Making A BB Mortar

[smokemjoe]

1. cutting end off
2. 6 in. flat
3.cutting to length
4. powder chamber, 6x6 in.
5.Boring chamber, 2x2 in.

[Double D]

Finished bore
Milling tunnion flat
 Fit to Chamber

[Double D]

 2in. ball Milling bottom, same used to mill tunnion.
ball fit to chamber
drilling vent
making skid, Hickory outside,pine inside, 30x12x12

[Double D]

drilling vent
making skid, Hickory and pine

[Double D]

drilling vent
making skid, Hickory and pine

Elv. screw, 1 in. x 18 thread with a die spring on end for recoil,

[Double D]

Joe,

I moved your pictures for you.  Post any more pictures to this thread an we will keep every thing in one spot.

Why did you put the powder chamber on the out side and not the inside?

entsminger-Scott the way he has made this tube is exactly how you should make the bore and chamber for your mortar.  Support the whole thing inside the propane tank.

[smokemjoe]

2in.radius ball mill, Milling bottom, same used to mill tunnion.
ball fit to chamber
drilling vent
making skid, Hickory outside,pine inside, 30x12x12

[Double D]

I would cut the chamber loose and fit it inside the tank.  Weld the trunnion bar and the bottom of the chamber to the tank.  Before you put the chamber in side drill and tap the vent for a tube that will go from the chamber to the out side of the tank.  

If the chamber was inside, you could then inlet the base to hold the barrel at 45 dgrees and have no need for an elevator.  I predict the elevator bracket you have is going to bend or break.

[smokemjoe]

Lining parts to wled and heat before welding

[smokemjoe]

Finish Welding And Shooting

[smokemjoe]

Ball in air, went 400 yds.

[smokemjoe]

Want to thank DD, Brad and others with the help getting me to post pic. I found this site in Jan. Never dreamed of making a Golf Ball mortar, then Doms soda can mortar and now the bowling ball mortar.
   When I go to a yard sale I hear people talk about some guy shooting BBs when there is a BB for sale.
   Also J- Mar Pattern Shop for all the help.  Joe- Dubuque Iowa
                   Hope youall enjoy the pics.

[Ex 49'er]

Thems are great pictures of your build. Congratulations on a great looking mortar. Thankyou for sharing your fire and smoke pics.
That is a good looking range where you shot yer mortar.
How much powder do you use per shot?

[smokemjoe]

The range is Aldeo Ill. Cast bullet Assc. club,The last target fram is 200 yds. 4 oz. powder and a 12 lb. ball landed in the second row of tree, 400 yds. The mortar made a loud ring when the ball left the barrel, it looks like it went up in the air 175 yds. to where it was looked like a marble, Then comes down and makes a whistle noise, Then sounded  like a screen door banging when it came down in the trees, What will the mushrooms think next spring when they find the balls?

[Cat Whisperer]

The range is Aldeo Ill. Cast bullet Assc. club,The last target fram is 200 yds. 4 oz. powder and a 12 lb. ball landed in the second row of tree, 400 yds. The mortar made a loud ring when the ball left the barrel, it looks like it went up in the air 175 yds. to where it was looked like a marble, Then comes down and makes a whistle noise, Then sounded  like a screen door banging when it came down in the trees, What will the mushrooms think next spring when they find the balls?

Ahhhhhhh YES!   The snap-thud of breaking limbs and hitting the ground!  There is NOTHING like it!

I REALLY LIKE the powder chamber back behind the tube.  It makes for clean lines.
How did you do the offset in the plate on the elevation adjuster?

