Tuesday, March 08, 2005

Speculation on WZ-10 chain gun.

some great exchange conducted by D6 and Henry Yeh



First of all I've got to say it's smart that the WZ-10 appears to be going with a gun. Some Tiger variants don't even have one.

Henry Yeh did a good job of exploring the likely contenders:

Single barrel 23mm, based on Q-5's NR-23.
Twin-barrel 23mm, based on J-8 & J-10's GSh-23, sorta like Mi-24M.
Single barrel 30mm, based on Su-27's GSh-301, same cartridge as Mi-28.
3 barrel 14.5mm Gatling.
30x113mm M230 clone. PLA isn't well known for logistic common sense.



From the above list let's examine the possibilities:

GSh-301/2A42: The Mi-28's cannon is an airborne vesion of the 2A42 gun used on the BMP-2. While I like the fast flat trajectory I think there is too much lost in off-axis limitations resulting from the high recoil. If we assume that structurally the aircraft will be more like the A129 (cannon on nose) than the Mi-28 (cannon slung near center of gravity) I see a low probability of the 2A42 (or anything high recoil) being used.

M230 Clone: I think this is the best choice, but I'm biased. Seriously though there's still too much recoil here for the A129 layout. Not sure where the plans or a sample would be obtained from to reverse engineer, but then again the US gave the plans for the M242 25mm Bushmaster in the 80's... dunno.gif

Gsh-23: This is what I always expected the WZ-10 to have much like the Mi-35 Hind. Low recoil and high rate of fire.

NR-23: Good news is these have been built in PRC since J-6. Like the Gsh-23 this gun uses the low velocity 23x115mm round.

3-Barrel 14.5mm Gatling: Maybe. This gun is certainly developed for use in aircraft and doesn't seem to have any other fielded applications yet. But this thing is still just throwing slugs unless new explosive ammo is developed for it. This would be better hanging off the back ramp of a Z-8F in a flexible mount than in a powered turret. I think this would be a poor choice for the WZ-10, but it might represent an attempt to emulate the 20mm gatling on the A129 using a locally produced cartridge. Personally I'm sold on cannon for attack helos instead of machineguns, even gatlings. Maybe this has been developed for the WZ-9 program.

Here's some options Henry didn't mention:

GIAT M621 20mm: This is used on the new Puma upgrades in a nose turret. Right size, wrong cartridge for logistics.

GIAT M781 30mm: This is the Tiger's gun and would be the best choice in terms of capabilities and airframe integration, but as I explained in a previous post I don't think the EU had the guts to give this gun to the PRC during their embargo.

Norinco 23mm Chaingun: I think this is going to be our winner because:

1. Unlike all the above options we have already seen it in China in a powered helo turret.

2. The gun is already used on the Z-9G in a fixed mount.

3. Uses 23x115mm ammo produced in PRC and already in Army Aviation supply chain.

4. Meets the recoil/size requirements for placement in a nose turret.

5. It's unarguably an indigenous design. This is important for Agusta and Eurocopter to have plausible deniability of arms embargo violation.

Do you guys think they'll wait until 2006 Zhuhai to roll the WZ-10 out?...I hope not.








Minor correction here: M791 is not used on any helo turret. M781 is 30x113mm, the 20mm gun would be M621.
PLA already has 3 different 30mm series ammos (30x156B, 165, & 173mm) in service, no need to further complicate the already fucked-up logistic with 30x113mm. M230 & GIAT M781 should go out of the window right away. I sarcastically mentioned M230 precisely to chide PLA's practice of "collecting" calibers.
I forgot to mention 25x218mm guns used on PLA AAA. Would these suffer from the same size/recoild limitations as 30x165mm weapons?
I wonder why PLA decided fighter armaments (NR-23 & GSh-23) are unsuitable for choppers. Lack of durability for prolonged suppressive fire? Wastefull of ammo due to high rate of fire?
14.5mm MG fires API rounds that can incinerate a truck from the inside out. HEI are also available though not very popular.









Minor correction here: M791 is not used on any helo turret. M781 is 30x113mm, the 20mm gun would be M621.

smilie_tischkante.gif Duh..my bad. Thanks.


I forgot to mention 25x218mm guns used on PLA AAA. Would these suffer from the same size/recoild limitations as 30x165mm weapons?



That round is pretty hot for a helo turret, and oh so heavy. Maybe in a pod.


I wonder why PLA decided fighter armaments (NR-23 & GSh-23) are unsuitable for choppers. Lack of durability for prolonged suppressive fire? Wastefull of ammo due to high rate of fire?



Really I can't explain it. If the GSh-23 is good enough for export Hinds it should be good enough for the WZ-10. Maybe it's too heavy for the WZ-10 turret or not as reliable. The Norinco chaingun is probably preferable to the NR-23 because it's likely lighter and more reliable. If a chaingun misfires it just keeps going.


14.5mm MG fires API rounds that can incinerate a truck from the inside out. HEI are also available though not very popular.



If Norinco debuts a new line of 14.5mm HEI in the near future I'd say that would be a pretty good indicator. Actually the more I think about it the 14.5mm API might pack a pretty good punch too. Here's the force equations worked out to put these guns in perspective:

MVV Calculations
14.5x114mm API weighing 64 grams at 1000m/s out of a KPV: 64,000N
23x115mm API weighing 200 grams at 610m/s out of a NR-23: 74,420N
20x102mm weighing 101 grams at 1030m/s out of an M61: 107,150N
30x113mm APHEI weighing 275 grams at 775m/s out of M230: 165,171N
25x218mm AP-T weighing 281 grams at 900m/s out of a Type 61: 227,610N
30x165mm AP-T weighing 400 grams at 880m/s out of a 2A42: 309,760N

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