Loads for a 3/4" bore "Dictator" mortar?

[shred]

Hi all, I've been working on a 1/16th-scale M1861 (150th Anniversary?!) 13" Seacoast mortar-- mostly off William Green's plans for a 1/8th scale firing "Dictator" model with modifications for the size shrink and to get a some more bolts on there (cosmetic only, most of them).  If anybody's interested, I can probably put together some construction photos into a build log of sorts.  Here's the blurry 'artsy' photo to hide the rough edges

[Edit: Here's the build thread: http://www.gboreloaded.com/forums/index.php/topic,237417.msg1099345534.html ]





Anyway, it's done enough to fire so now I'm poking around for loads to try in this thing and not coming up with a lot specifically for mortars-- the FAQ thread chart suggest about 100 grains is reasonable for a 3/4" bore cannon.  The Green plans suggest 80 grains for the 2x larger version.  Neither suggest a powder size; I have a little 4F on hand and can find typical BP rifle supplies locally (though not likely cannon-grade).   The tube is probably only 1018 steel, but 2.8" dia with a 3/4" bore (slightly over for windage actually), so lots of steel all the way around.

I have some 3/4" ball bearings which might not be ideal shot, but are on-hand-- is 100 grains really ok for a steel ball?  About how far is it likely to fly? 20 yards? 200?  l'll likely mostly shoot blank loads, so suggestions for loads/wads/etc there would be appreciated as well.

Thanks

[Double D]

First for  mortar to determine loads use the Powder chamber diameter as bore for determining loads.

Look up loads for pistols in the caliber of of your chamber.  Then reduce that by at least half and start shooting.  Slowly increase the charge until you find a good load that will toss your ball at a reasonable enjoyable range.  If you load so heavy that you can not see the ball fly and land, not only is it not fun but it isn't safe either. 

Nice mortar by  the way and do post build pictures.

[Cannoneer]

shred
That's a fine looking model of the 13-inch seacoast mortar, and I'd like to see the build photos.

[RocklockI]

shred that is a very nice looking mortar ! If you ever put 100 grs of powder in it ...you will just think it a noise maker . Not unsafe if it built correctly but you will never know where that ball went !
 
Does it have a chamber ? If it does then that should be your guide . 25 grains of 2f will send a pool ball @ 75 yards in my 2.1/4" South Bend cohorn mortar . 
 
There is a pool ball down range where we shoot ...it is less than 100 yards away from where we shot the mortar . I can not find the darn thing !
 
I've been looking three times now when we go to the Pawnee National Grasslands .
 
You could proly get away with 4F in very small quantities ... maybe 5-10 grains to start ,but if you can get 2F OR 3F you are in bidness ! But still start with 15- to 20 grains . It is amazing how little powder it takes to send a mortar shot along way it is because of the chamber .
The fun of a mortar is watching the ball soar and then plunge to earth with a terrifying thump ,THEN you go pick up your balls and do it over agian    yea it's very cool .
 
Good Luck ...and Welcome ! shred / Nice looking piece 
 
Gary

[shred]

Thanks guys.  I ask a question at midnight and get several good answers by the time I wake up!   The bore is a straight drill, so no powder chamber as such, just the point from the end of the drill (I'm plotting to make a golf-ball tube with the same outer profile later on to swap in as needed... that will have a chamber).  I'll get some 2F and give it a try somewhere with lots of room.  Photos may be a bit, but I'll plan to post them.

[Cat Whisperer]

shred -

WELCOME to the board!

As DD (Double D) has said, we'd love to see the pictures from the process of making it.  (As well as pix of future smoke and flame!)

[keith44]

definately smoke and flame

[shred]

Finally got around to shooting some smoke-n-flame pics from this guy.  These are all one firing photographed at 60 frames per second.
One .45 LC case full of 4F loaded loose.  Unless they see the smoke cloud the neighbors don't even notice.

Ignition!













Just  bit of orange fire left

fire all gone

[little seacoast]

In a Dom Carpenter 3/4" Dictator, I find that 15 grains of 2F is a gracious plenty to send the ball 50 yds+. Nice build you have there sir.

[keith44]

In a Dom Carpenter 3/4" Dictator, I find that 15 grains of 2F is a gracious plenty to send the ball 50 yds+. Nice build you have there sir.

what kind of ball do you use at 3/4 inches?? Lead sphere muzzleloader type, or other??

[little seacoast]

I use a lead sphere @ .745 made from a mold that a board member was gracious enough to loan for that purpose. Also fits my Dom Dahlgren on a sliding barbette carriage which makes it especially convenient.