Author Topic: Bowling Ball Mortar (Read 2756 times)

moose53 · « **on:** January 23, 2012, 10:08:54 AM »

I have wanted a Bowling Ball Mortar for a long time , Finally have the materials and pattern for a nice one .Should take most of 2012 to finish. I also plan to use the three segment interrupted threads,should be a interesting project.

GGaskill · « **Reply #1 on:** January 23, 2012, 11:05:13 AM »

Do you have plans for that 3.6" mortar or will you be estimating from photos?

moose53 · « **Reply #2 on:** January 23, 2012, 11:49:13 AM »

I don't have plans and will be estimating from the photos. Did the scans show up, had trouble loading them?

Cat Whisperer · « **Reply #3 on:** January 23, 2012, 11:52:54 AM »

Pictures and pdf's came through well.

GGaskill · « **Reply #4 on:** January 23, 2012, 12:13:29 PM »

Site with more pix

Previous thread with link to interesting old book with M1890 data

If you want to make a breechloading mortar for bowling balls, I think scaling down the M1890 12" mortar would work better than scaling up the 3.6" mortar.

seacoastartillery · « **Reply #5 on:** January 23, 2012, 12:56:07 PM »

Moose, have you calculated a weight on this rather large pup?

VERY cool project!! In-process pics would be real nice.

Tracy and Mike

moose53 · « **Reply #6 on:** January 23, 2012, 03:50:55 PM »

Thanks for the extra photos , they show the elevating system better . The material I have lends itself more to the 3.6 mortar,its just big enough . I plan on using a dedicated trailer for the mortar so it can be moved around and it needs to be heavy when shot more horizontal.

Frank46 · « **Reply #7 on:** January 23, 2012, 05:13:46 PM »

I sure hope that you will document your build like you did with the 37mm one. With your craftsmanship this one should be a stunner. Frank

smokemjoe · « **Reply #8 on:** January 24, 2012, 05:15:39 PM »

That will be a fine looking gun and the hours you spend on it be worth it when done, How much powder will the chamber hold. Thanks- for the pics. Joe

Frank46 · « **Reply #9 on:** January 24, 2012, 05:25:11 PM »

From looking at the pics, it looks like this could be broken down for ease of moving it around. Maybe you need to get one of those truck mounted lifting devices for lifting the pieces around. The ones I have seen were capable of
lifting a full 55 gallon drum. Maybe 450 pounds?. Frank

moose53 · « **Reply #10 on:** January 24, 2012, 06:33:34 PM »

Did a quick little figure and the barrel itself is going to weigh about 1500 lb, if I didn't mess up the figures. Sure adds up fast when it gets big.

Double D · « **Reply #11 on:** January 24, 2012, 06:38:42 PM »

You really should consider sending a letter to ATF and get approval for this project.

Enclose your plans, information on method of ignition and the type of projectile. I think they are going to say go ahead, and that's good. Hang onto the letter and use it should you decide to sell this gun in the future it will save you grief. They will respond in 6 to 8 weeks.

This is an ambitious and cool project, good luck with it.

ironball · « **Reply #12 on:** January 24, 2012, 07:39:40 PM »

Not capable of firing fixed amunition, pre 1898 design, yadda, yadda, yadda. Why would anyone need ATF permission to build something perfectly legal?

GGaskill · « **Reply #13 on:** January 24, 2012, 08:11:23 PM »

Why would anyone need ATF permission to build something perfectly legal?

Because you are dealing with a government agency that, like the IRS, likes to throw its weight around. And, also like the IRS, is a favorite of the sitting administration.

Cat Whisperer · « **Reply #14 on:** January 25, 2012, 12:37:39 AM »

Quote from: ironball on January 24, 2012, 07:39:40 PM

Not capable of firing fixed amunition, pre 1898 design, yadda, yadda, yadda. Why would anyone need ATF permission to build something perfectly legal?

Because of their past behavior.

jamesfrom180 · « **Reply #15 on:** January 25, 2012, 03:22:07 AM »

Really some people should be chastised for just plain hating. The ATF letter is just a good idea like having a owners manual for a car.

Does this design for the mortar follow exactly the original or will the breach vary? Very curious on what type of thread and how you will orientate the touch hole. Was looking over the long Cecile plans and though about this build.

little seacoast · « **Reply #16 on:** January 25, 2012, 04:22:56 AM »

It might just be easier to ignore them. Civility has long been the strength of this board, long may it continue.

Double D · « **Reply #17 on:** January 25, 2012, 04:39:24 AM »

Quote from: ironball on January 24, 2012, 07:39:40 PM

Not capable of firing fixed amunition, pre 1898 design, yadda, yadda, yadda. Why would anyone need ATF permission to build something perfectly legal?

