A Picture of I've Decided

[Smoothbore]

The middle of last month I posted a thread for input on whether to make a cannon or mortar out of a piece of 13" x 3" bronze stock.  As was said I had decided to make a mortar for reasons cited back then.  With the help of a friend with a "machine shop" drill press I was able to get it drilled for the trunnion rod (Is it called a trunnion on a mortar?).  Now on to making a base for it.

A question for you mortar experts here:  The "mortar" is pictured below, and some statistics are, the bore (golf ball) is 9 inches deep and the walls, of the more turned down portion, are 0.61 inch thick---the question is, what would be a recommended load of either cannon grade or 1F BP.  Also what do you think the max load should be limited to???

Also pictured is another object---it started out as a small cannon barrell, but do to operator error---I fed a cutter a bit too fast and it jammed and wrenched the stock in the chuck, causing a fair bit of damage.  After turning off the boo-boo areas, I wound up with---well as soon as I fine a suitable staff on which to mount it---a Hand Gonne!!

[Double D]

Mortar bores are usually about two calibers long.

[Rickk]

Is there a sub-chamber, or is it GB size all the way down?

[accuratemike]

Is your mortar/howitzer sub-chambered? The .61" thick walls of the tube would be fine (I think), but a caliber thick at the chamber is recommended. If it is sub-chambered, what are the dimensions of the chamber? If it were 3" dia around the chamber, the chamber should be 1" dia at the max. Mine has a 1" x 1" chamber, I think that is big for a golf ball mortar. My tube is steel and the bore is a tad less than 2 bores long. MIKE

Rikk beat me to it

[Smoothbore]

DD---I realize the general perspective of a mortar, but I had a nice piece of stock and really didn't want to cut off (waste) any of it, also it became somewhat of an experiment to see if my lathe could handle stock that big (definitely the upper limit!).  While it could have been fashioned into a cannon somewhat of a howitzer style---that would dictate the making of a carriage---something I do not, at present, have any appreciable amount of time to work on. 

It is GB bored all the 9 inches---no chamber.  While I would have loved to have a chamber drilled/bored, that was not an option at the time (a saga too long for here), so I had to settle for a simple bore.

The bottom line here is this is a tube (cannon/mortar--whatever) that has a 9 inch bore and .61" walls.  My question is still posed to those of you with the experience---what would be the recommended charge of cannon grade and/or 1F BP?

Smoothbore

[GGaskill]

As long as you stick to golf balls, you should be OK.  I would start with 100 grains of Fg and see if that shoots the golf ball out of sight.  Not much point in shooting farther than you can see.

[Double D]

13 x 3 inch would have made two mortars.  Or one mortar and a piece of trading stock to get a piece steel to make a cannon.  Still can do it  by makeing a screw in breech plug for the second mortar. 

[Smoothbore]

DD:

Though I could have made two mortars, I didn't really want two mortars that would have been essentially alike, and as I said in my previous reply, I wanted to see if my lathe (and me) could handle stock that big. 

As for still being able to make two mortars by making a screw in breech plug, well, that proposition has two big problems.  First, I do not have the equipment to do something like that.  Secondly, I, unfortunately, am far removed from the skill level required to make a screw in breech plug, or to thread the mortar for that plug. 

As for making a mortar and trading the left over piece---that thought never occurred to me.  I would have figured those of you on this forum with the equipment and skill to make cannons and mortars, like are so often the subject of a thread, would have, or have access to, just about whatever stock you might desire.  However, I will file this concept away in my memory banks for any future possibilities.

Smoothbore

[Tropico]

Have you decided on a carriage (Base) for this mortar ?  Myself I would probably use a custom sled base., High in the front but short in length forward of the trunnion.  Long and low in the back behind the trunnion to add weight behind the mortar., so that its not front heavy.  Actually the more I think about it., several base configs come to mind.
It looks pretty cool in its own right ., I would like to see finished pics and I bet it shoots a Golf Ball FAR., the length will add muzzle velocity !!!!

[Smoothbore]

Tropico:

I started on a base last night.  It is basically 6-18" lengths of 2x6 glued, and bolted together with 4- 7/16" threaded rods.  The dimensions thus are 5 1/2" high, 9" wide and 18" long. The inner two are cut out for the mortar, the next ones outward are drilled for the trunnions and the outer two just add size.  Tonight I will decide on how to do the elevation screw and if I have enough time will construct that. So far, without any finish work, it looks like it will turn out pretty good. 

I will not have it completed (sanded, painted, etc.) until this weekend.  I will reply to this thread with a picture of the finished product when I can---all things considered, that should be sometime next week.

Smoothbore