angle for mortor,

[rampa room artillery]

what is a good angle for a 24 lb mortor??
 i think i am going with 50 degrees

[Terry C.]

Coehorn?

I think standard is 45°. That's what I designed mine around, and I think they look good at that angle.

The GB mortar sled base is adjustable, but it was built to be 'neutral' at 45°. The quarter-scale is on a bed base and is fixed at 45°.

[Cat Whisperer]

Having not MEASURED any originals, 45 degrees is oft spoken as being the standard.

Having one that I can adjust, let me say I've run everything from about 15 degree elevation (mortar slides back 2-4 feet) to 89.9 degrees.  (You've got to really have a good eye for that and KNOW which way the wind is blowing.)

43 point something is the best for max range for modern pointed projectiles that are rifled, which is a little different than for spheres.  (Known as the dividing point between shooting at 'low angle' and 'high angle' in modern artillery.)

Since I shoot on many 100 yard ranges I like shooting high angle - fun to observe the round lazily flying through the sky and doing massive toll on branches of trees in the impact area.

[Double D]

From  The Artillerist Manual by Gibbons

In mortars, the usual angle of elevation is 45º, generally a little less; and the charges vary
according to the distances.

[Artilleryman]

In current competition the idea is to have the shell end up as close to the stake as possible.  We usually fire our 8 inch at 50 degrees.  We do this because we like to use a main charge without adjustment charges.  By starting at 50 degrees we can reduce the elevation to get more range or increase the elevation to decrease the range.  This is relatively easy since the 8 inch has adjustable elevation.

On a historical note, what we are doing does not match up with what they did historically.  We are trying to get the shell end up as close as possible to a stake.  They wanted the shell to explode several feet above the ground and spread fragments through the target area.  The lighter weight shells had the advantage of not burying in the ground and could still do damage when they exploded.  The advantage of the larger shells is the accuracy at longer ranges and heavier fragments.  In both cases close was good enough.

[Terry C.]

When I used the golfball mortar to shoot for BINGO at 50 yds., I probably could have gotten better results with the elevation cranked up a bit.

Unfortunately, my location (pecan orchard) limited the trajectory of the balls. If I tried to increase the elevation more than a degree or two past 45°, the balls would get fouled in the overhanging limbs.

The GB mortar sled was designed to have an elevation range of 35°-60°, with 45° being neutral (elevator screw perpendicular to tube). Because the finished elevator was bulkier than the original design, it doesn't screw down quite as far, giving a minimum elevation of about 37.5°.

I've never fired it at that low elevation, I need to try it just to see what the effect on trajectory would be.

And, well, just to make some noise. 

[lance]

 one of those BINGO games, i could have gotten better results if my Dictator would have stayed locked in place. It's my fault for having too much fun to keep a eye on the angle.

[Rickk]

If you aim for 45 degrees, and are off by a degree, the resulting error in impact location is smaller than if you are off by a degree from any other angle.

[Blaster]

I have a hunch that I shouldn't put my 2 cents worth in on this subject but The South Bend Replicas folks recommend, "Elevation of 60 - 70 degrees is best".  Perhaps this applies to only the mortars that THEY sell ??.

[Cat Whisperer]

I have a hunch that I shouldn't put my 2 cents worth in on this subject but The South Bend Replicas folks recommend, "Elevation of 60 - 70 degrees is best".  Perhaps this applies to only the mortars that THEY sell ??.

It all depends on how one defines the term "BEST".

Most accurate?

Greatest range?

Aesthetics?

[Blaster]

OK Tim, I understand what you are saying.  Perhaps SBR was just giving those figures if the shooter would want to kinda average all three things out to one elevagtion.  Like accuracy, range and aesthetics.  Thanks.. Blaster (Bob in So. CO)

[lance]

 This is from South bends catalog :   There is no point in firing a mortar projectile beyond readily observable range, since observing it's descent to a given ground mark is the very point of target use, elevation of 60-70 degrees is best.............. ya'll know me, i like to try lot's of angles

[Cat Whisperer]

I will NEVER forget shooting on a 100 yard range with the barrel down at about 15 - 20 degree elevation - a little low for the mortar - shooting a 7-1/2 pound concrete filled 4.5" pvc pipe section.

