I have a Marlin 22 mag that I never had a problem with till one day I cleaned in. I have cleaned it in the past and it never went off sight. This last time I cleaned it and went out a couple weeks ago and shot at a opossum and missed it. I shot the gun the next day and I could not get a group. I removed the bolt and looked down the barrel and it was filthy. I cleaned it again and tried to re-sight it in and yet again the first shot was high and every one after was dropping. After 3 shots I removed the bolt again and it was horribly filthy again. Could I possibly had some bad bullets? Or th It was the last 15 of 50 that this suddenly started to happen. The bullets are the Remington 33gr. accutip-v bullets. Any thoughts?