Something else i've been working on .

[PR19_Kit]

My knowledge of artillery starts and stops with British Army 25 pounders, which could and did fire at quite high angles, thus being called gun-howitzers in some circles. I only ever fired one at almost point blank range using a scope sight though. 

That sounds like your next article for the Newsletter Kit! 

Gondor

Hm, now that's an idea. 

I hadn't thought of that bit of my life in Newsletter terms.

[rickshaw]

Are heavy mortars rifled ? If so then I suppose the main difference between them and a howitzer is the weight of projectile and range ? If they aren't rifled then I suppose they are less accurate then a howitzer ?

Chris

The classic definitions are:

Gun - fires usually at a maximum elevation below 45 degrees and has a barrel at least several calibres long.
Howitzer - fires at a maximum elevation above 45 degrees and has a barrel at least several calibres long.
Mortar - generally fires a light, thin walled shell from a short barrel and has a maximum elevation up to 90 degrees.

Nowadays, Howitzers and Mortars cross over a lot.  Heavy mortars can often be breech loaded, like howitzers and be rifled, but what they generally retain is the large capacity, light, thin-wall shells.  Howitzers tend to fire heavy, artillery style shells.   Both mortars and howitzers have high trajectories, having been originally designed to fire over obstacles, usually into fortifications.

Guns however still tend to have long barrels, low trajectories and thick walled shells.  They can be either rifled (most artillery) or smoothbored (tank guns).  Gun/Howitzers cross into howitzer territory and have higher trajectories than normal guns.

[PR19_Kit]

Mortar - generally fires a light, thin walled shell from a short barrel and has a maximum elevation up to 90 degrees.

Hmmm, using the maximim elevation presumes that the mortar crew have a VERY fast means of escape I guess? 

[NARSES2]

Cheers Rick'. It's what I thought, but it's always nice to actually know 

[Rheged]

Mortar - generally fires a light, thin walled shell from a short barrel and has a maximum elevation up to 90 degrees.

Hmmm, using the maximim elevation presumes that the mortar crew have a VERY fast means of escape I guess? 

This reminds me of a local joke in my former county.
Many Cumbrians  make "Millom" jokes.  e.g.  "The Millom T A  mortar team who fired a round in the air.......and missed"

[NARSES2]

 

[rickshaw]

Mortar - generally fires a light, thin walled shell from a short barrel and has a maximum elevation up to 90 degrees.

Hmmm, using the maximim elevation presumes that the mortar crew have a VERY fast means of escape I guess? 

Well, in practice the shell will not actually return exactly to where it was launched from, because of the vagaries of air currents, etc.  I've only ever heard or seen pictures of mortars used at that sort of elevation once - during the Commando raid on Vaagso.  There's a famous picture of a 3in mortar firing directly upwards, in an effort to hit a house just the other side of the street.   However, it could be used I suppose for "danger-close" shoots if the situation was such that it was deemed necessary.

Here's a trick question for everybody - what calibre was the British 3in Mortar in WWII?   

[PR19_Kit]

Here's a trick question for everybody - what calibre was the British 3in Mortar in WWII?   

I'll bet it WASN'T 3", if only because you asked. 

[Steel Penguin]

   ive had a quick look and get 76.2mm ( my copy of Janes infantry weapons 90-91) but I think that's for the bomb dia, the barrel dia is 81.5mm ( but with a Mk5 barrel)

[PR19_Kit]

76.2 mm IS 3".........

81.5 mm = 3.21" however.

[Old Wombat]

http://en.wikipedia.org/wiki/Ordnance_ML_3_inch_Mortar

[Steel Penguin]

so I was right    that's a turn up for the rare!
the bombs that much smaller to allow it to muzzle load and drop down the barrel,  on a more modern bomb there will be a "plastic" ring that will push out on ignition to seal the "windage" gap around the bomb, costs slightly more per round, but makes the round far more accurate.

[rickshaw]

Yes, the 3in was 81mm in calibre.  Sorry, I'd forgotten I'd asked the question.   While the original Stokes Mortar, on which the WWII 3in was based, was in fact about 79mm in calibre, by WWII it had grown to 81mm to prevent bombs being caught on their way down.   I've used 3in mortars (just on their final way out in Australian service in 1980!) to fire 81mm mortar ammunition and vice-a-versa.  In WWII, there are numerous examples of either side firing the other's ammunition after they'd captured stocks of it.

And I've alluded to the reason why the barrel calibre was substantially larger than the bomb's calibre - to make sure it would slide down the barrel.  The result was quite a "leaky" bomb, with considerable propellant gases leaking around the bomb as it went back up the barrel but that was made up by simply adding more propellant bags wrapped around the stem of the tail.   I've still seen though, the occasional bomb caught in the barrel.  They have a special extractor and a special drill to remove such bombs.   Still quite scary, though.