Hi, All. First post and my first attempt at mortar making.

[m223]

First of all I want to say what a great forum this is, God bless America. I wish I would of found this site before I machined my first mortar. Oh well whats done is done. I have some pictures of my project, but have no clue as how to post them, so I will attempt to describe what I did. Awhile back I was at the dreaded cannon mania site and I saw the neatest thing, a 1/2 scale Civil War Coehorn mortar that would supposedly shoot soda cans of concrete a 1/2 mile with approx. 335g of fffg b.p. Then I saw the price  $799.00 ouch! Well any way at work one day I noticed in the scrap box a piece of round C.R.S. 6 inches in diameter and a little over 8.5 inches long .....hmmm, looks like a mortar to me! I was so excited I stayed over on my own time to use works Clausing lathe. All I had to go on was mental picture in my head and a coke can. So I faced off both sides of my stock, center drilled the bore side, did a pilot hole till I ran out of drill, then used a 1.250 drill for the sub chamber, I drilled maybe a little to deep. From the very bottom of the powder chamber to the back of the stock I have about 1.125 thickness . The sides of the powder chamber are about 2.25 thick. Next I used a 2" drill bit and bored down to a depth of 4.5 inches , this gives the powder chamber about 1.5 inches of depth x 1.25 diameter. After much time using the boring bar I got a tight fit on the can. Next I used a powered cylinder hone to get the bore real smooth. With the soda can empty it will slide down the bore all by itself, if I put my finger over the .125 touch hole it stops, remove finger it continues down. Not knowing that the Coehorn has its trunnion at the rear I milled 2 holes 1.250 diameter and .500 deep about 2/3 the way up the tube and press fit 2 trunnions. the projectile chamber is 1.750 thick except were I press fit the trunnions it would be 1.250.                                                Whew, are ya still with me? O.K. now I have some Questions? 4th of July is coming up and I would like some loud but somewhat neighborhood safe loads. Is an empty soda can w/ 100 grains  fffg a. a bad idea? If so any other ideas. seems like most are using ffg. Any comments as to a safe load for a concrete can or blanks appreciated. Thanks All!! Tracy  P.S. I am not sure if I have enough windage on this thing how does one check this? Thanks again!

[lance]

hi and welcome. if you just want noise, try putting a small bag of saw dust on top of the powder charge.

[m223]

Thanks for welcome Lance, I had not thought of that, saw dust would would probably work well, I was also thinking of a patched tennis ball. Have a good one! Tracy

[radio2]

Hi m223 and welcome, Check out this thread as I asked the same, I used a cardboard disc and packed it with grass clippings and 350 GR of FFg for a nice report!
http://www.gboreloaded.com/forums/index.php/topic,119999.0.html

[Cannonmaker]

m223'

The windage should be 1/40 of projectial. The bore for  soda can should be 2.63'' I am thinking.  I may be off .010".  I would have to look at my plans.  The windage is important as not to get a projectial stuck in the bore.  Even the 4.5" depth could cause a problem.

Rick

[GGaskill]

With a chamber that large, I would use nothing smaller than Fg powder, especially for shots with a shot.  I would suggest starting with a load of 1/2 ounce (220 grains.)  Adjust upward until loud enough.  Mortars are not the greatest guns for blank shots but will work with a cardboard wad.

[Cat Whisperer]

M223 - Welcome to the board!

We agree, this is a great place (both USA and this board).

Love to see some pix of smoke and flame!

[Double D]

Becareful with sawdust on a hot dry day it can start fires.

[Will Bison]

Hey, welcome aboard.

[m223]

Thanks , for the welcomes, and advice guys. I have already started a golf ball mortar, and now my friend at work is itching to make one also. Thunderpaw posted a great drawing for a G.B. Coehorn, I am going to try to stay close to that, So Thank you thunderpaw. I have yet to fire off anything yet, waiting for the 4th. As I am pretty new here I have not figured out how to post pics yet. I thought I saw a post on this somewhere I will try to figure it out. Thanks again M223

[Rickk]

I soak my cardboard wads in baking soda solution and let it dry so it won't smolder as much. I guess you could do the same thing with sawdust.

[m223]

 Well I at least figured out  how to link my pics finally, It isn't the nicest looking piece but not bad for not having any idea what I was doing. I figured out what it is though. It's a little Dictator! Sorry no powder can yet. Ill try to get smoke & fire soon! I'm going to try to make a heavy metal Dictator base for it. Have a good one folks.

[GGaskill]

Interesting.  Kind of a Model of 1861 style mortar.  I would have made the trunnions half as long and twice the diameter, though.  Kind of like this one.

[m223]

hey that looks pretty heavy duty, I suppose I could make some changes. I'm working on my G.B. mortar now, It looks much more prettier and authentic compared to my first attempt above. M223

[GGaskill]

I wouldn't make any changes unless the trunnions prove to be inadequate in strength.  But the info is out there if you want/need it. 

That one is bored for 2 1/4" round shot to use the same shot as a 2/3 scale Napoleon.  It is based on the 8" siege mortar; the wall thickness is a little too much proportionately.  The overall diameter is 6" so the bore should be 3" instead of 2 1/4".  But it is an interesting alternative to the Coehorn and M1841 styles that are most often seen.

[m223]

I guess I'll find out soon enough if the trunnions will hold. I think the 4th of July will be fun again , I'm looking forward to it like an 8 year old. Thanks for your input and the link. M223

[Cat Whisperer]

I guess I'll find out soon enough if the trunnions will hold. I think the 4th of July will be fun again , I'm looking forward to it like an 8 year old. Thanks for your input and the link. M223

Keep the support for the trunnions close to the tube and you have much less potential for bending.

Post some pix when you get to the smoke and fire stage!

[m223]

Will do!