How do you know it's legal? Are you a U.S. Attorney? What is your authority to give legal advice? Can your words be used as a positive defense in court of law? Are you going to go into court and straighten the Judge out?

moose53 · « **Reply #18 on:** January 25, 2012, 06:01:22 AM »

That might be a very good idea DD ,it could same me a lot of trouble explaining to a uninformed cop what I was doing with a cannon that big.

Double D · « **Reply #19 on:** January 25, 2012, 06:28:31 AM »

Quote from: moose53 on January 25, 2012, 06:01:22 AM

That might be a very good idea DD ,it could same me a lot of trouble explaining to a uninformed cop what I was doing with a cannon that big.

If you want some help crafting such a letter, drop me an email.

moose53 · « **Reply #20 on:** January 25, 2012, 09:09:12 AM »

DD enclosed is the letter to the ATF for your consideration . With your experience working with government types your comments are very welcome . Thank you . Moose53

seacoastartillery · « **Reply #21 on:** January 25, 2012, 09:13:08 AM »

Quote from: moose53 on January 24, 2012, 06:33:34 PM

Did a quick little figure and the barrel itself is going to weigh about 1,500 lb, if I didn't mess up the figures. Sure adds up fast when it gets big.

Yikes! I knew it was going to be over 600, but 1,500 LBS., WOW!! The thought of how much Mike's future bowling ball mortar will weigh is REALLY scary. He wants to build a bowling ball scaled, Mallet's Mortar!! Don't have time now for calcs, but I bet it goes north of 2,400 pounds for the tube and it's bed.

Almost forgot, will it be rifled as was the original? If you want it to be, you can talk to Mike. He has figured out a special Rifling Head for LARGE, but Short, tubes. According to Mike theory. all you have to do is find bowling ball ammo where all the balls are within .015" dia. of each other. He plans to use very thin lands which can cut plastic and broad grooves in his "Couture" style of rifling.
He has also figured out how to get the bowling ball behind the rifling in a muzzle loader too. Very neat trick.

Moose, Thank you for carrying the torch for creative project builds!!!

Tracy and Mike

moose53 · « **Reply #22 on:** January 25, 2012, 09:39:37 AM »

Sometimes heavy guns are actually easier to deal with because it forces you to find a better way of handling them. Mine may come close to 2500 lb with bed, the 3.6 inch mortar bed had 1 inch walls. I am planning on a smooth bore for simplicity and the fact it needs a sleeve to bring it from 9 inch bore to 8.625inch bore.

jamesfrom180 · « **Reply #23 on:** January 25, 2012, 10:02:23 AM »

Still curious moose about the obturator in the breach, are you going the the Bange or similar seal type or copper washers?

moose53 · « **Reply #24 on:** January 25, 2012, 10:19:28 AM »

The obtruation will be same as used in 40mm breach loader I just finished , copied after the DeBange system.

Double D · « **Reply #25 on:** January 25, 2012, 10:28:00 AM »

Quote from: moose53 on January 25, 2012, 09:09:12 AM

DD enclosed is the letter to the ATF for your consideration . With your experience working with government types your comments are very welcome . Thank you . Moose53

,

I worked your letter over a bit for you. You were writing in the past tense and is sounds like you already have the gun and you want to write in the future, if you let me here is what I will build...

The key to writing this type of letter is to provide them with the answers to their questions before they ask them. The issues will be:

Is the gun pre 1899
Does it use fixed ammunition
What is the bore size (remember we are dealing with two different laws here- NFA and GCA-NFA applies over .50 cal)
Type of ignition

I attached the clean-up pdf

moose53 · « **Reply #26 on:** January 25, 2012, 02:12:28 PM »

DD please look at this again, I changed loose powder bags to aluminum foil and bore to powder chamber. Thank you

Double D · « **Reply #27 on:** January 25, 2012, 03:07:27 PM »

Quote from: moose53 on January 25, 2012, 02:12:28 PM

DD please look at this again, I changed loose powder bags to aluminum foil and bore to powder chamber. Thank you

Great!

One thing I have thought about is the ignition.

Change it to this and send the letter, good luck;

Ignition will be via a striker and primer as was done on the original pre 1899 gun.

moose53 · « **Reply #28 on:** February 06, 2012, 02:48:07 PM »

I can work on a few parts before the ATF letter gets back because they will work on other guns also . Here is the breech screw , it is 5.375in OD by about 9in long . Thread is 2Tpi

Double D · « **Reply #29 on:** February 06, 2012, 03:29:12 PM »

Hey Blaster Bob, check out the powder can in that Picture!!