Cannon Ball Mould

[blue7.62]

What size ball mould would I need for a 1.6875 diameter bore shooting lead balls with a patch?
Thanks, Russ

[Terry C.]

You should NOT be using patched balls in a bore this large.

According to the commonly accepted formula for windage with unpatched balls, ball diameter should be 39/40 bore diameter.

(1.6875/40)39 = 0.0421875 x 39 = 1.6453125

At this scale I would call it 1.645" ± .002".

[Cat Whisperer]

What size ball mould would I need for a 1.6875 diameter bore shooting lead balls with a patch?
Thanks, Russ

blue7.62 -  WELCOME to the board!

What type of cannon/mortar?

WITH A PATCH?  NOT typically done.  When you get up past an inch or so the dynamics are different.

Note well that the common rule of thumb uses the term WINDAGE or clearance.

You are in a different league by using a patch - which is ok if  you are a mechanical engineer with EXPERIENCE in interior ballistics.

Our recommendations on this board are strictly in tune with the time-honored (read: successfully safe for a bunch of folks - not just one) practices that are recommended by the two large cannon/mortar firing organizations - the N-SSA and AAA (And Switlicks time honored book: The more complete cannoneer.)

I have seen a cannon explode from 15' away.  Commercially made.  Reasonable load, perhaps too much packing for the blank.

Cannons work well if KEPT within certain ranges.  The only way of knowing that you've exceeded the limits is when they come unglued.  SO, if you're using a patch at golf-ball caliber, don't. 

Don't take my message as too harsh - it's meant to keep you and our readers safe.

[Rickk]

golf balls are about 10 cents each plus shipping on ebay

[Terry C.]

Isn't 1.6875" too small for golfballs?

[GGaskill]

Isn't 1.6875" too small for golfballs?

Golf balls are nominally 1.68" so the barrel would have to be scrupulously clean for a GB to go in.  I do my GB bores at 1.700", or 1.719 (1 23/32) if I want to be able to shoot 1 lb spherical lead sinkers.

[blue7.62]

Thanks guys...
Awesome advice and info!

[Double D]

Got to our  References: Books, the web, and "How to build ..."  stuck to the top of the and you will find a link to bowling ball mortars.   Also further down inthe post under the subject" Bore Size of commonly used items for cannon projectiles:" you will find this:


A golf ball gun with proper windage would need a minimum bore of 1.723 inch.
The diameter of a golf ball is 1.68 inch. .  (1.68/39)x40=1.723
http://www.learnaboutgolf.com/beginner/balltypes.html


As to patching larger projectiles.  Properly seating a larger diameter patched projectile is difficult due to its greater surface area and the resulting increase in friction.  When fired due to this increase in friction and the greater mass of the larger projectile pressures will increase at a greater rate than in a smaller caliber. 

Matt Switlik has some good information in his book "The More complete Cannooner."  His tests from changing just from Cannon  grade to  FG  are eye opening. Here is a copy of the info on Switlik's book from our Resource list.

Warning
Shooting cannons is not like shooting a big over sized muzzleloader.  There  is a completely different set of internal ballistics  involved.   Read up on cannon shooting before you acquire a cannon. Suggested reading is THE MORE COMPLETE CANNONEER  By M.C. Switlik with selected excerpts from other artillery manuals
The book can be ordered from these two suppliers by clicking on these hotlinks:

• The Complete Cannoneer from Matt Switlik
• South Bend Replica

[GAWI]

About using a patch, I have a do-it mold for a 2 1/4 bore. Its so loose i was putting a towel as patch. Bad? The is 2".

[Cat Whisperer]

About using a patch, I have a do-it mold for a 2 1/4 bore. Its so loose i was putting a towel as patch. Bad? The is 2".

A much smaller ball in a large bore is a dilemma. 

A SMOOTH bore is much less of an issue than one that is in any way rough or varying.

I have built up cylindrical projos with tape to ride the bore - much as the artillary shell bourlet's.

Patching tightly is not cool, to understate it.  A loose patch? Maybe a gamble - I couldn't say without seeing it.

[CrufflerSteve]

How about using a wooden sabot? That way a slightly undersize ball could achieve reasonable accuracy. Something like http://www.cwartillery.org/sshot.jpg would work. Either making the sabots or having them done should be somewhat affordable since woodworking is cheaper than metal working. It also addresses one problem I've seen in some cast balls - roundish as opposed to round. I had a sinker mold for my 2" bore and those balls were not at all round. Combining that with a patch pushes a cannon more towards a pipe bomb. I solved that by having Wes make a proper mold.
Steve

[GAWI]

With it wraped its not really tight, but its a 2" mould. After hollidays i will be checking with local machine shops about inlarging to the correct size. Every one i checked on about building one on these sights are not able to.