Mrsi In Actual Operations

[lastdingo]

Modern guns have muzzle velocity-measuring radars. Armies discover inaccuracies and associated risks with such radars that they wouldn't have known about before.

[nigelfe]

Rubbish. Many armies have been calibrating their guns for decades. The British field artillery started in WW1, their coast artillery and navy a few years earlier. MV radars were introduced for calibration in the 1960s. The Britsh started fitting them to every gun in the early 1980s.

 

However, these radars only measure MV, this is only one of the 'local' variations. Charge temperature also affects MV and varies almost by the hour. Then there are the meteorological effects throughout the trajectory that effect shells in flight. These also vary continuously, this is why NATO standard meteor messages are produced (typically every two hours) and the data used in the calculation of firing data.

[lastdingo]

Rubbish. Many armies have been calibrating their guns for decades. The British field artillery started in WW1, their coast artillery and navy a few years earlier. MV radars were introduced for calibration in the 1960s. The Britsh started fitting them to every gun in the early 1980s.

 

However, these radars only measure MV, this is only one of the 'local' variations. Charge temperature also affects MV and varies almost by the hour. Then there are the meteorological effects throughout the trajectory that effect shells in flight. These also vary continuously, this is why NATO standard meteor messages are produced (typically every two hours) and the data used in the calculation of firing data.

 

Rubbish.

The predecessor guns of the PzH 2000 had no MV radar and weren't built that much for low dispersion either.

 

And what else you mentioned was immaterial to what I wrote.

[nigelfe]

Actually, it was never suggested that the Bundeswehr had MV radars on their guns pre-Pzh2000, but thanks for confirming that they did not. The point being made was that some armies did and had done so for many years, and hence Pzh2000 doing so was not novel, merely following what others had already done. Ie the German Army was catching up with others.

 

You can't really build guns for low dispersion because range dispersion is caused primarily by round to round variation in MV, and this is a function of ammunition quality control (ie the manufacturing tolerances in the propelling charges and the shell weight and dimensions). Dispersion does increase as the barrel wears, but the tolerances in barrel manufacture are very small, and presumably decreasing as computer controlled machine tools have improved since the 1960s. I would assume that the tolerances in Pzh2000 barrels are about the same as AS90.

 

As for my other comments, I'm merely giving the bigger picture about factors affecting accuracy. It's no use pretending that they don't matter, they do. You have to consider the whole matter systemically, not cherrypick points. Or perhaps it's just ignorance of all the key aspects of artillery.

[lastdingo]

Of course you can build guns for small dispersion, just as you can build sub-MOA rifles.

It's been done with heavy artillery since the 1920's at the latest.

 

This merely gets neglected in the literature because the gains to be had over other guns are smaller than the errors caused by MV.

Tolerances for spin and projectile mass affect dispersion as well.

This shows some causes of dispersion, particularly those which can be calculated with external ballistics formulas:

http://www.mtc.edu.eg/ASAT13/pdf/FM03.pdf

 

Others exist as well, such as barrel vibration, barrel bending, barrel temperature, muzzle brake effects etc. And some of those can be reduced by design.

[nigelfe]

All gun designers try to optimise, the technology is well understood. Of course SP guns are easier to deal with because barrel weight is less of a concern than it is for towed guns. And performance does improve as designs develop, for PE an excellent example of this in the c.1960 design barrel used for Abbot and the one not too many years later for light gun, both 105mm, both firing the UK pattern 105mm, but much improved dispersion with light gun.

[Mr King]

https://www.youtube.com/watch?v=PWDylZGodLs

[lastdingo]

Wow, they're incompetent beyond belief.

[Chris Werb]

Words fail me. WTF? on SO many levels!