30mm info by General Dynamic


#1







#2

hello
i see that general dynamic made steel case for 30x113 rounds
i would know if the m230 chaingun on apache helico can fire the french steel case 30x113 defa and the british brass cased 30x113 aden ?
thank for your responses


#3

I am not certain, but possibly…the following extracts from Jane’s Ammunition Handbook demonstrate the complexity of the ammunition interchangeability issue in this calibre:

…and:

…and just to show that not all Aden ammo is brass-cased:

…and the situation with the US ammo is becoming even more complicated, with the development of a percussion rather than electric-primed ammo:


#4

What do they mean by a “high radiation environment”? The electronics on the Tiger helicopter suggests radio frequency radiation. Then they mention the nuclear aircraft carrier, which suggests ionising radiation. How does this affect the primer? I can understand how electromagnetic fields may affect an electric primer, but what about ionising radiation?


#5

The primary issue is electromagnetic. There is even an acronym for it: HERO - Hazards of Electromagnetic Radiation to Ordnance.


#6

Modern warships produce a lot of electromagnetic radiation. I understand that the electric-primed 20x102 Vulcan Phalanx CIWS ammo has the base of the cartridge protected in some way from such radiation while on the mounting. Not sure what they do with the Hornet’s M61A2 ammo.


#7

Tony, the Phalanx CIWS loading links have a portion in the rear bent inwards covering the primer and sowith protecting it. I assume the magazine drums on CIWS as well as on the F-18 have an organic EMR protection.

Most weapons containing electronics (like guided bombs, missiles etc.) also have an organic EMR protection.

Actually the dramatic increase of EMR in military equipment in particular in ships and aircrafts led to the development of so called passive target aquisition unlike in old days where targets were detected by active systems sending their radio waves. Today it is easier to find targets by their EMR rather than letting the whole world know that one is sitting in his radar station waiting for a HARM missile to put an end to his attempts.
Some people said that this was also the reason for the loss of a US F-117 in 1999 in Kosovo (at that time part of Yugoslavia) which was using one of the first eastern passive target aquisition systems. I wonder if we will ever get to know what really had happened.


#8

What is organic EMR protection? Paint?


#9

Copper sheet liners for example (very thin ones).

Paint may be also an option if they manage to add some of the metallic powder required for this. Maybe they did already?


#10

What frequency range would copper sheets cover? all the way up to sub millimeter?
Soren


#11

Thanks for clarifying that. When they said “nuclear powered” it also seemed like they were implying that ionising radiation was a problem.


#12

[quote=“mausernut”]What frequency range would copper sheets cover? all the way up to sub millimeter?
Soren[/quote]

Soren, I never followed that in detail. I guess they cover the frequency range in question for negative influence. Maybe somebody more into this may help us out.