questions on my first mortar.

[machinehead]

hello,

I worked a bit on my first mortar last night.  I am going for a scaled down version of the 24pdr for golf balls.  Heres what i got so far,   a tube with a bore of 1.735-1.740, and a powder chamber 1" full radius 1.062 deep.  My bore diameter seems a little sloppy in the way of windage.  I had down to shoot for 1.730 but i gouged the bore with the radius tool and took out the gouge marks.  Is this bore going to be too loose, my bore length is 3.937.  The refrence section has down proper windage of 1.723.   I have seen people on here making them from 1.700-1.750.  I am planning on making a mold to shoot lead balls also.  

I have another tube that was bored out on the high side too im thinking of taking it out to fire 2" aluminum kinda pointed slugs with a radiused base.  Is a slug a waste of time on a coehorn.    Will it just tip end over end.  

The stock i have is 4"  i could do a straight walled confederate beer can with this and be safe.  The walls would be .667.  i have not seen any drawing of a confederate mortar to make it accurate.  The formula shows windage to be .066, are they really made with that loose of a fit?  How longe should the bore be.  The can measures in at 4.815.  cannon manias has about 3/4" sticking out of the barrel How big of a powder chamber are we talking about on here.  Once again cannon manias picture seems to be about half the size of the bore.  How does the half size coke cans (8oz i think) work.

Sorry to have all of the questions.  This is my first artillary piece and i want to do it safe, accurate, and have a good time.  My co worker just told me a story about a cannon that one of his co workers made out of brass for the 4th of July.  Everyone was standing around watching it as he lit the fuse, nothing happened.  so  he added more powder and relit it.  well a big bang happened.  The cannon blew up.  There was around 30 people there, and no one was touched.  They found 1" chunks of brass  100 ft past them.  So this is why i ask questions on all i do.

[Cat Whisperer]

Very good questions from a very safe perspective.

You're cool on the windage.  Less is ok, requires more cleaning between rounds, more is ok too, may use a little more powder (that's not going to break any of us with the MASSIVE amounts burned with a golf ball tosser). A little more windage just lowers the pressure a little - not a bad thing in our sport.

Whatever you shoot will tumble a bit.  I've seen it with 4.5" pvc pipe and 24oz soda pop bottles both filled with concrete and shot with close clearance tubes.

Golf ball morters do hook and slice a little.  Don't know why, just my observation.  Golf balls are very light compared to their cast iron counterparts.

Look at the safety rules for competition in the N-SSA and the American Artillary Association (should be links to them in our sticky's).  They keep people alive by observing them.

[Double D]

Very good questions from a very safe perspective.

A little more windage just lowers the pressure a little - not a bad thing in our sport.

Look at the safety rules for competition in the N-SSA and the American Artillary Association (should be links to them in our sticky's).  They keep people alive by observing them.

To ad emphasis to what CW said.   Windage isn't there just as a aid in loading a fouled bore.  It does that some what, but in a properly swabbed and wiped bore fouling should not be an issue.  Windage is also an aid in control of  pressure.  Less windage means higher pressure and a greater need for more precise control of the dimensions of our projectiles.

[guardsgunner]

In addition to the above. With the proper windage, if for some reason/ failure, the gun needs to be unloaded, it can be do so be tipping the mortar forward. projectile will roll or slide out.
   Originaly the windage allow the fuse in the top of the shell to be lit with the blow by of the charge.

[Cat Whisperer]

In addition to the above. With the proper windage, if for some reason/ failure, the gun needs to be unloaded, it can be do so be tipping the mortar forward. projectile will roll or slide out. ...

WORDS OF WISDOM.  It is WELL WORTH a little prevention to preclude situations that cause the 'pucker factor' to be elevated past the comfort level.

[CU_Cannon]

My first mortar had far too much windage.  It was drilled to 1.75 and then bored to smooth it out.  The result is a bore of around 1.8.  There is a lot of blow past with that much windage.  I've found that a wad or two of news paper behind the ball helps greatly.  You just have to make sure that there isn't dry grass where you are firing.  It isn't much for accuracy or distance but it is still a lot of fun.

[Powder keg]

Hi, when I need to clean up a drilled hole I've found that a bit of coarse emery cloth wrapped around a broom handle or dowle with a slitt in the end to hold it, works really good. I can post a picture if anyone needs 1000 words.