Author Topic: Improving Accuracy of "Tin Can" Mortar Projectiles  (Read 6782 times)

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Offline seacoastartillery

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Re: Improving Accuracy of "Tin Can" Mortar Projectiles
« Reply #90 on: April 05, 2010, 10:02:21 AM »
Tracy,

So you mean I shouldn't have copied them to my funny photo file for future use........  ::)


You Colorado guys worry me, you really do!

It's that mountain spring water........ Coors always brags about.......

Allen <>< 



     Allen,   I guess it's OK for you and the other 3 people who check this thread every day to copy them, but for goodness sake, don't tell anyone else about those photos!   At least we never drive with our tin hats on, if you know what I mean.  Talk about hats, here's a true, short story about two of the Military Judges I met while stationed at Fort Polk, Louisiana during my Army career.  One wore a helmet to work every day; so did I, but I rode a motorcycle, the judge drove his car.  The other Courts Martial Judge showed me his final defensive fire weapons he had stashed behind the bench in his courtroom.  He had a big Colt .357 wheelgun and a a 3" Magnum 12 Gauge Shotgun with some of those long range Goose Loads!!  That pump shotgun must have had a barrel at least 32" long maybe a bit more.  I think that it WAS his Goosegun!

     Yes, they sure do brag about that springwater, but, having been brought up on Budweiser, the Colorado brand always tasted like what I imagine the flavor of horse piss to be.  When I say "brought up on", I don't mean after High School, I mean brought up on  .  When I was 7 or 8, I remember my Ma saying,  "Paw, this kid ain't too smart.  We are going to have to make him tough!"  That's when she started putting Bud on my breakfast cereal instead of milk.  It worked too.  I had one serious fight in High School; after that, Nobody messed with me.  ;)

Tracy

     
Smokin' my pipe on the mountings, sniffin' the mornin'-cool,
I walks in my old brown gaiters along o' my old brown mule,
With seventy gunners be'ind me, an' never a beggar forgets
It's only the pick of the Army that handles the dear little pets - 'Tss! 'Tss!

From the poem  Screw-Guns  by Rudyard Kipling

Offline Cat Whisperer

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Re: Improving Accuracy of "Tin Can" Mortar Projectiles
« Reply #91 on: April 05, 2010, 10:18:13 AM »
We could photo-shop them - adding the little black rectangles over the eyes.   ;D
Tim K                 www.GBOCANNONS.COM
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Offline Cat Whisperer

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Re: Improving Accuracy of "Tin Can" Mortar Projectiles
« Reply #92 on: April 05, 2010, 10:19:18 AM »
Douglas -  Do you give the Kewpies for photo excellence?   :D ;D :o
Tim K                 www.GBOCANNONS.COM
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Offline RocklockI

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Re: Improving Accuracy of "Tin Can" Mortar Projectiles
« Reply #93 on: April 05, 2010, 11:58:38 AM »
This is a close representation of an incident that that took place in my backyard . once .
      
  

may have to cut and paste to the address window  ;D

http://sz0013.ev.mail.comcast.net/service/home/~/jihadist_trainees.wmv?auth=co&loc=en_US&id=60560&part=2
 
  I dont know how to get it to work but if somebody knows they can tell me how to do it .

Gary
no cannons but you must be carefull with things that go boom . AC130 footage . dont tamp it too much !

maybe this time .

http://sz0013.ev.mail.comcast.net/service/home/~/jihadist_trainees.wmv?auth=co&loc=en_US&id=60560&part=2

 

 
 
 





"I've seen too much not to stay in touch , With a world full of love and luck, I got a big suspicion 'bout ammunition I never forget to duck" J.B.

Offline Double D

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Re: Improving Accuracy of "Tin Can" Mortar Projectiles
« Reply #94 on: April 05, 2010, 12:45:27 PM »
Douglas -  Do you give the Kewpies for photo excellence?   :D ;D :o

Basically that is what a kewpie is, but the phot has to be of a cannon .  I see a photo of a cannon and put the kewpie under the photo.  That's why I don't normally put kewpie on direct upload, I can't put the kewpie by the pictures.


As to photo excellence, the pictures up thread do have an element for prize winning, that is for sure!!

