My Marlin 1894 cowboy i picked up a couple weeks ago has a loose forearm. By that i mean the forarm and be moved back and forth (towards and away) from the action. How can i tighten this?

The forend hanger is a thin piece of sheet metal dovetailed into barrel. You can peen the dovetail to tighen it or epoxy it in. I just solder mine and have no more problems.

You might want to leave it just a bit loose, I think they shoot better that way, especially when the barrel gets hot. If it really bugs you, try putting some RTV silicone between the forearm and receiver. See McPhereson's "Accurizing The Factory Rifle"

Get a winchester! LOL. sorry couldn't help it!. Had a problem w/ my Winch. 94 trapper in 44 Mag, kept breaking the pin that held the mag tube in place cause of my hot loads. Replaced it w/ other than factory(went thru 2 of those factory pins(sucked)). No worries in the last 15 yrs. Shoot .44 Mag Heavy loads. NP. Good shooting.

I loosened mine on purpose to relieve pressure on the barrel to improve accuracy. It helped a little.