Tufr, About your Marlin, first off let me ask you the year make of it. Marlin went through a pretty tough time about 2 years before the Rem takeover and then about 5 years after the takeover. It was a pretty big gamble on whether or not you would get a good shooting rifle. If your model falls within those years, I would suggest you take it to a good smith that has good experience with lever guns and have him check out the action as well as head spacing and barrel square. Also check out your crown with a Mic to make sure it is concentric. Just a tiny bit off and that will throw your groups to the wind. Another thing you can try since you reload, is try the leverevolution powder and the FTX bullets. I haven't tried the powder yet but I use both the 160gr .30 cal FTX for a couple of my .30-30's and the 265gr for one of my .444 Marlins. The other one doesn't like those FTX's a bit but loves the Interlock. (personality of a rifle, go figure) I do intend to try that LE powder as it is claimed to be about 150-200 fps faster.