Corrosive ammo does not damage firearms .
I have shot a lot of corrosive surplus ammo ( to be safe , I consider all foreign surplus ammo corrosive ) .
Here is the deal . Clean the gun PROPERLY before the sun goes down . That way the corrosive salts do not have time to start corroding the metal .
PROPERLY ? There are lots of methods that work .
Hot soapy watter . Windex with Ammonia . WWII GI bore cleaner is said to work .
I use Shooters Choice Copper Remover Bore Cleaner ( any of the copper removers that smell of ammonia will work ) . I clean untill I no longer get blue green stain on the patches , or until I get tired .
I then use a few patches wet with Hoppies # 9 , to kill the ammonia . This leaves the bore wet with Hoppies . I close the bolt and stick a wet Hoppies patch part way in the muzzle .
I repeat this process each nite until I no longer get blue green patches , with the Shooters Choice .
One cycle of this is probably enough to kill the salt . But I also want to remove the copper .
You are correct , if you shoot cast bullets , current production American non-corrosive primers and smokeless powder , you avoid most of this .
And it takes a long time to wear out a barrel with lead bullets . And lead bullets loads usually use less powder , less fire to burn out the chamber throat .
Lastly , if you have to clean from the muzzle , be kind , use a guide on the cleaning rod .
God bless
Wyr