Offline Victor3

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Re: Improving Accuracy of "Tin Can" Mortar Projectiles
« Reply #95 on: April 06, 2010, 03:44:12 AM »
    Victor3,   Just remember what happened to your Sgt. York, AA system.  That was the end for V2 Technologies, wasn't it?  Chapter 11 reorg followed, right?  Well, my tin foil hat may look silly, but there is no silliness implied when I tell you that your vaunted S.M.A.C.K. projectile is in for a SMACK-DOWN from the Broomfield Cannon Manufactory's S.P.L.A.T. an Advanced, Multi-Vane, Guidance Assured, Projectile.  Remember our motto, 'Ours cost A LOT more, but you need only ONE'.

Tracy

 Ouch. Had to dredge that ancient history up, eh bud?

 Lookie here Mr. T, who was it who gave you - dare I say delivered to you on a silver platter - the RTV breech seal technology required for your see-ment water jug tosser to not blast your launch trailer to splinters?

 Who was that generous soul, eh Fairweather? ;)
"It is a capital mistake to theorize before one has data. Insensibly, one begins to twist facts to suit theories, instead of theories to suit facts."

Sherlock Holmes

Offline seacoastartillery

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Re: Improving Accuracy of "Tin Can" Mortar Projectiles
« Reply #96 on: April 06, 2010, 05:58:40 AM »
    Victor3,   Just remember what happened to your Sgt. York, AA system.  That was the end for V2 Technologies, wasn't it?  Chapter 11 reorg followed, right?  Well, my tin foil hat may look silly, but there is no silliness implied when I tell you that your vaunted S.M.A.C.K. projectile is in for a SMACK-DOWN from the Broomfield Cannon Manufactory's S.P.L.A.T. an Advanced, Multi-Vane, Guidance Assured, Projectile.  Remember our motto, 'Ours cost A LOT more, but you need only ONE'.

Tracy

 Ouch. Had to dredge that ancient history up, eh bud?

 Lookie here Mr. T, who was it who gave you - dare I say delivered to you on a silver platter - the RTV breech seal technology required for your see-ment water jug tosser to not blast your launch trailer to splinters?

 Who was that generous soul, eh Fairweather? ;)


     Thanks for getting this discussion back to cannons, Victor.  You know it's interesting you mentioned your genuine generosity regarding the RTV seal we used just prior to the Montana Model Cannon Shoot.  Mike and I really appreciated that suggestion!  My grandson was climbing all over the trailer and Paixhans Monster Mortar just last week and I decided to show him what an 11" bore and the 4" dia. X 8" chamber looked like.  Despite the wintertime freeze and thaw schedule and condensation moisture, that seal is still in really good condition and should serve us well at an early summer shoot.  We used a pound and a half of Fg Goex to boost a 137 lb. concrete slug out to a little over 400 yards during our high plains tests in Colorado prior to putting Southpaw's bowling ball into orbit with the same weight charge. The high-temp RTV held just fine.  Thanks again, Victor!  It's snowing today and tomorrow.  Looks like the good weather has shifted to Friday or Saturday, so you get to be KING for 4 or 5 more days, then your reign comes to an end.

Tracy

First testing of the Monster Mortar.  Timber cribbing under the trailer flys outward, as approx. 121,400 ft. lbs of energy is directed downward upon the trailer springs and shocks.  Log cabin style cribs worked much better on subsequent shots.  Projectile, Water Jug filled with Concrete weighing 137 Lbs.; 1.5 Lbs, Fg powder; range, 400+ yards.



Smokin' my pipe on the mountings, sniffin' the mornin'-cool,
I walks in my old brown gaiters along o' my old brown mule,
With seventy gunners be'ind me, an' never a beggar forgets
It's only the pick of the Army that handles the dear little pets - 'Tss! 'Tss!

From the poem  Screw-Guns  by Rudyard Kipling

Offline Div Arty

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Re: Improving Accuracy of "Tin Can" Mortar Projectiles
« Reply #97 on: April 06, 2010, 06:50:01 PM »

  Tracy,  is that 137 lb. projectile an approximate scaled down weight of the original?  Or was the original a shell and maybe lighter?

