We have not heard of anyone in the U.S. who is in production of an aluminum canon with or without a liner. There may be a few, but from what we have learned over the years, most manufacturers will not entertain the idea of adding even a little liability to their operation.
While not engineers, Mike and I have been present at many actual stress tests of aluminum test pieces and steel ones in a large aircraft plant where they endured increasing amounts of tension, torsion and compression. To say that the aluminum failed far before the steel is the understatement of the new century.
Although there are other important factors, a graphic representation of the 'Modulus of Elasticity' is probably the easiest way to rate the amount of stretching different materials will go through before failure. We found a new site recently which is very good for this purpose. Click on this site to see for yourself:
http://www.engineeringtoolbox.com/young-modulus-d_773.html And for those who think aluminum is OK because you have a little help from a liner, well rethink that more than just once!! You might not blow yourself up, but just think how much your life would change if you put a splinter through your neighbor's kid 200 yards away. Use extreme caution and always build cannons with EXTRA redundancy, Not Less. That's our advice.
Tracy and Mike
