I have a 4 weight glass rod form ages past... I can cast non wind resistant flies out to blue gills to the backing if I want to on it, but I couldn't get a #10 woolly bugger past the shore without it snagging me or something close to me.... The action is jsut too slow, I'm not atht good of a castr ( though I out cast everyone with a dryfly on teh same flipping rod) or something in the formula is not right.

I say test it out and see what you can do.