                     Thanks   Ron

Offline Victor3

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Re: Improving Accuracy of "Tin Can" Mortar Projectiles
« Reply #98 on: April 07, 2010, 02:03:25 AM »
 Love that picture. If you guys ever get a chance to fire the monster at night, be sure to have cameras ready.  ;D
"It is a capital mistake to theorize before one has data. Insensibly, one begins to twist facts to suit theories, instead of theories to suit facts."

Sherlock Holmes

Offline seacoastartillery

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Re: Improving Accuracy of "Tin Can" Mortar Projectiles
« Reply #99 on: April 07, 2010, 06:47:33 AM »

  Tracy,  is that 137 lb. projectile an approximate scaled down weight of the original?  Or was the original a shell and maybe lighter?

                     Thanks   Ron

     Thanks again, Ron for those nice photos of the cannon on the Naval Base at Norfolk, Virginia.  We really liked the Brooke, but I guess that would be expected.  There is a very interesting story behind the use of Le Mortier Monstre at the battle of Antwerp in 1832.  It's all on-line and pretty easy to find, but to answer your question, we have excerpted a bit from our history section of that Jan. 2009 thread:
                                                   http://www.gboreloaded.com/forums/index.php/topic,162341.0.html   


     "The experiment having succeeded, it was resolved to bring the mortar into Antwerp, and preparations were made to place it in battery on the covered way of the bastion of the city, between the re-entering place of arms of Montebello and the Malines gate. Eight horses were required to draw the carriage on which it was placed, and eight others to draw the carriage containing the bed. The weight of the empty shells being nearly 1,000 lbs. it is easy to calculate the number of these projectiles that could be moved in any ordinary ammunition wagon. The weight of the bed, which is of timber, is not given in the scale, but it may be taken as at somewhat more than the mortar itself, making altogether about 30,000lbs.; add to this 110 shells for 100 rounds at 1,000 lbs. each, and 110 barrels of 90 lbs. each, and it gives the enormous dead weight of 70 tons, exclusive of gins, triangle, chevalet, carriage, and sundries. The name of Monster-mortar seems to have been well selected, for it is scarcely possible to conceive a more ugly or unwieldy implement. With the exception of the mortar at Moscow, which has thirty-six inches in diameter at the mouth of the cylinder, and was, if ever used, employed for projecting masses of granite, the monster- mortar exceeds any other weapon of the kind hitherto known. The original conception is due to Colonel Paixhans ; it was executed under the direction of Baron Evain, and cast at the Belgian royal foundery at Liege.

     Firing.—At midnight, the twenty-four-inch mortar was loaded with twelve and a half pounds of powder, and the first discharge took place. The huge projectile, of which the internal charge was fifty-four pounds of powder and combustibles, was watched with anxiety as it made its parabola, and a look-out person stationed on the tower of St. Andre reported that it had fallen and exploded near the great powder magazine at the gorge of bastion Fernando. The success of the experiment was thus demonstrated. At the second shot, which took place nearly an hour later, the shell burst on issuing from the mouth of the mortar, not by explosion from the fuze, hut from the weakness of the projectile itself. Great care was therefore ordered to be taken in selecting others, of which the culots were thicker.

The dimensions are as follows:

Calibre massive, 23.62 in.
Thickness, exclusive of culot .. 2 in ,,
Weight of empty shell 9l6 lbs. ,,
Powder contained in shell .... 99 lbs. „
Weight of Shell, full charge ..1015 lbs. „
Weight of mortar (metal) 14,700 lbs. „
Weight of bed (wood) 16,000 lbs. „
Powder in Chamber (full) 30 lbs. ..

     The French weight has been preserved purposely for the sake of greater accuracy."

    So, you can see that while we built the mortar very close to 2/5 Scale, with an 11-Inch bore that was actually almost 46% of the original's 24", we looked around for a projectile that would fit without making complicated Monster Zinc Casting Molds or even Monster Concrete Molds.  The Water-Cooler Jug was the right size and available without a lot of hassle.  The chamber is exactly at 2/5 scale, and, when full, holds 2 lbs of powder VS 30 lbs of the full size gun.

     Victor, we have always wondered what it would be like to fire the Monster at night.  Maybe we will have to plan a campout on the prairie this summer to find out.  One thing we know for sure, we won't need the camera's flash to get the photo!

