hows and why behind this choice. While the rifle (a Marlin 336) is not scout-configured (the scope on a Scout Rifle has its mounting forward of the receiver, over the barrel; see the Hawks article for an example picture), everything else is on point.
If you live in a place where hunting rifles are allowed, and you're wanting to be prepared, consider setting yourself up with a Scout Rifle- either purpose-built or taking a hunting or surplus rifle and making the changes needed. Remember: bolt-action or lever-action, in a potent caliber that is easily gotten with minimal or no official scrutiny, and sufficiently affordable that you can practice on a regular basis. I'm with Hawks in the opinion of preferring "hunting" over "military" chamberings, but if you do go with one that's easily gotten.
(Note: For this reason, I do consider the 7.62x39 cartridge an acceptable "military" cartridge despite it not being a full-powered rifle cartridge, and therefore consider the CZ 527 Carbine in that caliber another acceptable basis for a Scout Rifle despite the lack of magazines with a capacity of 10 or more rounds.)
So, if you're in a position to consider doing so, consider having a Scout Rifle in your inventory. If you have only one rifle, make it a Scout and forget the rest.