Thats not a bad idea. Better than what I had before. I'm going to try and see if I can get a hold of one of the fuel cans, but if not that would probably be the best way to go. Thanks for all of you help guys!!!

Wow, thanks for the response Jimmy! You've got some good points in there. I think you're right, proper fueling is going to be a problem. The trouble is I don't know what to design around. The fuel cans are given to use on the day of the competition (maybe sooner for testing), so its tough to know ho...

Jack: Good point on the potato spinning itself apart, I will take that into account. I have reconsidered the barrel diameter, and I think I am going to go back to the 1.5" barrel. Its easier to rifle, the slugs will have more mass so they won't be as affected by cross winds, and getting a decent C:B...

Couple things I should have added in the beginning: 1. The target is lying flat on the ground 150 feet away from the launch point. These are more potato "morters" than they are "launchers". As I said, points are awarded for accuracy and consistency. The target has a 1' diameter, landing on the targe...

Actually, the barrel is going to be rifled. I came up with a way to get a surprisingly nice spiral bore along the barrel. I won't reveal details yet, until the cannons have been built and submitted, but it seems like it will work well. So, I see the thinking behind the 3/4" barrel, makes sense. I wi...

This cannon is for a competition that I have entered in, so the budget is fixed and the so are the supplies. I don't think I was clear enough, but all of the supplies listed are provided in the kit I have to use, and I have $20 extra to spend on additional supplies. It has to be potatoes.

Ok, so I have been assigned the task of building a potato launcher with the specific task of being able to a target 150 feet from the launch point, with a big emphasis on accuracy and repeatability. The launcher must be combustion and use the supplies provided, along with a $20 budget. Here are the ...