I recently purchased a Remington 1187 Premier at Walmart for 525.00. They were on clearance and I thought it was a steal. Got it home and gave it a through cleaning and found what I think is rust inside of the barrel. I really cleaned it and I can't tell for 100% sure but I think it is rust. My question is should I return the gun or keep it. Will this little bit of rust, if it turns out to be rust cause any problems with shooting? I'm not sure what to do because it was the last one they had and the rest of the gun is perfect. any advice?