I just bought my first rifle. It's a Marlin 1894 in .357Mag. I don't know much about it yet which is why I joined this (my first) forum. I'd like to know when it was manufactured. The serial # starts with 2010. I'd also like to know what micro-grove means, which is stamped into the barrel. It also has JM stamped into the barrel which I'm told is a good thing, but I don't know why yet. I would like to mount a scope to it but I also don't know much about them either. I'm not completely clueless, but obviously I need some help and advise.