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I wish I would have surfed the net looking for plans/pictures to build a sled for my new mortar this morning before I bought a mortar on ebay......... If some of you old timers would review my mortar

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&rd=1&item=280162301136&ssPageName=STRK:MEWN:IT&ih=018

and tell me how bad or good I really did... I plan to use this as a signal cannon on my 60th birthday in a few months. I was told I could use up to 3 level TBLspoons black powder and it will be loud.. Now that I have read several threads on this forum the question is because the walls are not equal size with the bore, will it be safe? The good news is that I found several ideas on this forum for my sled and one "furniture" sled I really liked.
 

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# 1.695 BORE = PERFECT GOLF FIT
# 5" CLEAR BORE DEPTH
# 2" DEEP X 1.250 POWDER POCKET

That is much more like a howitzer than a mortar, at least in muzzle loading artillery terms. The chamber is a little oversize both in diameter and length for golf balls but if you don't get carried away with the powder, it will be OK. Start with one tablespoon of Fg or Cannon.
 

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Welcome to the forum Castnet, looks like you'll be having a blast on your birthday ;D...... i'm kinda wondering what kind of sled you'll end up building? post some pics for us............ i guess i'm dumb, how much powder is a tablespoon? if someone held a gun on me and said reach in the kitchen drawer and pull out a tablespoon, well, you'd just have to shoot me ;D
 

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Castnet -

Welcome to the board!

You did good!

4140 is great stuff.

I agree that the powder chamber is a bit large in diameter - should have that diameter equal to the thickness of the material around and behind it for heavy loads - but golf balls are OK as they're light weight.

I hit 60 in June. Still in denial. Fired my first one on July 4th 1975 - anniversary of the first shot heard 'round the world (and did it at Ft Devens just down the road 20 miles from the bridge between Lexington and Concord).

First firing of your first cannon/mortar are memorable events - record it on film for us!
 

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A tablespoon (the measuring kind not the one you eat with) is a half-ounce, or 1/16 cup.

Three teaspoons equal one tablespoon.
 

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Terry said:
A tablespoon (the measuring kind not the one you eat with) is a half-ounce, or 1/16 cup.

Three teaspoons equal one tablespoon.
now i'm really CORNFUSED....... ;D ;D ;D
 

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First you did good. You have a cannon. There is never anything bad about that.

On the negative side the guy that built that gun has little knowledge of cannon and motar design and construction. Bore is a bit tight and walls are to thin, trunnions to small and may be to far back.

On the Plus side and this is a very big plus, he built the tube from 4140. 4140 is also known as gun or ordnance steel. It is very strong steel and I doubt that you will have any problems with pressure when using blackpowder in that. No the plus far out weighs the negative. and you have a perfectly shootable noise maker to celebrate your coming Senior Citizenship.

The extra double big plus you found us. We can help get your gun setup and shooting. Once you do that you can start thinking about your next cannon project.

Unit's of measure. Get cooking measurements out of your mind. Your not making cookies and you shouldn't use cooking measurements. You will find your self getting into trouble real easy if you use cooking measurments. You will find no credible reloading information based on cooking measurments. It's to easy to get an overload using these unknown quantity measures.

Get yourself some way to measure powder. Traditionally black powder is measured by volume in grains. In cannons it is recommended to weigh the black powder on a scale. Smaller guns like this volume is just fine. You need to know how much powder you are using. Our safety chart is measured in Grains For now just find your self a black powder measure like this:



These these cost $10 to $15 and are cheap if you don't have a scale. This type of volume measure will work just fine for your little gun. You can use it to determine the volume of other recomended items used for loading powder such as cartridge cases and film cannisters.

Based on postion of your trunnions, this is as George says more a howitzer than a mortar. Mortars generally have a bore that is about two calibers long with trunnions at the rear. There are exceptions such as the Dictator. Your bore is 2.9 calibers and has a great long extension to the rear of the trunnions You want to look to garrison, naval and field carriages not mortar bases. Let us know what you decide and we will help where we can.

