Some progress has been made. I applied ink to the rear of the forend iron and opened and closed the gun a few times. (The top lever seems to move with a normal amount of force - it is the barrels that are hard to move.) This part of the iron is rather rough with lots of machining marks so I guessed that was a good place to start since it looked like it needed some smoothing out. It opens a bit easier now but I think it could still be better. I actually took to much off and the forend began to wiggle easily on the barrels when the gun was in battery. I had to adjust the spring driven catch to get the forend tight again. I removed the extractor and stoned all the edges until that moved freely but I do not think that helped with the problem much. When opening it, it is the last few degrees that are the hardest. I also carefully stoned the leading edge of the receiver to be sure that there were no odd burrs or other defects there that might cause a problem like this.
