My rifle is a 336 Rc made in 1954. It has the straight grip and ballard rifling . I think these rifle were some of the best made by Marlin. The bores are not over bored like the newer micro bored that might slug out to .360.
Mine shoots the 200 gr. lead cast bullet over Varget printing groups , not clusters at 100 yards.
So you may say that you never get your hands on this one as long as I am around.
I think if the bore is good you got your self a keeper, one of Marlins jewels.
And hope you have as much fun and pride with te gun as I have.
Good hunting. you bagged a great one.
Happy