Author Topic: Mk 108 30mm (Read 5509 times)

EagleDNY · « **Reply #45 on:** December 18, 2006, 08:50:47 AM »

Quote

Originally posted by Benny Moore
Ever shot a gun? Smaller often means denser. I've shot hollow objects with hollowpoints, and I've also shot smaller solid objects with the same. Hollow objects get torn apart, solid objects just get small holes.

If your hollowpoint was filled with explosives and detonated on impact I'd say you could try this comparison, but having shot a quite a few rounds off myself I can say definitely that bullets and cannon rounds are different animals entirely.

A hollow point striking a hollow target and fragmenting / ripping it apart is still simple kinetic energy, even if split into multiple fragments which travel completely through the target. A hollow point hitting a solid target which absorbs the fragments after the initial penetration is still suffering from the kinetic energy, and the fact that the fragments don't come out the other side doesn't mean that any less damage was caused.

A solid target (like a man), hit by a 9mm gets a 9mm hole drilled through him. Hit by a 9mm hollow point which fragments, that solid target gets the fragments ripping through which tends to cause much actual damage. Same 9mm hole, different results.

A cannon round is completely different - besides the initial kinetic energy, you get the high explosive detonation after impact. This gives you some lovely fragmentation, and more importantly a nice explosion with all the added energy of the blast effects / overpressure. The picture up the thread of the 30mm exploded while suspended in the fuselage gives you an idea of how much energy just the EXPLOSION releases.

Couple that explosion with the actual kinetic energy of the round, plus realize that the target and the round are both MOVING when the detonation occurs, and you get an even bigger mess. I don't know that HTCs damage model can be accurate on the directional effects, but the overall effect of a 30mm hit on aircraft seems OK to me when I'm in my 109K4.

Can a fighter survive a Mk-108 30mm hit - maybe, they aren't designed to penetrate armor, so if it hit an armor plate maybe you could take one if the blast didn't blow off anything vital. Set one off in the wing of a P51 near that wing tank, and I'd say your toast. It all depends on the situation.

EagleDNY
$.02

Keiler · « **Reply #46 on:** December 18, 2006, 02:03:30 PM »

Watch this:

http://www.youtube.com/watch?v=Oc9E8_ZuESQ

Then there was a video where some guys fired a 30cal, 50 cal and 20mm AP and HE on a wing dummy made of sheet alu, but I cannot find it to save my life.

Anyone has a link?

Pretty impressive when you compare 20mm HE with 50cal ball.
I have the said vid on my HD, but no upload space. Any directions to do this?

Matt

Bronk · « **Reply #47 on:** December 18, 2006, 02:18:57 PM »

Quote

Originally posted by Benny Moore
Ever shot a gun? Smaller often means denser. I've shot hollow objects with hollowpoints, and I've also shot smaller solid objects with the same. Hollow objects get torn apart, solid objects just get small holes.

Ever blow stuff up?

Try putting an M-80 in a ... mailbox. (I do not endorse doing it but have seen first hand what it does.)

Blows the hinged lid off. Often times blossoming the end or even blowing it off the post.

Now take that same M-80 and drop it in a 33 gal trash can .

While it will blow the lid off it will hardly distort the shape of the can.

Bronk

Reynolds · « **Reply #48 on:** December 19, 2006, 06:33:23 PM »

Quote

Originally posted by EagleDNY
Can a fighter survive a Mk-108 30mm hit - maybe, they aren't designed to penetrate armor, so if it hit an armor plate maybe you could take one if the blast didn't blow off anything vital. Set one off in the wing of a P51 near that wing tank, and I'd say your toast. It all depends on the situation.

EagleDNY
$.02

In ALL of the time I have fired 30mm I have never seen ANY plane smaller than a B-24 survive the impact of even ONE 30mm. From all I have seen, one shot + one hit = one kill. Even P-47s fall apart. This is a BIG round, with a BIG boom. Its kinda like smashing a hole open with a baseball bat and tossing a grenade inside. It goes BOOM in a big way. I dont know who this Tony Williams guy is, I have never heard of him, but I have yet to see a single word typed by him that didnt sound like it came from the maker of the shell himself. He knows his guns. There is virtually NO way a fighter takes less damage from a 30mm. The ONLY situation in which I can fathom a fighter taking less damage is on a fabric plane where the shell doesnt decelerate from the impact enough to detonate and goes out the other end. Anything with stressed metal, aluminum, and probably wood is TOAST. Even Mosquitoes fall apart when I shoot them. The 30mm is teh ub3r 1337 when it comes to guns!

Debonair · « **Reply #49 on:** December 19, 2006, 07:09:53 PM »

anyone have a copy of the photo of a P-51 that took an Mk108 hit in the vertical stabiliser?

Charge · « **Reply #50 on:** December 20, 2006, 05:01:03 AM »

"anyone have a copy of the photo of a P-51 that took an Mk108 hit in the vertical stabiliser?"

Probably not. I bet there is not much left to take pictures of.

-C+

Hazzer · « **Reply #51 on:** December 20, 2006, 05:20:47 AM »

The mk 108 is not that heavy compared to the mk 103, coming in at less than half the wieght.One round took the tail clean off a f4u1a last night.