Loading and firing. Check for the maximum load on the chart stuck to the top of this board in safe loads and cannon plans. The bore size to use is 1.25 and according to the chart your maximum load is 280 grains. Use only Fg or Cannon Grade black powder. For blank charge with no ball FFg would be fine.

You are going to need to make youself some cleaning tools. You will need 2 swabs, one to clean the powder chamber and one to clean the ball bore. You are going to have to clean that ball bore meticulously between shots. It won't won't take much to jam a ball in that tight bore. Onthe other hand I'll bet you get a good crack when it fires.

Well that should get you started. Tell us when you are going to fire your celebratory shot and we will all go out and fire an answering volley...any excuse to shoot you know!
 

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Discussion Starter #8
Thanks everybody, I feel much better. I will heed all the good advice and look forward to posting on this site for awhile. By the way, cannons to fire on New Years eve, Jan 1st, what a day for a birthday......Thanks again....
 

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Welcome you to the board, castnet, and congrats on your new playpurty (one of my Grandma's words)! You don't give your location, but I'm guessing by your handle that it's on or near the coast.


lance, you must not cook much!

It goes like this:

3 teaspoons = tablespooon
2 tablespoons = ounce (by volume, not the same as an ounce by weight)
8 ounces = cup
2 cups = quart
4 quarts = gallon


As Double D said, forget cooking measurements and stick with the more appropriate (and accurate) measurements of grains and ounces. There are 7000 grains in a pound, 437.5 grains in an ounce.

Kitchen measuring spoons by their very design are poor powder measures. They are usually shallow with a wide mouth, the opposite of an accurate powder scoop. And they come in a limited number of sizes, making fine measurements impossible. Measuring powder requires more accuracy than the average set of measuring spoons will allow.


But for the sake of reference, I got out a 1 tablespoon measure, a can of GOEX Fg, and my electronic scale.

Pouring the spoon full, and leveling with a card, I got an average of 224.3 grains. This was the average of 10 throws. Low was 221.3 grains, high was 227.9 grains.

Three tablespoons? That would give you a charge of about 673 grains! That's a LOT of powder!
 

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Terry, you are right! but i was doing what i was doing, to get folks to address the issue. Which Double D and you did. I knew 3 spoons full was 654g, by my old books. i just always think about maybe some kids getting on this site to gain some knowledge............ " little kid with a soup ladle" are you sure those cannon experts on the computer said 3 spoons full is o.k.? oh yeah, start with one and work up.......wait a minute! are you sure thats a tablespoon? why look at it! it's so big you'd need a table to set it on, so it has to be a table spoon............... I know i'm being silly, but little ones do watch. and if there is any little ones reading this!!! i know you're going to skip school and steal grandpa's cannon and shoot it. so please don't use spoons, use a powder measure, and powder chart.
 

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Just out of curiosity, did the maker tell you how he put the trunnions in? Often they machine them smooth to provide an interference fit into a hole they drill in the cannon, then press them in. That method isn't a problem if the maker leaves enough metal between the trunnions and the chamber or bore.
 

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Hello all
I have just purchased the same cannon . A golf ball mortar . I am also trying to figure out a carrage of sort to use to fire it . With the cannon I also received instructions . Use ffg black powder . Use 300 grains with golf balls. For blank loads use anyware from 600 to 1000 grains of ffg black powder . The instructions said to start with 600 grains and work your way up . I to am a beginner and learning a lot from all the input .
 

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mcneshp said:
Hello all
I have just purchased the same cannon . A golf ball mortar . I am also trying to figure out a carrage of sort to use to fire it . With the cannon I also received instructions . Use ffg black powder . Use 300 grains with golf balls. For blank loads use anyware from 600 to 1000 grains of ffg black powder . The instructions said to start with 600 grains and work your way up . I to am a beginner and learning a lot from all the input .
600? I think I'd start with about 10% of that and ram a wad of aluminum foil on top big enough to fill the rest of the chamber. Foil is a lot cheaper than powder...
 

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Double said:
Becareful using a wad of tinfoil. When fired the tinfoil will become a projectile so treat the cannon accordingly.
Oops.... I was thinking of when using golf balls. A wad of metal doesn't exactly make for a 'blank'.

Pay attention, folks (Me especially).
 
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