My brother bought his first Marlin recently. He got an older (1951) 336SC in 35 Remington. We took it out Sunday and tried out some older factory ammo. It was Winchester white box loaded with power points in 200gr. He has it equipped with a Lyman peep. I was not in on his clean-up job, but I suspect that he needs to clean some copper fouling out of it. We would shoot 5 rounds at a time. Each time loading in each individual round. We took our time and never let the barrel heat up. Temp. for Kansas was very moderate, and even the wind was calm. What I am saying, is that we had no excuses for the occasional wild flyer that would come every 3 to 5 shots. We had several rounds touching and then one wouldn't even be on paper. I am more consistant of a shot than that. Even with irons. Any ideas? I am going to inspect the bore a little closer next time. Wish that I had a bore scope. Thanks for any ideas.