EagleDNY · « **Reply #52 on:** December 20, 2006, 05:42:40 AM »

Quote

Originally posted by Reynolds
In ALL of the time I have fired 30mm I have never seen ANY plane smaller than a B-24 survive the impact of even ONE 30mm. From all I have seen, one shot + one hit = one kill. Even P-47s fall apart. This is a BIG round, with a BIG boom. Its kinda like smashing a hole open with a baseball bat and tossing a grenade inside. It goes BOOM in a big way. I dont know who this Tony Williams guy is, I have never heard of him, but I have yet to see a single word typed by him that didnt sound like it came from the maker of the shell himself. He knows his guns. There is virtually NO way a fighter takes less damage from a 30mm. The ONLY situation in which I can fathom a fighter taking less damage is on a fabric plane where the shell doesnt decelerate from the impact enough to detonate and goes out the other end. Anything with stressed metal, aluminum, and probably wood is TOAST. Even Mosquitoes fall apart when I shoot them. The 30mm is teh ub3r 1337 when it comes to guns!

I've flown 109K4s, come in on a bomber seen multiple hits and the bomber (B17) survive the pass. Was that MG fire and not multiple cannon hits? Who knows, but the bomber kept on going.

Fighters that get hit with a 30mm round in AH are basically toast, and rightly so. I've gotten single hits on P47s and it brought them down, and the P47 is probably the toughest fighter in the game. I've also gotten hits on fighters that I would've swore was a cannon hit and they survived.

IRL I do remember reading an account of a Jug pilot who took a cannon shell to the engine which actually blew cylinders off, yet he was able to get his plane home. It is pretty amazing sometimes to see pictures of planes that took severe hits yet still made it back to base - wingtips, engines, stabilizers shot completely off and still flying.

I agree that a 30mm hit is devastating, but I do hesitate to say that it is 100% instantly fatal to a fighter. That said, I sure don't want to be on the receiving end

EagleDNY
$.02

Trikky · « **Reply #53 on:** December 20, 2006, 08:36:03 AM »

I've had two surprising experiences against Ki61's, one with a LW 30mm and the other with a VVS 37mm where they took the hit as they crossed vertically across my sights, so nigh on perpendicular, in roughly the same place - just inboard of the aileron, and they've carried on flying with no visible damage.

I've also blown my own arse off, given myself pilot wounds, oil and radiator leaks, broken my guns, by shooting too close with said weapons.

edit. Eagle I think I've read something similar about a P47 losing huge chunks of engine yet still the pilot had the confidence to do some light strafing of railroads and ships, on his way back to base. Pretty amazing.

Apeking · « **Reply #54 on:** December 20, 2006, 04:47:30 PM »

"I have yet to see a single word typed by him that didnt sound like it came from the maker of the shell himself"

Emmanuel Gustin, the co-writer of the quoted book, gives a thorough overview of historical aircraft armament here. I am sure that this has been posted many times before. But not by me. Him, Tony Williams, Greg Goebel, and Mark Prindle are the only people I trust on the internet. And also the Russian chap, you know. Maxim Popenker. And also Greg Starostin. NB My interests run to more than just guns, planes, and the Ramones.

There are some charts of weapon performance on Emmanuel's site. They strongly suggest that the ultimate aircraft gun is the Russian GSh-6-23, a six-barrel rotary cannon fitted in the Mig 31. It weighs about the same as me, and fires at 8-10,000rpm. A single GSh-6-23 has over twice the weight of fire as four 30mm Mk108s, and is one of the hardest cannons to type. I have no idea why the Russians put a cannon in the Mig 31. I can understand why this particular cannon might have been fitted into a Mig 31. But for what purpose?

There is also a chronological list of fighter armaments, which reveals that the Me262's 4x30mm weight of fire - which is of course just one attribute - was roughly equivalent to twenty-two yankee 12.7mms. I did not know that the Bf109K6 existed and could be fitted with 3x30mm. I bet it's on someone's wishlist.

I find it hard to write about Emmanuel Gustin's website without thinking of a naked Sylvia Kristel swimming in a pool. But is that such a bad thing?

Tony Williams · « **Reply #55 on:** December 20, 2006, 11:46:54 PM »

The GSh-6-23 was fitted to the MiG-31 primarily to deal with easy or low-value targets not worth one of its big AAMs, such as cruise missiles (and nowadays UAVs, no doubt).

However, the gun (which is also fitted to the Su-24) has run into problems with premature shell detonations causing damage to the aircraft, so these days they don't use them (the planes keep the gun, but it's never loaded).

As a matter of interest, my specialities are ammunition and guns, Emmanual's aircraft and gun installations. I helped him with his website initially, then we decided to co-operate on the Flying Guns series. You will find various other articles on aircraft guns (ancient and modern) on my website.

Tony Williams: Military gun and ammunition website and discussion forum

Keiler · « **Reply #56 on:** February 20, 2007, 01:32:16 AM »

Quote

Originally posted by Keiler
snip

Then there was a video where some guys fired a 30cal, 50 cal and 20mm AP and HE on a wing dummy made of sheet alu, but I cannot find it to save my life.

Anyone has a link?

Pretty impressive when you compare 20mm HE with 50cal ball.
I have the said vid on my HD, but no upload space. Any directions to do this?

Matt

Found it:

http://video.google.de/videoplay?docid=-9101895862044064019&q=20mm

Testfire with different calibres on a wingdummy.
Enjoy!

Matt