Author Topic: Bowling Ball Mortar Fan Club (Read 2141 times)

irontamer · « **on:** July 27, 2007, 04:41:43 PM »

Hi all, I've read every single thread about BB mortars in anticipation of building my own. I've never actually seen one, but a video on youtube got me all fired up, and y'all seem to have the best info on the web. I have a couple O2 tanks in my shop, but they're both too small OD according to the posts. Probably for the best, as I use them as they are. My welding supply guy is looking for me, but no joy so far. Argh!

Just asking for anyone with experience, advice and technical knowledge to explain the differences between the various powder chamber/ignition setups so when I get the right tank, I'll know what to do with it. I'm a custom welder/fabricator, but not a machinist. The references to trailer hitches bored out were a bit vague, so some clarification would be appreciated. Thanks!

John

GGaskill · « **Reply #1 on:** July 27, 2007, 07:01:58 PM »

The trailer hitch ball was being used as a ball-and-socket joint for training the mortar tube.

Cat Whisperer · « **Reply #2 on:** July 28, 2007, 12:41:42 AM »

Irontamer -

WELCOME to the board! There are a few tanks out there that will work. Haven't found the one with my name on it yet though.

As you know from reading, the critical thing is the powder chamber (to contain the high pressure spike) then the rest of the tube guides the ball under lower pressure. Marvelous idea from Coehorn.

m223 · « **Reply #3 on:** July 28, 2007, 06:06:27 AM »

Monkey see monkey do, I want one too! I'll keep my eyes peeled. If any one finds a bunch of these I would like to place an order. Tracy

Cat Whisperer · « **Reply #4 on:** July 28, 2007, 08:09:18 AM »

Next thing ya know we're going to have LEAGUE bowling - POSTAL match at that!!

lance · « **Reply #5 on:** July 28, 2007, 08:55:27 AM »

Quote from: Cat Whisperer on July 28, 2007, 08:09:18 AM

Next thing ya know we're going to have LEAGUE bowling - POSTAL match at that!!

not me Tim, i like golf balls just fine.........but i will be glad to help you man your bowling ball mortar.

GGaskill · « **Reply #6 on:** July 28, 2007, 01:27:50 PM »

Nothing beats bowling balls flying through the air, well maybe exploding shells flying through the air (see the Paulson bro's videos.) They're slow and easy to see (although some people claim they can't see them) and they whistle as they fly. Golf balls are barely the same game.

lance · « **Reply #7 on:** July 28, 2007, 04:12:09 PM »

Quote from: GGaskill on July 28, 2007, 01:27:50 PM

Nothing beats bowling balls flying through the air, well maybe exploding shells flying through the air (see the Paulson bro's videos.) They're slow and easy to see (although some people claim they can't see them) and they whistle as they fly. Golf balls are barely the same game.

i'm sorry,i think you misunderstood me.plus i'm the second person to post on Dom's Paulson bro's videos. see i live way out in the sticks, nearest bowling alley maybe 50 miles. never see a bowling ball at yard sales or fleamarkets, they are rare in these parts......golfballs are plentiful. Tim[cat whisperer] lives only a few miles from me. so if he wants to build a bowling ball mortar and find ammo for it, like i said i would be glad to help man the gun

Cat Whisperer · « **Reply #8 on:** July 29, 2007, 12:39:36 AM »

Lock and load one 16 lb Brunswick!

Someday.

m223 · « **Reply #9 on:** July 29, 2007, 07:06:44 AM »

Humm... that's true it's not every day you can find 4700 bowling balls on the ground. Golf balls are so much easier to come by. Ah what the heck I'm still in. Tracy

Fluxion · « **Reply #10 on:** July 29, 2007, 09:47:10 AM »

M223, if you find a local source for some tanks I just might be interested.

radio2 · « **Reply #11 on:** July 29, 2007, 12:45:08 PM »

Quote from: Fluxion on July 29, 2007, 09:47:10 AM

M223, if you find a local source for some tanks I just might be interested.