We got this pic off of one of the Montana Model Cannon Shoot movies we took of the monster firing under that big bright blue Montana Sky.  This was the fireball that resulted from a pound and a half of 1Fg Goex behind southpaw's bowling ball.  We never did see that particular ball again!  No pieces rained down either; it was just GONE!




Regards,

Mike and Tracy
Smokin' my pipe on the mountings, sniffin' the mornin'-cool,
I walks in my old brown gaiters along o' my old brown mule,
With seventy gunners be'ind me, an' never a beggar forgets
It's only the pick of the Army that handles the dear little pets - 'Tss! 'Tss!

From the poem  Screw-Guns  by Rudyard Kipling

Offline seacoastartillery

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Re: Improving Accuracy of "Tin Can" Mortar Projectiles
« Reply #100 on: April 10, 2010, 11:12:32 PM »
     Sunday is Test Day for the S.P.L.A.T. advanced Coehorn Mortar projectile.  Listen up competitors, mainly Victor3's, V3 Technology Corp. and their SMACK projectile with low cost, off the shelf technology and reasonable accuracy according to the maker, our primary concern is that the nose might be scratched upon impact.  We want to save the first test round for the Broomfield Cannon Manufactory's Museum and for this purpose we are concerned about appearances.  We have settled on 200 grains of FFg Goex to propel this experimental round.  Fine weather is forecast and all preparations have been made for an early departure for this initial test at our high plains range 100 miles NNE of Denver, Colorado.

Tracy


The entire core of the Deployed Vane Guidance System equipped, S.P.L.A.T. projectile showing the 1.5 Lb. steel nose weight, tape covered wood spacer, hollow aluminum vane deployment module(yellow), springs, hooks and vanes (black) and the Steel, Hook-Releasing Collar (red).




Close-up of Vane releasing Module showing vanes, hooks and only two guidance vanes for clarity and the graphite-lubed, red, Hook-Releasing Collar.  On firing, the collar stays where it is for 1/200th second due to it's 'Ineria-at-rest', releasing all vane hooks and the vanes deploy conically due to their attached coil springs which bring all the vanes to a tensioned, stationary position against the top edge of the round's outer casing.




The test projectile in it's "Range Colors", two 200 gr. powder charges and some Really Hot 1/16" fuse.


Smokin' my pipe on the mountings, sniffin' the mornin'-cool,
I walks in my old brown gaiters along o' my old brown mule,
With seventy gunners be'ind me, an' never a beggar forgets
It's only the pick of the Army that handles the dear little pets - 'Tss! 'Tss!

From the poem  Screw-Guns  by Rudyard Kipling

Offline Victor3

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Re: Improving Accuracy of "Tin Can" Mortar Projectiles
« Reply #101 on: April 11, 2010, 02:31:51 AM »
"...our primary concern is that the nose might be scratched..."

 And a valid concern it is. Happened to me as I thumbed mine at you (gotta get me a manicure).  ;D

 BTW, why did you prepare two charges? Seems a waste considering the inevitable outcome of the first firing.
"It is a capital mistake to theorize before one has data. Insensibly, one begins to twist facts to suit theories, instead of theories to suit facts."

Sherlock Holmes

Offline KABAR2

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Re: Improving Accuracy of "Tin Can" Mortar Projectiles
« Reply #102 on: April 11, 2010, 04:47:50 AM »
I love the black and white checker board paint job on the projo can......

Retro late 1950's -60's space program........
Mr president I do not cling to either my gun or my Bible.... my gun is holstered on my side so I may carry my Bible and quote from it!

Sed tamen sal petrae LURO VOPO CAN UTRIET sulphuris; et sic facies tonituum et coruscationem si scias artficium

Offline dan610324

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Re: Improving Accuracy of "Tin Can" Mortar Projectiles
« Reply #103 on: April 11, 2010, 04:58:23 AM »
or german V2 style
but it was the same man behind both of them  ;D
Dan Pettersson
a swedish cannon maniac
interested in early bronze guns

better safe than sorry

Offline RocklockI

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Re: Improving Accuracy of "Tin Can" Mortar Projectiles
« Reply #104 on: April 11, 2010, 05:42:44 AM »
with all this lead time ... I have been able to create a Anti Projectile Intercept Thinnage . Or APIT  .

