Smokeless powder is not corrosive. BLACK powder residue is corrosive, but you would be very hard pressed to find a milsurp cartridge loaded with black powder.
It's the primer that can be corrosive. Many WWII and earlier US mil cartridges are corrosive (except .30 carbine) and most Berdan primed Warsaw Pact primers are corrosive.
To test your ammo, pull a bullet and dump the powder (in the lawn is fine, it is good for the grass, trust me), pound a couple of nails (8 or 10 penny) through a board (1 X 4), chamber the empty case and place the muzzle over one of the nails, FIRE.
If the primer is corrosive, the nail in question will be rusty in a day or two when left out in the elements.
Corrosive ammo is not an issue as long as you clean promptly with a solvent designed for corrosive ammo. HOT SOAPY WATER is the best and cheapest.