The gun is a wheellock which historically appropriate. I recently went to the Tower of London where there are some 16th century wheellock pistols on display.
Here's a little story concerning Elizabethan weaponry:
In 1579 a young man called Thomas Appletree was showing off to some friends in a boat on the Thames. He had a gun and was firing off shots for the fun of it. Nearby the Queen was entertaining the French ambassador on her royal barge, and one of the bullets managed to hit a crewman, injuring him. People were convinced the Queen had escaped an assassination attempt. Appletree was found and confessed to firing the gun, and was condemned to death. A gallows was erected near the scene of the 'crime'. At the execution, Appletree mounted the gallows and told the people watching that he was not a traitor, but admitted he had been careless and stupid, and believed he deserved to die for endangering the Queen. Essentially, he'd been a bit of a twit! The noose was put round his neck and at the moment of execution, a man stepped out of the crowd from the Queen with a written pardon. She had known he was just a silly young man, but he had to be taught a lesson.
What we learn from this, is Elizabeth the First had a twisted sense of humour!