This has been developed in great secerecy . The APIT is under the 'hush hush notell program' . Or HHNTP
'
Basicly small intercept payloads lauched in pulses , They are a monochromaticy identical , unidirectional , and Inphase . It's similar to an Iodine chemical laser utilzing borron doping with with silica waffer or solid state laser . But louder .

gaining and sheding electrons untill a charge is built up , abit like Photovoltaic cells .

When the resulting projos are at the size of ...say 00 buckshot they will be released in 12 greyballs to the pulse charges with up to 8 plulses per to the refill .

"I've seen too much not to stay in touch , With a world full of love and luck, I got a big suspicion 'bout ammunition I never forget to duck" J.B.

Offline Double D

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Re: Improving Accuracy of "Tin Can" Mortar Projectiles
« Reply #105 on: April 11, 2010, 07:40:19 AM »
SYBMIB+40OS theorem at its finest!

Offline seacoastartillery

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Re: Improving Accuracy of "Tin Can" Mortar Projectiles
« Reply #106 on: April 11, 2010, 05:53:56 PM »
    Victor,   Why prepare two powder chgs?  Because I needed two to have two completely successful tests, without any parts missing, even after the second test!  The vanes worked spectacularly, but you really don't have to take my word for it, even the slightly, out-of- focus movie, shows complete vane deployment and the start of a rapid end-swap maneuver.  Both shots landed nose first.  I will admit to being a bit shocked at the predictability of the trajectory after vane deployment and stabilization!  I will post stills now and my son will followup with two movies in about 2 or 3 hours from the time of posting.  What a great day!  Things hardly ever go this well.  :) :)

     Allen,   Glad you like the Retro look; I do too and it reminds me of the 'Old Days' of Rocket Inspection and watching as a 4,000 Lb. billet of aluminum got whittled down to a little over 500 Lbs. by the "Skin-Mill", a giant Gantry Milling machine that could mill a 1/4th section of rocket 'skin' in less than one 8 hr. shift.  These "Range Colors" should be clearly visible against the blue Colorado sky or brown prairie grass.  

     Dan,   Von Braun?  Never met the man; I started working on Titan III and Titan IV rockets about 10 years after he retired.

     Rocklock,   If you go out with us, don't bring one of those along, please.  How sophisticated is your targeting computer?

     Double D,   Huh?

    

Tracy


First shot went 75 yards with 200gr. FFg.





Almost hit a cow-pie at 75 yards.  Body of projectile was approx. 75 deg. off hoizontal when nose hit prairie at 10" out at 10 O'clock.





Dirt on nose and right side indicates a shallower impact angle.





All 12 vanes are there; we lost the red, steel, vane-releasing, collar, but that part takes only 10 minutes to turn.





This is where the Super Slo-Mo Movie will go in approx 2 hrs.

                      [quick=475,325] http://img44.imageshack.us/img44/3294/newshortslomo.mp4[/quick]

The Second shot series started with all vanes deployed as there is no way to hold them closed without that sliding collar.


Second series Starts here:  Second Test Shot landed with all vanes intact and deployed.  The nose impacted with the body almost erect at about 85 degs. off the horizontal.  See the cookie-cutter hole in that hard prairie sod.




This round rebounded just about straight up and landed as you see it here about 1 foot away.




Still has all 12 vanes and all were deployed evenly when this test shot #2 struck almost vertically.




2nd shot, real-time movie will go here in about 2 hrs.

                             [quick=475,325]http://img202.imageshack.us/img202/1263/standardspeedicm24.mp4[/quick]





Smokin' my pipe on the mountings, sniffin' the mornin'-cool,
I walks in my old brown gaiters along o' my old brown mule,
With seventy gunners be'ind me, an' never a beggar forgets
It's only the pick of the Army that handles the dear little pets - 'Tss! 'Tss!

