Length of Coehorns

[Michael Az]

Something I am curious about is the length of the Coehorns. I have noticed the soda can mortars have the end of the can protuding from the barrel. I am pretty sure this is just to maintain being scaled correctly. I was wondering, would it be a sin to lengthen the barrel a couple of inches or is it more important to maintain correct scale?
Michael

[Double D]

AAA right now has what we believe is a typo in their rules. 

Barrel length shall not exceed 2 times the projectile length, while
projectile length shall  not exceed 3 times the bore diameter[/qoute]

That probably should say bore length and is a good safety guideline to follow. 

Upscale if you must use cans.  Or stay small and cast some aluminum or zinc balls.

[Cat Whisperer]

It is important to maintain scale IF it's important to you esthetically or is a requirement for participation in a particular event.

It matters not to the projectile.  Longer barrel, longer range, cleaner burning, less noise, less powder needed.

[GGaskill]

It is better to use the short soda cans (or cut off the long ones) as when they tumble in flight due to no rotation, they do not present such a long cross section to the air.  And that would lessen the need for a longer barrel (although a longer barrel would probably give longer range.)

You have to decide whether accuracy of the model is important.  Usually it becomes moreso as you get deeper into the sport.

[Michael Az]

Good points, thanks for the replys
Michael

[quackgr]

  you can take this for what it's worth. I have a bowling ball mortar and it's barrel lenght is 20 in.  I shoot a 16lb. ball in it and it takes 3 oz of black to shoot 600 yds. I also have a 87% scale Coehorn that shoots 16lb. shot puts, it's barrel is 7.5 in. an it takes 2.5 to 3 oz. of black to shoot 600yds.  the chamber design is more important than barrel lenght.

 gerald