Who fired on the advancing rebels at the springfield armory and what happened to the rebel forces?

Massachusetts State militia.

Explanation:

Shay's rebellion was a rebellion that lasted from 1786 to 1787 in central and western Massachusetts. It got its name from Daniel Shays. He had participated in American revolution, his rebels were known as Shaysites.

Shaysites were farmers who were angry due to taxes and debt. As they couldn't pay their taxes due to debt crisis and the farmers were afraid that they would have to go to jails or their homes would be confiscated.

The shaysites tried close the courts forcefully to stop them from taking property of indebted farmers. The Shay's rebels marched on the Springfield Armoury in 1787 to seize arms and overthrow the government. The rebellion was put down by a privately funded local militia and Massachusetts State militia.