From the poem  Screw-Guns  by Rudyard Kipling

Offline dan610324

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Re: Improving Accuracy of "Tin Can" Mortar Projectiles
« Reply #107 on: April 11, 2010, 07:15:04 PM »
wouldnt it had been easier to study this if the projectile had been scaled to fit the monster mortar instead ??   ;D
Dan Pettersson
a swedish cannon maniac
interested in early bronze guns

better safe than sorry

Offline Victor3

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Re: Improving Accuracy of "Tin Can" Mortar Projectiles
« Reply #108 on: April 11, 2010, 08:38:41 PM »
 Tracy, I am most humbled. I hereby publicly apologize for my scepticism of your S.P.L.A.T system.

 Your successfull launch may result in V3 Tech going into bankruptcy once again. Do you need a partner? Even Clinton and Obama seem to be working well together after all that mud-slinging during the campaign.

 What do you say, pal?  ;D
"It is a capital mistake to theorize before one has data. Insensibly, one begins to twist facts to suit theories, instead of theories to suit facts."

Sherlock Holmes

Offline seacoastartillery

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Re: Improving Accuracy of "Tin Can" Mortar Projectiles
« Reply #109 on: April 11, 2010, 10:33:02 PM »
     Dan,   You are absolutely correct, a larger missile is easier to study, especially one which goes as slow as a black powder projectile.  Maybe someday I will experiment with a guided Monster shell, but you have so much weight to overcome, I don't think it would be easy to do.

     Victor,   How can I refuse an offer like that?  I lost a lot of sleep over this contest, and spent lots of time away from my official duties as chief wood butcher at Seacoast, but it was worth it to bask in the warm sunshine of sweet success.  Partners?  Maybe after I am finished basking, not before.  ;) ;)  It was fun and I really can't remember when reality beat expectations, I really can't.  I posted the movies really late, so I have included links here and also a still from the real time movie just to show the flame from the 300 grain charge and the projectile 'streaking'. 


               Super Slo-Mo:        http://img44.imageshack.us/img44/3294/newshortslomo.mp4


                Real Time speed:    http://img202.imageshack.us/img202/1263/standardspeedicm24.mp4


                Still showing smoke and flames:     
Smokin' my pipe on the mountings, sniffin' the mornin'-cool,
I walks in my old brown gaiters along o' my old brown mule,
With seventy gunners be'ind me, an' never a beggar forgets
It's only the pick of the Army that handles the dear little pets - 'Tss! 'Tss!

From the poem  Screw-Guns  by Rudyard Kipling

Offline Cat Whisperer

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Re: Improving Accuracy of "Tin Can" Mortar Projectiles
« Reply #110 on: April 12, 2010, 02:12:37 AM »
SO,  was it more or less accurate than ( ... ) and by how much at what range?

Was not that the question?
Tim K                 www.GBOCANNONS.COM
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Offline Double D

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Re: Improving Accuracy of "Tin Can" Mortar Projectiles
« Reply #111 on: April 12, 2010, 03:32:18 AM »
SYBMIB+40OS theorem at its finest!


School yard boys, mine is bigger plus 40 years or so.... :)

Offline seacoastartillery

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Re: Improving Accuracy of "Tin Can" Mortar Projectiles
« Reply #112 on: April 12, 2010, 05:38:29 AM »
     Thanks Double D, I never would guessed that one in a month of Sundays!  With wild theorems like that one, I bet you could dodge thrown pies with the best of them.  Ann Coulter IS the best of them, of course!

     Cat Whisperer,  I will attempt to answer your question the way you answer so many, in such good humor, each and every week.
Ans:  A traveler, visiting Boston, Mass for the first time, and hearing of the excellent preparation of a certain kind of fish in culinary establishments in that town, asked the Cabby who came to his hotel to pick him up:  "Could you tell me where I can get Scrod?"  The Cabby thought for a moment and then said, "Sir, I have been asked that question thousands of times, but Never in the past, plu-perfect, tense."   ;) ;)

Tracy
Smokin' my pipe on the mountings, sniffin' the mornin'-cool,
I walks in my old brown gaiters along o' my old brown mule,
With seventy gunners be'ind me, an' never a beggar forgets
It's only the pick of the Army that handles the dear little pets - 'Tss! 'Tss!

