Save your money.
Get a Tavor.
Stack up ammo, water, food, medicine and antibiotics, and warm clothes.
Hope for the best, although if you have no military training you might not survive long fighting a russian invasion, unless you team up with the canadian forces, which would consider you more a liability than anything... Maybe read a few books on guerilla warfare, there is a good one written by a german african officer during ww1.
Works great for: russian invasions, zombie apocalypse, yellowstone volcano eruptions, falling skies alien invasions, massive earthquakes, ice storms, sharnados, katrina huricanes, etc.
Doesnt work great for: surviving nuclear war, fighting tanks, fighting drones, fighting artillerie, etc.