300 lb Triplex Rocket

[rickshaw]

Calibre measures are invariably taken from land to land across the tube of a barrel (from groove to opposite groove, for laymen). 

Lands are the raised portion of the rifling, grooves are the valleys.  You do mean groove to groove?

Really?  And there I have been working on the other assumpation all these years.   

[Mr.Creak]

Really?  And there I have been working on the other assumpation all these years.

Yup.


But it gets worse...

Calibre measures are invariably taken from land to land across the tube of a barrel

Thus:

In a rifled barrel, the distance is measured between opposing lands or grooves; groove measurements are common in cartridge designations originating in the United States, while land measurements are more common elsewhere.

Wiki: http://en.wikipedia.org/wiki/Calibre.

I came across much the same problem when "investigating" guns (for my wargame rules). They're listed by calibre and calibre length and I ran into a couple of WWII Russian guns that appeared to have two calibre lengths for exactly the same model number. It turned out that some nations use the grooved portion of the barrel only in such a calculation and others include the length of the chamber. And, being insufferably pedantic thorough, I'd checked as many sources as possible only to find that different sources use different methods.
Ho hum... 

[Old Wombat]

But if you were in the target area would you want to rely on that? I think not, you'd be getting the H**L out of there! 

H*!! no!

That was the whole point of them, like their ground-based equivalents (such as sweet "Katyusha"), they were a terror weapon.

No matter where the d@m^ things were pointed when launched, they could hit almost anywhere!

[NARSES2]

Interestingly there was a 7.2" Burney gun which used a squash head type round. Wonder if they were these rounds or standard 7.2" shells ?

[rickshaw]

Interestingly there was a 7.2" Burney gun which used a squash head type round. Wonder if they were these rounds or standard 7.2" shells ?

Burney developed his own HESH rounds.  His guns also fired standard HE rounds (which is why he used existing calibres).  The HESH rounds were much longer and less streamlined than the standard HE rounds (and 'cause they had very thin walls, carried considerably more HE filling).

[rickshaw]

Its taken me a long time to track down the dimensions of the 7.2in HE round.

*Length (less fuze)*   35.07 inches
*Calibre radius head*  5/10
*Body Diameter*        7.185 inches
*Driving Band Diameter*  7.47 inches
*Weight (incl fuze)*    202 lbs
*Explosive Weight*     28 lbs

[Go4fun]

As a TOW (Tube Launched Opticaly Guided Wire controlled) missile weapon operator in the U. S. Army I can tell you any missile has the ability to go haywire and land anywhere, including on top of the launcher.  
When it goes off track and starts climbing, you run!

[Mr.Creak]

Current progress:


That nose doesn't look right, but I'm having problems sorting out the CRH geometry.
Any particular scale you want it?

[Go4fun]

I quote Mr. Creak: "What if... I had a brain?"
I think you do and don't realize the shear magnitude of your WhIffery talents.
Andy

[Mr.Creak]

Ha!
Many thanks but...
I'm a  design engineer by profession (actually it's a trade - poncy architects draw stuff and THAT'S a "profession" - ho hum  ) - what used to be called a draughtsman.
This sort of stuff is workaday for me (although the curves on aircraft are not what I'm used to, simple stuff like this is relatively simple).
It's my intention (ambition?) to work through BSP Hypersonics and Vulcan's Hammer and produce drawings of all the juicy stuff that got (or should have been) hung under wings to go bang.
The good news for anyone wanting copies is that (in true industry manner) I draw them full size and can scale to whatever is required - watch this space.
Requests will be considered - I feel more "urgency" if I'm doing things for other people rather than for my own benefit.

[Gondor]

The wonders of AutoCAD and vector line drawings

Gondor

[Mr.Creak]

The wonders of AutoCAD and vector line drawings
Gondor

Wait 'til I get my solid modeller package working.
AutoCAD (in my professional opinion) is a POS.