the plan was for local production.  However, this never eventuated for reasons that aren't at all clear but still seems to rile some people.

Regarding highlighted, 

That 2500 EFC is a valid number or therabouts for most 155mm tubes, however its important to note that that number is a "Fatigue" value for the life of the tube.  The primary criteria for condemnation of tubes is wear, if you are shooting the current top charges you are going to hit wear condemnation criteria a long time before you have fatigued your tube. 

 

Regards

 

Arty

Wouldn't disagree with that, I've never come across a artillery barrel being condemned for fatigue.  Since 52 cal has more powerful max charge than used with 39 cal  this means that its max charge should have a higher EFC value.  Therefore hoping to get the same barrel wear life as a 39 cal barrel seems a bit optimistic.  Of course this makes assumptions about the nature of the propellant, particularly its burning temp, eg are modular charges basically single base or triple base?

Definitely not precise recall from me, but IIRC it was a political decision focussed on minimising expenditures...  plus there might have been some political push to trade off against other ammo sellers such as the sth koreans...

But doesn't some of that have to do with the actual manufacturing techniques used in the barrel?

 

Build a 52-cal tube with modern metallurgy,

and compare that to a 39-cal tube built with 1950s or 1960s era metallurgy knowledge,

and I'd still be willing to bet that the newer gun tube,

even with higher pressures and temperatures,

will last longer.

Plus, as was mentioned, consider the chemistry of modern propellants as compared to powder charges designed a few decades ago (or more).

 

And perhaps even different modern alloys (even plastics?) allowing for softer driving bands and seals around a shell that don't wear out the gun tube as fast, either...?

I am no artillery man, but as I understand it, ADF bought the "L118" barrels and Abbot ammunition in case of war. We use the L119 configuration and the old (but cheap and plentiful, if rather limited in range) 105mm ammunition that we used on our earlier M2A2/L7 guns for all peacetime training activities. An American type, from what I understand, but as I said, I'm no artillery man.

Anyway as we have never taken the guns on an operational deployment the barrels are still in their delivery packing...

I have it on good authority from 2 different sources that at least 4 Field and 1 Field are actually equipped with the longer barrels, but simply don't use them on cost grounds.

I don't know which information you are calling "dodgy", but if it relates to what I said what I was getting at is that (to my understanding) there are no PGM's available for the Light Gun like there are for 120mm mortars or 155mm guns. The improvements to the type will allow it to undertake current missions better, but unless Australia want's to develop its own PGM's the type is strickly stuck on an evolutionary rather than a revolutionary development path.

 

If that's all the Pom's want to achieve then upgrading the Light Gun is probably the cheapest way to do it. However, I can certainly see the benefit in having a 30km+ PGM capable M-777 155mm battery supporting every Austrialian Army battalion. The potential to support troops at extreme ranges and to reduce ammo usage due to increased accuracy would be well worth the investment, IMHO.

 

Regarding base bleed ammo for the 105mm, my understanding is that it has been tested but not adopted by the British Army. I don't know whether it was to do with cost or problems with the ammo, but that is what I have read recently anyway. Happy to hear any updates on it though.

 

Finally, what I was always told about why we didn't licence produce L-118 ammo is that the Pom's either wouldn't give us a production licence or at least not on sufficiently favourable terms to justify it. It would make sense.... why would they give up monopoly production rights to that ammo system? Anyway, the L-20 ammo system for the L-119 has served us well enough for training, so it isn't a big drama. I believe the US has come up with some good upgrades for that barrel to, including a 19km capable RAP.

 

As I understand it the last 105mm Fd Mk2 was expended about 5 yrs ago (give or take) by 23 Fd Regt, and as I said there was only 15,000 rds procured.  If DoD wanted to produce ammo they could have done, an article in Cannonball last year by the former project manager for Hamel made it quite clear that local ammo production was always the plan but couldn't explain why it was dropped.  The stuff about the UK IP owner being difficult is nonsense, they'd have done a deal, but like any manufacture of relatively modern ammo there would have been royalties (105mm tank ammo production licensed from the same source?).  Of course the royalties might have been greater if Aust had exported it, IP owners get funny over things like that.  It's called capitalism, even if the Peoples' Republic of Pucka don't like it ;-)

 

Technically, the 1935 pattern ammo (as the Light Gun General Staff Requirement called it, AKA 105 mm How in official UK parlance or M1 type if you want) is semi-fixed while while 105mm Fd, like 25 pr, is separate loading which permits a larger chamber without having a larger cart case not to mention different carts for top charge using a slightly different propellant.  Semi-fixed has the advantage of faster loading, it's a matter of opinion whether or not this is worth the disadvantages.  Of course the other advantage of 105mm Fd is its greater lethality, and a whole heap more with the new shell.  And that's what its all about.

 

Whether or not PGM or semi-smart will be developed for 105mm Fd is unclear.  The real problem with all assisted ammo without any smarts is the dispersion, large, and clearly not suitable for danger close, which is popular at the moment.

 

155mm 52 cal barrels seem to be chromed as standard, and I think this has long been US practice with 39 cal but not neccesarily by other nations.  Chroming does increase barrel life but my understanding is that there is still a problem with 52 cal.  The only currently known way to reduce barrel wear and extend barrel life is to have cooler gas against the chamber and barrel wall.  This is what the S African charge design did and the results were fantastic, no need for expensive barrel chroming and very long life.  Problem was their failure to meet insensititive ammo regs.  As I said in a previous post, without knowing what propellant is used in modular charges it's difficult to assess the problem.  However, its usefull to remember that the US traditionally uses single base prop and this is a bit hotter burning (hence a bit higher rate of wear) than the triple base used by UK and Germany. 

 

As for M777, the interesting question is why did UK reject it (and Caesar) in their trials.  No doubt some will say budget pressures but if they were really wonderful the benefits would have outweighed this.  My theory is they've woken up to old truths, M777 has a crap rate of fire and neither of them were much good for fast and wide traversing, which is proving essential in Iraq and has probably jogged folk memories.