You're between rock and hard place. Rather than gamble on a rifle that you already have low confidence in, get another right now. I think the Ruger RSMs are likely the best pick of the production litter, and are quite likely to work and keep working. You will likely make a deal w/ a reputable dealer on phone, pay by card, have it next day shipped to your dealer.
Then mount your scope securely, and go shoot a bunch in the remaining two weeks before your trip.