It hit a 2-3" tree - it looked like the cartoons as it bent back and flung the round to a tree on it's right - which bent and flung it to a large tree on the left -  hitting it with a thunk!  There I was jumping up and down yelling in excitement - and everyone with me MISSED it!  NO WITNESSES! 

Maybe I should build a large-bore howitzer next?

[lance]

Maybe I should build a large-bore howitzer next?

can we play BINGO with it?

[Cat Whisperer]

Maybe I should build a large-bore howitzer next?

can we play BINGO with it?

Of course! 

It's about time I built something that had a focus of being an ACCURATE shootin' iron and not just a way of "PROPERLY" disposing of tin cans.

[phalanx]

I sure wish i knew more about this ,it is interesting to read , and how you guys can put a round ,falling out of the air in an arch right on target ? It must take a lot of practice.

[Cat Whisperer]

It's easy in concept.

Do the same thing every time.

[phalanx]

Cat i would mess it up and kill my cow.
When these things come down ,what is vertical descent ? 33fps x2 per 33 feet ?
So a ball that weighed 10 pounds from 200 feet ?  Ouch.
Its possible for this thing to hit with one ton of force.
Man that would really mess up my hair 

[phalanx]

Ok Cat: you have figured out your angle , i assume as to a known trajectory, That would mean you would need to stay with one certain load ,and projectile weight ?
If you moved the Mortar,in setting it up again would you need to measure the distance again?
Or is there a chart or rule of thumb in which you can change the angle in order to remain on target ?
I am sure you don't fire for effect do you ?
OK mortar guys stop laughing ,if i knew i wouldn't be asking .
Mortar guys ,they eat everything in the chow hall ,and they never make their bunks.

[Cat Whisperer]

Phalanx -

You ask a LOT of hypothecital questions.

If you're serious about learning about mortars and/or cannons come over and we'll spend a day or an afternoon - Lance & I need to get together for another shoot soon anyway.

I don't mean to put you off, but you need to see and do these things first hand.

[phalanx]

Oh i shoot cannon ,i just never messed with a mortar ,sorry i was asking.
Once  i get this photo thing down i will show you cannon.
62 Chevy Bel air,picked up off the ground ,and set back 10 feet.
Smacking a computer at 300 yards,at a Cowboy shoot.
Grape shot,44 cal ,where nothing grows,moves,or crawls for 50 yards.
Something i didn't think was proper for here,it takes away from the sport.
Commencement ,firing a blank while old glory is raised ,at a new building.
I only asked you about how to angle a mortar ,isn't that within the scope of the forum?
Some members here know i shoot these guns ,one has seen them,and fired them.

[Double D]

Phalanx,

Tim is offering to take you under his wing and guide you into the next level of black powder motar and cannon shooting!! He ain't putting you down, relax and enjoy.

Okay so I am lying. He really is only tring to find somebody to help carry his mortar...but you will enjoy it, when the hernia heals. 

[phalanx]

He insinuated i know nothing about Cannon.
Oh i guess the last 12 years ,at numerous shoots ,Cowboy & Civil War re-enactments,County Fairs,and people who are members here who have meet me and seen & shot my guns and asked me to come here means nothing ?
All because i asked him about Mortars ? Is this how students here are treated ?

[GGaskill]

Is this how students here are treated ?

I think you are going to have to grow a little thicker skin.  One of the deficiencies of email and forum posts is the lack of body language to convey additional feeling to a thought.  Most people do not imply ill thoughts, they express them explicitly; so if you don't see an explicit insult, don't interpret it as one.

