Our teacher Ms. Paladino told us we would be doing an activity flinging marshmallows next week.  My dad and I had already made a super-powerful nerf gun that would explode the darts, so we made a bigger one to try shooting marshmallows.  It looks like this:

We found some steel pipe that was the right size for a large marshmallow, and I welded it to a smaller pipe that fit the QEV.  Welding is awesome!  We tested it out this morning, and we shot marshmallows all the way across our yard - over 150 feet.

We did some math using the length of the barrel as a scale.  The marshmallow is going 134 MPH!

Here is a test fire: