Author Topic: HELP...Need info for purchase of MORTAR!! (Read 1453 times)

Blaster · « **on:** February 14, 2005, 05:22:30 AM »

Help. I have checked into a web site listed in our Supplier Guide which lists here on the BP Cannon/Mortar board. It is the site listed as bigshotsofidaho.com. On that site there is a bowling ball MORTAR, and in the picture, it is on a pallet, suspended off the ground by a chain hoist. It is painted light blue/gray. I'll have to part with a lot of my stuff to possibly get this mortar but before I get too deep into this, I'd like to ask members of the board just what questions I should be asking of the fabricator.
I already have a list of items to ask him but anymore imput (even the very basic stuff) from my fellow board members will really be helpful. That mortar weighs 700 lbs and I believe the cost is in the neighborhood of 2K and I certainly don't want to rush into this buy without finding out a lot about the mortar.
Any help from you all will really be appreciated. Thanks! Blaster (Bob in CO)
Also, I have to let this fellow know if I do or do not want it within the next day or so.....Thanks

Double D · « **Reply #1 on:** February 14, 2005, 06:33:26 AM »

Bob,

Ask the usual questions. What's it made off. With a mortar and particularly of this size you can get away with the bore being seamless. You definitley want to know How the powder chamber is constructed and don't accept seamed tubing there. A fully machined powder chamber is preferred, but a properly construction breech plug is is okay. Check "The more Complete Cannoneer" for the proper method of constructing a breech plug

This is an impressive mortar.

Double D · « **Reply #2 on:** February 14, 2005, 06:45:58 AM »

Are you going to sell any of your Cannons to finance this deal? Which ones and how much?

OH, yes try this with your wife to make the deal go easier. Tell her you will let her shoot it. That has never worked with my wife, but who knows might with yours!

Blaster · « **Reply #3 on:** February 14, 2005, 07:03:13 AM »

DD... Thanks for the advice. I currently do not anticipate getting rid of any of my shooters. If I do, however, I'll sure let you know. Just got a message from the builder and he stated merely, "ok the tubes dom". I just responded telling him that I know nothing about metals and the fabrication process and don't know what "dom" is. Hey, I just enjoy shooting/collecting them, not building em.
Also, my wife would probably enjoy taking the first shot of a BB mortar providing she can use my cranium as the projectile. :cry:

John N · « **Reply #4 on:** February 14, 2005, 08:07:18 AM »

I did a quick internet search of DOM steel. Check out http://www.copperweld.com/pdfs/DOMBro.pdf It gives a good definition of "Drawn Over Mandrel" steel, including the benefits of DOM tubing and a description of the manufacturing process. They also have a specs sheet at http://www.copperweld.com/pdfs/DOMSpecs.pdf

Other links featuring DOM steel is: http://www.metalsdepot.com/products/hrsteel2.phtml?page=rndtube&LimAcc=$LimAcc and http://www.thomasregisterdirectory.com/tubing/drawn_over_mandrel_dom_tubing_0066927_1.html .There are lots of sites offering DOM tubing.

Double D · « **Reply #5 on:** February 14, 2005, 08:19:03 AM »

DOM would be fine for the bore of the tube in this gun, but the powder chamber should not be DOM.

Blaster · « **Reply #6 on:** February 14, 2005, 09:53:33 AM »

John N and DD, thanks for that info. Now I do know what DOM is. And, I'm still holding out for more information from other board members, for other information that I should be asking of this builder. The uncertainty of the integrity of the tube is what I am most cautious about. Of course, the cost of this mortar is also of great concern. Keep em coming folks.
:-)

John N · « **Reply #7 on:** February 14, 2005, 11:07:25 AM »

Blaster, are you sure the price is around $2K? I saw some of the other mortars on Big Shots of Idaho's listing in the Sticky: "Where to find Blackpowder Cannons and shooting supplies" post, and they are significantly more expensive (and don't look as impressive). Also is the barrel vented?

Blaster · « **Reply #8 on:** February 14, 2005, 12:42:22 PM »

Yeah John, the guy even sent an e-mail picture of the very same mortar. And he did tell me that it weighed 700 lbs, price of $2,200 but it'd be 2K if I pick it up to save shipping charges. It's definitely the same one in the picture and you are correct, it looks a lot more substantial and professional than others on his site. One of the questions I'll have to ask him is, if the powder chamber is also DOM or is it a separate piece welded on and how are the trunions attached (pressed in and welded or just welded on to the tube). If I bombard him with all the questions, he may tell me that he's not even interested in selling to ME. He has made some very impressive equipment and I hope to find out just how many of this particular model he has made and what, if any, problems people have encountered with them. I hope to hear more from you and other folks too and I'll keep everyone posted as to what if find out. Blaster (Bob in CO)

Cat Whisperer · « **Reply #9 on:** February 14, 2005, 03:20:32 PM »

Quote from: blaster

... the cost is in the neighborhood of 2K ....

Buy is a 4 letter word. Consider making one first.

Recognize that buying guns (and cannons/mortars) is an EMOTIONAL decision. It may well be a fullfillment of a dream.

There is nothing like big bore! One of my 2 favorite shootin' irons is the 155mm self-propelled howitzer - nothing quite like it. Pull the lanyard and ride it out like a roller coaster being inside it. The noxious smell of powder, the blast shaking everything all around you. And then the rush to get it loaded to fire another round inside of a minute.

Seeing the 155 round hit a car body (on the practice range) and the HUGE ball of flame as the steel burns - with the top doing lazy circles straight up and the hood and trunk lid doing tight circles in opposite directions along the ground. Then the sand and dirt and clouds of smoke clear and there's nothing left. (And there's no one shooting back at you in anger!)

That's one of the high points in life - if it takes getting an 8" spherical ball chucker - get it!

Blaster · « **Reply #10 on:** February 15, 2005, 05:14:28 AM »

Quote from: Cat Whisperer

Quote from: blaster
... the cost is in the neighborhood of 2K ....

Buy is a 4 letter word. Consider making one first.

Recognize that buying guns (and cannons/mortars) is an EMOTIONAL decision. It may well be a fullfillment of a dream.

CW -- consider making one first??? I don't think so. I am not mechanically inclined like almost EVERYONE on this board. I know the proper and safe use of common hand tools but beyond that, forget it. I know my limits quite well.
As addl. information, the maker has advised me that the DOM has and inch and an eighth wall, 22-inches from muzzle to powder chamber and the breech plug (w/chamber) is "sweated in". Isn't the process of sweating in going to be the same as welded in?? I have some pictures that he forwarded to me plainly showing the tube and the breech plug about to be applied, but am reluctant to forward them on to anyone else since they are pretty large. Blaster (Bob in CO)

Cat Whisperer · « **Reply #11 on:** February 15, 2005, 11:38:49 AM »

"Sweated in" could mean something like silver-soldered or brazed; or it could refer to the outside being expanded by heating and the inside being pressed in then cooled (shrinking around it). Not a very descriptive term.

Blaster · « **Reply #12 on:** February 15, 2005, 12:42:47 PM »

You are correct CW, in that the term "sweated in" really makes a person wonder just what method is actually used. Seems to me like there has to be some serious welding to accomodate the pressures generated in launching a bowling ball, which I believe weighs somewhere around 16 lbs., so I'd hate to see the breech and tube separate. If I can find a way to reduce the size of the pictures that he sent me, of the tube and breech prior to being assembled, I'll see if I can hopefully post them on the board, somehow or other. Posting a picture is still a super challenge for my very tired and worn-out old brain. Blaster (Bob in CO) :oops:

Cat Whisperer · « **Reply #13 on:** February 15, 2005, 12:59:51 PM »

The really high pressure peak, as I understand it, occurs early on in ignition - in the powder chamber, the pressure lessens as the gas expands into the tube. AND there's a bunch of square inches of area on which to push that large black globe. It may well be the design he has works and will work for some time (two different issues) - what is his track record?

Blaster · « **Reply #14 on:** February 15, 2005, 02:23:55 PM »

CW: I sent him an e-mail just last night, with a bunch of questons and one of them was asking, about how many of this particular model have been sold to the public and has he had any customer problems/complaints about them, if so what were the problems. Now just have to rely on his integrity to respond truthfully, which I have doubt that he will.