[phalanx]

OK ? I asked about a trajectory?
I did all this wrong by asking that?
I am treated as a Dufus because i ask ?
I will only talk to DD on this!!!!
He doesn't insult me,we made a sort of peace because he is a stand up guy.
He may delete one of my post ,but he tells me it was him ,and why he did it.
He asks my opinion ,and wants to know what the old guys knew.
And he keeps it off the board ,me and him, I like that.

[Cat Whisperer]

Ok Cat: you have figured out your angle , i assume as to a known trajectory, That would mean you would need to stay with one certain load ,and projectile weight ?
If you moved the Mortar,in setting it up again would you need to measure the distance again?
Or is there a chart or rule of thumb in which you can change the angle in order to remain on target ?
I am sure you don't fire for effect do you ?
OK mortar guys stop laughing ,if i knew i wouldn't be asking .
Mortar guys ,they eat everything in the chow hall ,and they never make their bunks.

Phalanx -

I may be reacting to your style.  My intent is certainly not to insult anyone.  But reading through your posts, you have put out a LOT of questions that just don't sound like you've thought through any of this.  They are interleaved with personal questions and statements that really cause me to wonder about your real intent.  I say this not from just my own perspective, but from others that have sent PM's, emails and telephoned me about you.

[phalanx]

My intent was to ask you about a Mortar .
I am sorry you envision it as something else.
And you are not alone in the respect that you are receiving Emails from some of the members.
 

[dominick]

Quote from Cat Whisperer, January 6, 2007
 
Having not MEASURED any originals, 45 degrees is oft spoken as being the standard.

 The 45 degree standard goes back to days of Nicolo Tartaglia [professor of mathematics at Venice] who during the Mid 16th Century wrote his "Three books of Colloques concerning the Art of Shooting"  He pointed out that the maximum range of a gun would be achieved at an elevation of 45 degrees. In 1646, a man named Francis Malthus recommended a method of aiming mortars which was to remain in favor until the mid-19th century.  This involved placing the quadrant on the face of the muzzle.  A shot was fired at an angle of 45 degrees with a first charge.  If the shot over-reached the objective, he modified the guns elevation to a steeper angle.  If, at an angle of 45 degrees, the shot fell too short, the charged was increased.   

In the early days of artillery prior to Tartaglia, and for sometime afterward, it was believed the a cannon projectile traveled in a perfectly straight line to its maximum range, then stopped and fell straight to the ground.  Mortars were believed to have a three piece trajectory, were the ball traveled in a straight line under the effect of the powder [motus violentus], then 'arc'd, the short arc effect of the powder wearing off [motus mixtus], and then the ball fell straight to the ground [motus naturalae].   Dom

[Cat Whisperer]

So is it theory, longstanding theory? 

THANKS for the history behind it!

Or, with a smooth bore and spherical round, is it only ABOUT 45 degrees.

I know, may have said this before, that with rifled modern artillery rounds the angle is near 43 degrees - for what ever the reason is - don't remember all the physics behind it.

Has anyone shot several rounds at 45, taken the mean, repeated at say 40 and 50 degrees and compared the average ranges?

[dominick]

Cat, I wouldn't know for sure if it was longstanding theory or if it was approximate, or exact, and probably nor would anyone else.  The problem back then was, when something was written to explain a discovery or new theory, the knowledge seldom went far as the illiteracy rate among the lower ranks of the military [who were just common folk] was high. This valuable information, was passed down to them word of mouth and in some cases, they either received the information incorrectly or never received it at all.  Also, The author in many cases only wrote one original and it may have only been copied a only few times.

I have not,  nor do I know anyone who have  seen or read a copy of the handwritten documents written by these people, and like many ancient documents, can be translated and/or re-written incorrectly.  The problem with historical documentation is that sometimes it is very difficult or very expensive to locate and view the original if one such document would be fortunate to exist today.  So instead, we rely on what has been passed down by historians, researchers and others which is the best method we have.  So I view all "historical truths" as tentative truths subject to change if new information is found that warrants change.   The genuine intent of the author is sometimes lost forever.  It would be the same difficult if not impossible situation for someone to accurately answer the question, who invented black powder?  Dom