i'm not sure, but i think i remember hearing that pretty much all bushy's have a tight mag-well.  anyway, none of my USGI mags drop free (unless they're full).  it appears as if the tight spot on mine is the recess where the mag catch bump slides into.  i guess what i'm asking is what's the proper way to take care of this?  i'd rather fix the gun instead of countless mags, so can i just take a piece of fine sandpaper and massage that groove a little?

you might want to uncrew the mag catch a couple turns, press in on the mag catch button with a screwdriver, or a round until the other end clears the mag well, then unscew it a couple of turns,  that should help somewhat in releasing a empty mag. within time the areas in the mag well will wear out where it won't be that hard to insert or drop a mag. I wouldn't go sandpapering the inside of the mag well.

The Busmasters have a tight mag well compared to the Colts...

Usually one or two hits with a good file across the raised area of the mag cures the problem. Okay mags have a nice flat spot on the raised area. Centers seem to have a burr or higher area...