Cat Whisperer · « **Reply #15 on:** February 15, 2005, 02:52:17 PM »

References would be great.

I'd like to see a picture of the back side to check out the design of integration of tube and powder chamber.

What I see so far I like.

Double D · « **Reply #16 on:** February 15, 2005, 05:16:24 PM »

From what I see, my guess is that the breech plug was shrunk in place. The tube was heated and the plug frozen and put in place.

The first thing I would do if I got that mortar is pull the tube and have a welder weld the plug in place.

John N · « **Reply #17 on:** February 16, 2005, 01:54:35 AM »

Blaster,

Correct me if I'm wrong, but I get the impression that the owner of Big Shots of Idaho is not very forthcoming or particularly easy to deal with. If that's the case, too bad for him. After all, an important aspect of running a business is customer service.

I'd like to contrast this to the experience I've had with Canadian Cannon Company. Bill McGregor is one class act. Also, I noticed a new supplier on the cannon maker sticky, Loose Cannon Gun Works. I sent him an e-mail asking about the bore size of his tubes and got an immediate, detailed and very friendly response. (Bore size is 1.25"). The owner, David Steele, said he had "left out a rather important piece of information!!! We will correct that tomorrow on the website."

There are a lot of very fine, trustworthy cannon makers out there. I hate to see a seller make a potential buyer go through a lot of pain to get reliable information about their products.

Double D · « **Reply #18 on:** February 16, 2005, 02:40:17 AM »

John,

It would appear from the post that you are right. But I know from behind the scene helping Bob with the pictures and all that Big Shots has been forthcoming.

Bob has come to us here on the board to get the technical questions both formed and answered.

When we give the questions to Bob he has been asking them and getting answers. Some times Bob doesn't understand the answers and he has been asking us for help there.

About the only thing I see wrong with Big shot is that their Marketing skills are a little weak. Looks to me like the are builders and not computer programmers and salesman. There website is a good example.

It does sound like David Steele has his act together.

From what Bob has posted and the emails he has sent me he has been collecting a list of question to ask. He has been using us for a sounding board. Bob is calling Big Shots today with his list.

Here is the list he has prepared.
1. Actual bore diameter
2. How thick is barrel from the bore to outer surface of tube
3. Depth of bore down TO the powder chamber (sub chamber)
4. It does have a sub chamber doesn't it
5. Depth and width of the sub chamber
6. Trunnions size
7. Are the trunnions welded into pockets or merely welded to outside of tube
8. Is the sub chamber fully machined or is it a properly constructed breech plug
9. Is there a breech plug screwed in AND welded
10. Recommended powder charge of how many grains FG or Cannon Grade for bowling ball
11. Is powder poured in loose or wrapped in aluminum foil?
12. Elevation device - is that the wedge on a chain in the pictures
13. Is the tube vented and ready to fire?
14. Diameter of the vent/touch hole
15. Is the base and tube already painted or primed and with what kind of
paint
16. Is the one in the picture, the only one you have built and is it on hand right now
17. Have you sold very many of this particular model and has any of your customers had ANY problems with them
18. Can the entire gun (tube and base) be lifted using the one eye hook on top of the tube?

Can any one think of anythig else he needs to ask.

I would say Bob is a pretty astute shopper!

Double D · « **Reply #19 on:** February 16, 2005, 06:07:27 AM »

This picture kind of concerns Bob and I.

You need a bore of 8.815. A bowling ball is 8.595 diameter.

This picture is of the tube for the mortar Bob is looking at.

If those number mean anthything written on the tube the O.D. isn't big enough let alone the I.D.

Circumference of a bowling ball. Max 27.002 inches. 27.002 x .31831 = 8.595 maximum diameter of a bowling ball. Bore diameter (8.595/39)x40= 8.815 inches http://www.topendsports.com/sport/tenpin/dimensions.htm

Blaster · « **Reply #20 on:** February 16, 2005, 08:06:19 AM »

Quote from:

