Why would you want to put a Tactical rifle Chassis on a hunting rifle?
Please don't take me the wrong way,but you seem to be lost as to what your trying to accomplish with any firearm. You talk about wanting to shoot long range,and then go buy a hunting rifle (Remington ADL),then you ask about changing it to a caliber that there's no way to do so- i.e. 300WM/338LM. You are wanting to CHEAP out on the price of a good rifle,and then you go spend your money on a rifle that would take 3 times as much money to turn into a decent target rifle instead of just going out and buying one that will do it out of the box.
And,you have yet even mentioned putting optics on your wannabe long range rifle.
Here's an idea-Don't shoot the ADL,and take it back to the shop you bought it from. Have them order you a Remington 700 mil-spec 5R in either 308 or 300WM since you seem to like Remington's. Then you'll have a great shooting long range rifle right out of the box. Wait until you can afford some decent glass,rings,rail for it,then buy them and either install them yourself or pay someone to do it. For around $2000,you will have a great rifle/scope set up,and it will shoot very accurate at whatever range you want to shoot at with you doing the shooting part.
You will spend over $2000 trying to transform that ADL into the rifle that I think you are wanting in your head,and you can get that rifle already to go in the mil-spec 5R.