mortar wall thicknesses for brass

[mortarfied]

Hello All,

I recently found a chunk of 6" brass/bronze round about 12" long and have decided to build a mortar with it.  I am currently in the "getting ideas" phase, and have come up with a couple of questions that I hope you can help me with.

I have noted the "calibre-thick walls" rule of thumb for powder chambers but have also noticed that most of the designs were in steel.  Will brass walls have to be thicker?  Since I don't know the alloy of the material, I have to assume its soft.

How large a bore can I put in this piece? Or stated another way, what do you think a "natural" looking bore would be that would shoot something common like golf balls, tennis balls, croquet balls, etc.  I hadn't planned on shooting anything very heavy from it, but I saw someone mention designing for the accidental case that something heavy does get fired from it.

Thanks in advance.

[jeeper1]

A golf ball bore (1.70inches) is certainly doable. With a powder chamber the apparently popular 2.25 inch bore is probably safe but I wouldn't go over 2.625 inches (soda can). Be sure to save enough metal to make trunnions.

[Double D]

You have a piece of brass that would make an ideal scaled down 24 Pdr .  Scale it down to to 6 PDR.  Bore 3.67.

Order the plans from Antique Ordnance Publisher for the Federal Coehorn and scale the demensions down accordingly.  Look on the Cannon resource list at the top of the board for the link to AOP..

Forget shooting toys and sporting goods, get some solid zinc balls and go for it.  You can shoot them on the same range as golf balls and have a whole bunch more fun.

 

[GGaskill]

Since a mortar is chambered, you shouldn't have any problem.  Just don't let the back wall get too thin.  Beer can (for cheap and available projectiles) or 6 pounder bore are both reasonable.  Evaporated milk cans (about 3") would also be good.