1. Actual bore diameter-- 8.625 + about 40 thousands
2. How thick is barrel from the bore to outer surface of tube--1 1/8" wall
3. Depth of bore down TO the powder chamber (sub chamber)-22"
4. It does have a sub chamber doesn't it--yes
5. Depth and width of the sub chamber--size of a shot glass
6. Trunnions size--3"
7. Are the trunnions welded into pockets or merely welded to outside of tube--welded to rear of breech.
8. Is the sub chamber fully machined or is it a properly constructed breech plug--machined and radius on mouth.
9. Is there a breech plug screwed in AND welded--sweated then welded.
10. Recommended powder charge of how many grains FG or Cannon Grade for bowling ball--3 oz FG
11. Is powder poured in loose or wrapped in aluminum foil?-in baggie
12. Elevation device - is that the wedge on a chain in the pictures-- yes
13. Is the tube vented and ready to fire? Yes and has been fired/tested
14. Diameter of the vent/touch hole--forgot to ask this...
15. Is the base and tube already painted or primed and with what kind of
paint--primed
16. Is the one in the picture, the only one you have built and is it on hand right now--have sold numerous other and this is only on on hand.
17. Have you sold very many of this particular model and has any of your customers had ANY problems with them--no problems so far
18. Can the entire gun (tube and base) be lifted using the one eye hook on top of the tube?--yes

These are the answers I received today in a phone conversation with Bill.

John N · « **Reply #21 on:** February 16, 2005, 09:48:41 AM »

Blaster,

Sounds like you have all the bases covered. I'm also glad to hear that Big Shots of Idaho is working with you and Double D on a major (and a HEAVY :grin: ) purchasing decision.

8.625 + 40 thousandth = 8.665" which is still a little tight for proper windage using the traditional formula which Double D calculated at 8.815" for a bowling ball. However I suspect standard bowling balls vary in size by several hundredth of an inch (the MAXIMUM allowed size being 8.595" per Double D's reference source). It might be that the bore size on that mortar won't present an issue. But I guess you'd want to check a bowling ball with a tape measure to make sure it's OK to shoot.

Double D · « **Reply #22 on:** February 16, 2005, 10:03:18 AM »

Oh, I can't resist...Blaster you are going to need a bowling ball ring guage!!!!

John N · « **Reply #23 on:** February 16, 2005, 10:21:25 AM »

Double D,

Good one!

Blaster,

Your GO-NO GO guage should be around 8.45" :lol: lol

Cat Whisperer · « **Reply #24 on:** February 16, 2005, 12:30:34 PM »

So if you shoot bowling balls - do league rules apply?

Is scoring the same? What does it take to break a 100?

Do you have to shoot EVERY Tuesday night?

What about those special shoes?

Cat Whisperer · « **Reply #25 on:** February 16, 2005, 12:41:26 PM »

Quote from: John N

.... 8.625 + 40 thousandth = 8.665" which is still a little tight for proper windage using the traditional formula which Double D calculated at 8.815" for a bowling ball. .... .

Bowling balls are very regular in dimension, that is very very round, though varying some between bowling balls. In contrast to casting iron, zinc or aluminum - where there is much more variation in diameter of a given sphere - unless it's turned on a lathe, but even then there will be irregularities.

The other function of clearance (other than to accomodate different diameters of spheres) is that it will assist in limiting pressure in the tube - more clearance = less pressure; therefore safer.

In any case the rule of thumb is good in that you KNOW it has been proven by experience.

Blaster · « **Reply #26 on:** February 16, 2005, 04:10:55 PM »

BAD NEWS.... After talking to Bill McKenna at Bigshotsofidaho, and telling him that I am very very interested in his bowling ball mortar, I called the fellow who WAS going to buy something from me that would provide the major portion of the cost for the mortar. The bad news was that he will not be able to make the purchase from me due to some unexpected large expenses coming up. So, I had to tell the BB mortar fabricator that the purchase is now off indefinetly. I did assure him that his web site got some extra coverage by other board members due to my sincere interest in his mortar. So, I guess I go home with my tail between my legs and just feel bad. Thanks for all who offered help and suggestions. They were appreciated. Finally, the fact that the mortar would cost me 2K plus about $360 shipping now makes the possibility of my purchase even further away. Blaster (Bob in CO) :cry:

Cat Whisperer · « **Reply #27 on:** February 16, 2005, 04:37:04 PM »

Indeed as setback - but hopefully only temporary!

We have all profited from this exercise and learned from it.