From the poem  Screw-Guns  by Rudyard Kipling

Offline Cat Whisperer

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Re: Improving Accuracy of "Tin Can" Mortar Projectiles
« Reply #113 on: April 12, 2010, 01:18:00 PM »
Tracy -  I've enjoyed many fine meals in the fair city of Boston.  None in the plural past perfect tense, though.  And it was a few miles down the road, a bit past the bridge between Lexington and Concord, past Waldon Pond over in the township of Harvard (not the University) on the South ranges of Fort Devens where I fired my first mortar for the first time.  It was using a water-filled Coke can and was on the 4th of July 1975 (the 200th anniversary of THE shot heard round the world).

But I not sure what any of that, nor your answer, has to do with answering the question.   ::)

So I will add to the discussion by asking, "Does accuracy NEED to be improved?"  

Some would say that if the round lands in the safety zone it's accurate enough.  (I have had them caught in the wind and land BEHIND me.)  But that was Iowa, not Boston.

Tim K                 www.GBOCANNONS.COM
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U.S.Army Retired
N 37.05224  W 80.78133 (front door +/- 15 feet)

Offline Victor3

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Re: Improving Accuracy of "Tin Can" Mortar Projectiles
« Reply #114 on: April 12, 2010, 11:12:04 PM »
 CW - Not to but in, and I'm sure Tracy will answer later, but as far as my experiment goes...

 I had one stabilized projectile, five packed aluminum wads and several 80 grain charges weighed up. I was hoping to be able to fire all five to see if my projectile would hit near the same spot on each shot and observe the stability of the projectile in flight. Unfortunately, the 1st shot damaged the projectile beyond repair.  :'(

 I also had a six-pack of ice filled aluminum cans on dry ice in a cooler to shoot after the SMACK projectile testing was done, in order to observe how close an un-stabilized bunch of projectiles would 'group.'

 I know the above isn't very scientific, the ice cans being a different weight than the stabilized soup can and all, but I figured it would at least provide some form of rough comparison. It was the only stuff I could come up with at short notice, one day before we could get out to play.

 On my SMACK projectile, what I was hoping to see was it leaving the bore straight and staying that way through its flight, not unlike a modern mortar round. That didn't happen, but it did stabilize quite a bit before it hit so it was at least a partial success.  :)

 Would it have proven any more accurate than my ice cans if I could have completed all test shots? I think so. With modifications to the design of the wad and/or projectile, I'm fairly confident that it will.

 As to your question "Does accuracy NEED to be improved?"

 No, not really. But if I could set my mortar up near a field full of ground squirrels, laser the range of one and scare the poop out of him by getting very close on the 1st shot, it would be fun...
"It is a capital mistake to theorize before one has data. Insensibly, one begins to twist facts to suit theories, instead of theories to suit facts."

Sherlock Holmes

Offline seacoastartillery

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Re: Improving Accuracy of "Tin Can" Mortar Projectiles
« Reply #115 on: April 13, 2010, 05:58:04 PM »
Tracy -  I've enjoyed many fine meals in the fair city of Boston.  None in the plural past perfect tense, though.  And it was a few miles down the road, a bit past the bridge between Lexington and Concord, past Waldon Pond over in the township of Harvard (not the University) on the South ranges of Fort Devens where I fired my first mortar for the first time.  It was using a water-filled Coke can and was on the 4th of July 1975 (the 200th anniversary of THE shot heard round the world).

But I not sure what any of that, nor your answer, has to do with answering the question.   ::)

So I will add to the discussion by asking, "Does accuracy NEED to be improved?"  

Some would say that if the round lands in the safety zone it's accurate enough.  (I have had them caught in the wind and land BEHIND me.)
But that was Iowa, not Boston.  


     Tim, I know the area of the bridge quite well, returning for a second time in 2008, Mike and read ALL the signs and learned quite a bit.  The British troops suffered mightily on that long march, from the bridge all the way back to Boston.  I can't match your historic Ft. Devens story, but I was chased by wild boars across several artillery ranges at Ft. Polk in 1970 while on a 250cc Yamaha trials bike.  Does that count?  Tim, we think that our accuracy does need to be improved, especially when 'soup-can' mortar projos are being shot.  What others choose to do is their business.  We will try to answer your most pressing issue with our first, limited test of the S.P.L.A.T. projo, that of not having a statistical sample from which to draw conclusions or a standard data set against which to compare the "improved" version.  In three or four weeks we will do a more complete series of experiments.  The standard will be the dispersion of 5 rounds consisting of asparagus cans filled completely with cured concrete and the dispersion associated with a single S.P.L.A.T. fired five separate times.  Let's be clear here, we probably won't convince one shooter to change their projectile choice, we're just having some fun doing these experiments, that's all.

