well, your not the only person to have forgot about ammo and washed it
I know I have doen it myself over the yrs, mostly 22 rim fire ammo however

that said
I woudn't chance using it on a live animal
the risks are NOT worth the possible bad outcome of a hang fire or just not up top velocity's it should have


having 3 known good rounds might be more than enough, but I also wouldn't feel good going after a bear with just 3 rounds, things happen fast when hunting
a miss or two isn't impossible and happens more often than many might think
and having a wounded bear with no way to finish it off wouln;t be fair to the bear at all!


I believe last year even you missed with first shot, NO bash, just saying
what happens if you miss 2 times or wound bear and then miss trying to hit it on the run,
ammo goes fast when excited for a LOT of hunters

part of being an ethical hunter is knowing you have the means to kill your game animal,
save up, buy more ammo before going hunting would be my suggestion

and heck, more shooting time doesn't wound like a bad idea either for newer hunters, it helps them do better when the moment of truth comes, as many things in life are memory activated reflexes, the more you shoot, the better you get at it! which leads to less misses, faster kills, less tracking o game! win win win
minus costs of ammo!