Trumpeter's Soviet 2A3 Kondensator 2P 406 mm Self-propelled Howitzer

I am here just fiddling with the parts, doing some clean up and looking for ways to proceed later. Might as well take the time now and change the barrel shape, so that I am done with that. 

It isn't a big deal, but I wanted to reshape the barrel, it seems Trumpeter just shaped the whole thing as a tapered shape. Not easy to be sure, but I suspect the photos showing the inner part being silvery, means the inner part slides back in when the gun is fired. 

Re. the cannon barrel, I airbrushed on black matte primer and sanded it off again to get an idea if there were areas with unevenness. The excess black residue is just paint I never bothered to clean off completely.