     Tim, you are just a calm, unhurried and thoughtful guy, exactly the type of person we feel comfortable shooting with.  We are finding it really hard to imagine an artillery projectile we fired landing BEHIND us!   :o :o   Maybe Colorado winds are puny next to those blowing through the cornfields of Iowa!  Yikes!

    
CW - Not to but in, and I'm sure Tracy will answer later, but as far as my experiment goes...

 I had one stabilized projectile, five packed aluminum wads and several 80 grain charges weighed up. I was hoping to be able to fire all five to see if my projectile would hit near the same spot on each shot and observe the stability of the projectile in flight. Unfortunately, the 1st shot damaged the projectile beyond repair.  :'(

 I also had a six-pack of ice filled aluminum cans on dry ice in a cooler to shoot after the SMACK projectile testing was done, in order to observe how close an un-stabilized bunch of projectiles would 'group.'

 I know the above isn't very scientific, the ice cans being a different weight than the stabilized soup can and all, but I figured it would at least provide some form of rough comparison. It was the only stuff I could come up with at short notice, one day before we could get out to play.

 On my SMACK projectile, what I was hoping to see was it leaving the bore straight and staying that way through its flight, not unlike a modern mortar round. That didn't happen, but it did stabilize quite a bit before it hit so it was at least a partial success.  :)

 Would it have proven any more accurate than my ice cans if I could have completed all test shots? I think so. With modifications to the design of the wad and/or projectile, I'm fairly confident that it will.

 As to your question "Does accuracy NEED to be improved?"

 No, not really. But if I could set my mortar up near a field full of ground squirrels, laser the range of one and scare the poop out of him by getting very close on the 1st shot, it would be fun...

   


     Victor,  If you have the time, I am one guy who would love to see further experiments in the pursuit of excellence regarding your SMACK projectile.  I realize that time is sometimes very difficult to find in our modern world.  I'm sure that a resourceful fellow such as yourself can make the revisions to the drawing that are needed and should have no difficulty getting all the signatures that are required.  AND, controlling the production dept. as you do, all it takes is an order like,  "Sunday?  What is it about about Sunday work that you don't like?  If you haven't changed your mind by Friday at 3 PM, come in to my office; I will tell you all about an  'Alternative to Gainful Employment'  that you are free to pursue."  It's not easy to keep a small business afloat, but the Freedom from situations like I just described, and have personally faced, is Stunning.  

     If I were a 'down-range' ground squirrel, I would be very wary of your activities!   :o

Tracy
Smokin' my pipe on the mountings, sniffin' the mornin'-cool,
I walks in my old brown gaiters along o' my old brown mule,
With seventy gunners be'ind me, an' never a beggar forgets
It's only the pick of the Army that handles the dear little pets - 'Tss! 'Tss!

From the poem  Screw-Guns  by Rudyard Kipling

Offline Cat Whisperer

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Re: Improving Accuracy of "Tin Can" Mortar Projectiles
« Reply #116 on: April 14, 2010, 01:36:56 AM »
Tracy -

Thanks, good thorough answers.  (I ran across an article on round ball mortar accuracy last night by U in a reprint from the Artilleryman.)

As one of the folks out there on one of the cast bullet boards says, "extremism in the pursuit of accuracy is no vice."

Yes, the wind blows in Iowa.  Comes racing down from the Colorado rockies, picks up speed across Nebraska (where the ONLY thing slowing it down is a two-strand barbed wire fence - and one of them is broke) then into Iowa.

Knowing what is more, or less, accurate allows us to improve - insted of repeating mistakes or wandering.  I've shot LOTS of bullets in order to get 10 on paper, when I should have been working on improving accuracy.

Tim K                 www.GBOCANNONS.COM
Cat Whisperer
Chief of Smoke, Pulaski Coehorn Works & Winery
U.S.Army Retired
N 37.05224  W 80.78133 (front door +/- 15 feet)