Count me in too!

m223 · « **Reply #12 on:** July 30, 2007, 12:47:22 PM »

Well guys I will keep a look out. Awhile back there was a gal at work whose husband dealt with oxygen and acetylene tanks. I will see if I can find their number. I haven't even measured the one in my garage yet. I wonder if the military gets rid of o2 tanks at the D.R.M.O.? Just a thought. Tracy

m223 · « **Reply #13 on:** August 01, 2007, 11:52:41 AM »

Well so far I have measured 4 O2 tanks and the circumference of all 4 is about 24 inches. It might be a real hat trick finding one of those fat 29 inchers , Then whose to say it will be the right inside diameter ; nonetheless I'll keep searching. Tracy

Fluxion · « **Reply #14 on:** August 01, 2007, 01:45:52 PM »

Well, got a hold of a few bowling balls for free and had a visit with the guys over at Kirk welding today. They can get me some old tanks but I couldn't find any over 29" I found a few H size argon tanks but they were right at 28.875 in circumference. I'll keep looking. In the meantime does anybody have a link to the construction of these things? I have used the search but it doesn't work so well for me. Oh, and my googlefu must be weak, I couldn't find much on the web either. I am hoping I can gather some materials and start construction sometime in me Sept. when I get back from the honeymoon.

lance · « **Reply #15 on:** August 01, 2007, 04:59:53 PM »

o.k. guys. you are winning me over. but,i'll probably take a different route........i have often thought about Hern Iron Works 1861 8" siege mortar, they also make one a little bigger for bowling balls. i guess bowling balls would be cheaper than iron or zinc.

m223 · « **Reply #16 on:** August 02, 2007, 12:21:42 PM »

Oh Lance, I see where Intodeep got his name. Would the bank consider that a home improvement loan? If I wasn't loosing my job I would buy one of those too. I think I might have to settle for a full scale mountain howitzer. I guess I'll keep looking for cylinders.

Tropico · « **Reply #17 on:** August 02, 2007, 12:26:54 PM »

That HERN Bowling Ball Machine looks awesome.

intoodeep · « **Reply #18 on:** August 02, 2007, 03:19:11 PM »

Quote from: m223 on August 02, 2007, 12:21:42 PM

Oh Lance, I see where Intodeep got his name.

Hey be nice....

The truth hurts you know....

Rickk · « **Reply #19 on:** August 02, 2007, 03:29:27 PM »

I doubt that cylinders have ever really standardized.... particularly the old one that have failed test and are more likely mortar candidates. I was chattin with the guy at the welding supply shop about old cylinders and he showed me some that are still in use. Some of them had Nazi markings on them... made over 60 years ago in Germany. If they pass test, they keep using them. So, who knows what you will find inside ?

irontamer · « **Reply #20 on:** August 03, 2007, 12:17:39 PM »

Well, one of the posts I read mentioned seamless oil well casing with an ID of 8.75". Sounds like that'll be easier to get, but I am a bit leery of so much welding on such a critical piece.

GGaskill · « **Reply #21 on:** August 03, 2007, 02:25:26 PM »

If you use something like well casing, you will have to make a breech plug from solid material to fill the closed end. It will contain the chamber so you won't have to worry about that. If you look at the plans associated with the golf ball mortar contest, you will see that the breech plugs are shouldered to stop against a corresponding shoulder in the tube. So the welding isn't in a highly stressed state.

lance · « **Reply #22 on:** August 03, 2007, 05:27:59 PM »

Quote from: m223 on August 02, 2007, 12:21:42 PM

Oh Lance, I see where Intodeep got his name. Would the bank consider that a home improvement loan? If I wasn't loosing my job I would buy one of those too. I think I might have to settle for a full scale mountain howitzer. I guess I'll keep looking for cylinders.

praying on your job situation....... i keep tossing the Hern " bowling ball machine" around in my head. can't decide to get just the main ingredient or the whole thing.i wouldn't have this problem if they didn't offer it that way. plus i would need to figure on some kind of trailer to carry and unload it for shooting. can't help it, mortars are my favorite.........

Double D · « **Reply #23 on:** August 03, 2007, 07:12:41 PM »

I am reluctant to use this drawing becasue it has a couple of errors, but I will anyway. This is for well casing.

