I have finished the main storyline, I sided with the railroad and the minutemen. Before I finished the story artillery smoke grenades brought down a rain of explosions in the immediate area. After completing the story I cannot get a single artillery grenade to work. I am close enough to plenty of bases with attended artillery guns. The grenades go off and the smoke rises, but no shells are fired. Am I experiencing a bug or does artillery stop working after the story?

Hmm... only advice I can offer is to tune your radio to Radio Freedom and then toss the smoke. They should make a comment of some effect: "Sorry General, outside of our range" or "Commencing fire". IF you get an affirmative remark or no remark at all, then it may be a bug.

Thank you for the tip. I tuned in to freedom radio and found out the generators at castle were damaged in a attack so the transmitter was not working. After I got the radio station back up and waited for a day artillery started working again. So it seems like the Freedom radio station has to be online for artillery to work.