[smokemjoe]

 The angle on the ends is 50 Deg.The steel plate is 2- 3/4 x4 in. angle iron I guess you call it.A  hole was drilled throught it for a 1 in.by 8 threaded rod. this didnt sit flush so we cut the plate and in a press formed it so the rod and spring was flush against the barrel. nut welded for the screw. Then the cuts was weld and with the heavy die spring we hope it dont bend, I had a 5/8 screw on it with a adjustment wheel, about 5 shots and it was bend and pushed the center out of the wheel. Recoil seems to push down and back. Barrel dosnt recoil backward. Hope this answers helpThanks for your you comments. Joe

[smokemjoe]

drilling vent
making skid, Hickory and pine

Elv. screw, 1 in. x 8 thread with a die spring on end for recoil,1 1/2x 3 1/2

[Double D]

I have some concerns about stability.  Right and left.  The base is narrower than tall.  Not some thing you need to fix, just something to watch.  Look for lateral spread down range from side to side wobble. First time it tips over fix it. If it never tips over keep shooting!

Are you bringing it to Montana next year.  We only have 200 yards.

[smokemjoe]

DD : So far I have sat it on a piece 1/2 in. plywood, 20 in.x 60 long. just slides back about a foot. Thanks for advise, I want to be save. , I sure glad I put  that heavy piece of steel on for a powder chamber, when it goes off its really something. The base must wt. about 80 lbs. and the barrel about the same. 2 pieces is all you want to lug around, 2 steps, Would one of those 8 in. chimmy brushs work for cleaning the barrel before swabbing the powder chamber out. Joe

[Double D]

My stability concerns are not front to back but tight to left.  I am concerned it will tip over on it side.   

Just stick a garden hose in it and rinse it out, then wipe it dry.  After its dry oil it good.   I use NAPA ATF 5 for oiling.

[js2346]

Awesome pictures! I like the way you beveled the outside edge of your powder chamber where it gets welded to the cylinder. What radius did you use? I've got a tank I'll be cutting open soon. Hope the ball fits inside. Did your tank have a DOT3AA2400 rating on the side?

[smokemjoe]

 Sir : Yes you got the right tank, Mine said the same, The angle is 30 deg. and 1/2 in. flat on it, That way you can get the more weld to flat on the tank and get the other 2 passes on top of that one, Make sure you heat both parts up  1st. and tack weld them so they dont move when welding, Joe

[Double D]

put the chamber on the inside.  It will look more like a Mortar that way.  The CG will be lower and you won't have a weld to get blasted by the black powder gases when fired. 

[entsminger]

  Most interesting! Looking at these will get me back to wanting a huge lathe and milling machine so I could bore out a huge hunk of steel for the barrel of my 13 inch mortar.  The tank I can easily find but where do you find such large hunks of steel to work with that makes the powder chamber like this fellow did?? I'm trying to equate this with my mortar so I'm guessing for mine it might be good to find around a 15 inch block of steel and somehow bore it out to 13 for the powder chamber and then attach it to a seamless pipe of about one inch diameter? Am I making sense here?

  Scott

[GGaskill]

Start by calling the companies on this page.  Another list is the Chesapeake Area Metalworking Society page.  This is another list of steel suppliers in the Baltimore area.

[js2346]

Double D - Thats an interesting thought you have with placing the powder chamber on the inside. Do you have plans or a link to help us envision how it would be built? Looks like Joe used a similar design to the Florida mortar. This is how I planned to build mine but I'm alway open to looking at other options. Thanks

[Double D]

Plans, no.  Not needed.

Yes that is the Florida mortar, Interesting thought, no.  It's what I have said each and every time some builds one of these things and puts the chamber on outside.

Instead of butting the front of the chamber to the hole in the bottom of the tank slide it all the way in and weld the bottom of the chamber to the tank.   Add trunnion and vent liner.

[GGaskill]

If you have the machinery and a few extra dollars for the greater amount of metal, make the breech plug fill the whole breech end of the cylinder.

[nematode]

When I saw the title to this thread I jumped in expecting to see a miniature cannon that shot actual bb's and now I realize the BB stood for bowling ball! Interesting. I had seen a really cool video in youtube where some guy was shooting a tiny cannon and knocking things down or breaking them with tiny bb's... very cool. I think it was someone in this forum that made the tiny cannon? Anyway bb or BB... both are cool!

[1Southpaw]

bb is for bb's and BB is Big Balls