Start with the "powder cup". The wall thickness is wrong, it needs to be one caliber. I would make this from a piece of solid round stock. 3 inch OD diameter by 4 inches long. Bore the interior cup 1 inch diameter by 3 inch deep. That is a lot of powder. This is really a small cannon with a bowling ball sitting on the muzzle. Every thing else is just decoration.

The main tube is an expansion chamber. The tube needs to be heavy to dampen recoil. The inner length of the tube needs to be 2 calibers from the face of the powder cup to the muzzle to fit the rule of thumb for CW era mortars. Might add some tubing bands for exterior visual effect.

I would build a removeable threaded vent liner.

Trunnions and round end? Ideas?

m223 · « **Reply #24 on:** August 04, 2007, 05:48:15 AM »

Irontamer, I must of missed your previous post, but I was thinking there has to be a easier way to do this, and I think you hit the nail on the head. I have to many irons in the fire at the moment, But when the time comes I think I will revisit the plans kindly posted by D.D. One of the machinists I worked with purchased a lathe and mill. If need be he will let me do some work out there, a round trip out to see him will cost over $35.00 in gas so I will need to get my ducks in a row before starting this project. Lance thanks for your prayers, I know I will be alright. It is just frustrating having to start all over again. Who Knows maybe its the best thing that could happen. I almost forgot about the g.b. contest thanks for reminding me Ggaskill. Tracy

dominick · « **Reply #25 on:** August 04, 2007, 01:20:02 PM »

I am working on designing a bowling ball mortar. Personally, I'm not too excited about using O2 cylinders. I am leaning towards 10 1/2" O.D. x 1.000" wall, cold drawn seamless tubing. Bore the I.D. to 8.750" and inserting the plug from the muzzle. I can see where the plug will be about 6" deep. The outside wall can be stepped to look like the Federal Coehorns. Dom

dominick · « **Reply #26 on:** August 04, 2007, 01:30:43 PM »

Here's a website that has what I have in mind. If you scroll down you will find a bowling ball mortar barrel for sale. I would machine The steps into the barrel instead of adding the bands. Not that there's anything wrong with the band method.

http://www.aaamunitions.com/items_for_sale.htm Dom

lance · « **Reply #27 on:** August 04, 2007, 02:39:03 PM »

Quote from: dominick on August 04, 2007, 01:20:02 PM

I am working on designing a bowling ball mortar. Personally, I'm not too excited about using O2 cylinders. I am leaning towards 10 1/2" O.D. x 1.000" wall, cold drawn seamless tubing. Bore the I.D. to 8.750" and inserting the plug from the muzzle. I can see where the plug will be about 6" deep. The outside wall can be stepped to look like the Federal Coehorns. Dom

now we're talking Dom, kinda throws a monkey wrench into the Hern plans though..... but with the money i'd be saving, well Gosh, i could get some more of your great creations.........

GGaskill · « **Reply #28 on:** August 04, 2007, 09:07:12 PM »

The outside wall can be stepped to look like the Federal Coehorns.

As I am sure you know, the Federal Coehorns were 5.82" bores while a bowling ball is 8.59". The 8" mortars of the 1840 patterns sort of resembled Coehorns with the trunnion at the rear and a narrow muzzle ring and slight tapering behind the muzzle, but they were not really very close copies. The 1861 8" mortars resembled Coehorns only in the sense they both had bores and vents.

I suppose if your customers want their BB mortars to look like Coehorns, that is their choice.

dominick · « **Reply #29 on:** August 06, 2007, 05:48:34 AM »

Quote

As I am sure you know, the Federal Coehorns were 5.82" bores while a bowling ball is 8.59". The 8" mortars of the 1840 patterns sort of resembled Coehorns with the trunnion at the rear and a narrow muzzle ring and slight tapering behind the muzzle, but they were not really very close copies. The 1861 8" mortars resembled Coehorns only in the sense they both had bores and vents.

Your right, The 1840 8" or 10" Siege Mortars and the 1840 Seacoast Mortar would be a closer replication for a bowling ball size mortar. Dom