120mm Zaku Machine Gun VS Luna Titanium Alloy & GM Shield

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Gelgoog Jager
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120mm Zaku Machine Gun VS Luna Titanium Alloy & GM Shield

Post by Gelgoog Jager » Thu Aug 13, 2015 12:03 am

Currently I'm catching up with the The Origin manga (just finished volume 4), right after the failed assault on Jaburo and I was reminded of how the 120mm Zaku machinegun, AKA as Hyper Rifle in the manga, is also shown to be consistently ineffective against Luna Titanium Alloy as well as against the generic shields used by the GMs.

One of the reasons I'm interested in such discussion is the fact that in a previous thread about Zaku machine guns there was mention of a particular model of Zaku machine gun which uses shorter bullets which are meant to be used against soft targets (vehicles and infantry):

http://www.mechatalk.net/viewtopic.php?f=17&t=15769

The weapon in question is the M120A1, which originally was the model used by all the Zaku II appearing in the original series. In turn, originally all the 120mm MG from 0083 were MMP-78 and the ones from 08th MS Team were ZMP-50D. However, supposedly retcons now say stuff such as there being a middle period MMP-78, which looks identical to the M120A1, and which was used by Zakus from the First Gundam.

Leaving that aside for a moment, the fact that the M120A1 is using shorter bullets is also reflected on the ammo drum, which stores the bullets vertically instead of horizontally, and can supposedly carry 332 rounds instead of the 100 rounds that the other models use and which are stored horizontally in the ammo drums:

http://smg.photobucket.com/user/YFX-600 ... 0.jpg.html

My point is that the explanation about the M120A1 makes it sound like that particular model is the one that has no effect on Luna Titanium Alloy. The MMP-78 on the other hand is is supposed to have been improved for anti-MS combat. The ZMP-50D is said to be the ground use version of the ZMP-50, which itself was a space weapon with low muzzle velocity and whose AP rounds were said not to be very effective. Ultimately we could say that in terms of effectiveness against MS:

M120A1 < ZMP-50D < MMP-78

Now, my main concern is regarding the effectiveness of the ZMP-50D and the MMP-78 against Luna Titanium Alloy and the EF's OYW MS shields. First some quick notes on these:

LTA: as observed in 08th MS team, the armor on different sections of the MS can have quite different resistance, with the Gundam[G]s getting only a a large dent from a Magella Gun shot to the chest, but having their leg armor completely blown off by an attack of the same weapon.

I would like to mention that for a while I thought that the main reason Zeon began using Magella guns was to give Zakus weapons that could damage LTA given the commonly mention ineffectiveness of 120mm machine guns.

Gundam/GM shields: even if we only focus on the basic red rectangular shields, it's hard to asses them since we have some radically different examples of their durability: in the 0081 OVA, the Gundam can easily deflect Zaku bullets with its shield, but in Gundam Frag 1 we see how an unidentified MS fires a few machine gun rounds at a RGM-79 and these pierce its shield, with one round reaching all the way into the cockpit.

Perhaps we could assume that the one from 0081 is a M120A1, while the one from ZZ Frag is a MMP-78?

Taking these instances into account, I would like to think that the ZMP-50D and specially the MMP-78 are far more effective against EF units than the M120A1 from the First Gundam. The MMP-78 in particular may even be able to pierce GM shields and perhaps even damage Luna Titanium Alloy, at least on lightly armored areas such as on the armor covering the limbs.

But what does everyone else thinks of this situation?

Should all 120mm Machine Guns be useless against LTA and Gundam/GM shields? If not, how effective should the different 120mm machine guns be?

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Re: 120mm Zaku Machine Gun VS Luna Titanium Alloy & GM Shiel

Post by Wingnut » Thu Aug 13, 2015 12:36 am

As before, it is possible that it all comes down to not the gun that fires the round, but the round itself. The later ammo shown used by the MMP-78 resembles a rifle round while the M120A1 is much like a pistol round. Like a 30.06 from a M1 Garand vs. a .45ACP from a Thomson, one is far better at getting through armor than the other.

Also for some reason, I can't recall a MMP-78 actually hitting anything in 0083. It's been awhile since I watched it last., but I don't remember it happening. Most MS kills by Zeon projectile weapons seemed to come from the MMP-80.
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Re: 120mm Zaku Machine Gun VS Luna Titanium Alloy & GM Shiel

Post by Brave Fencer Kirby » Thu Aug 13, 2015 2:32 am

How common was luna titanium during the One Year War? My impression was that it was pretty much exclusive to Gundam-type mobile suits, which were relatively rare during the war -- certainly it doesn't seem worth changing the primary weapon of the entire Zeon mobile suit compliment just to deal with a handful of wandering troublemakers like the White Base and a few isolated units like the Kojima Battalion.

Of course, I was also never certain whether the Gundam's shield was supposed to be made of luna titanium or not. On the one hand, it would seem odd to use a shield that's less durable than your regular armor -- but on the other, luna titanium is supposed to be rare and expensive, and Amuro goes through an awful lot of shields over the course of the show without any mention of them being difficult to repair or replace. And even if the Gundam's shield was luna titanium, that doesn't necessarily mean that the GM's was, identical-looking or not.

That said, in regards to the original question, the effectiveness of ballistics vs armor is a lot more complicated than it may seem at first glance. First off: are these weapons firing explosive warheads, like most shells of their caliber in real life are? Or are they simply firing solid bullets, like a scaled-up infantry weapon? If they're explosive, are they generic multi-purpose HE shells, or are they dedicated anti-armor HEAT rounds? If they're kinetic, are they full metal jackets, hollow points, or long-rod penetrators? Even if we knew all that, their exact performance is going to depend on the range to target, the angle it impacts against armor, and the quality of both the weapon and the round being fired (how long has it been since they've done maintenance on the gun? Is the ammo fresh from the factory, or has it been exposed to the elements after being strapped to a Zaku for a few weeks? Did Zeon's manufacturing standards slip during the final months of the war, so the ammo isn't as powerful as it should be?), etc etc etc.

Really, there's enough wiggle room in there to justify basically any performance you want, even before you start positing things like guns with vastly different performance despite identical appearances.
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Re: 120mm Zaku Machine Gun VS Luna Titanium Alloy & GM Shiel

Post by Gelgoog Jager » Thu Aug 13, 2015 3:22 am

@Wingnut: That's a good comparison.

A detail I forgot to mention is that there's actually some logic in the evolution of round size between these weapons:

ZMP-50 (long round): a weapon intended for use in space at the beginning of the war, most likely with warships as its intended target, given that space fighters seem rather scarce.

M120A1 (short round): a weapon intended for use on Earth. Since land battleships seem to be rather few in number, but on the other hand the EF ground and air forces consist on numerous smaller vehicles, it makes sense that a weapon with higher ammo capacity for dealing with many minor threats was picked.

MMP-78 (long round): a weapon intended for use against MS. When it became evident that the M120A1 was rather ineffective against EF MS, this weapon was probably pushed as a countermeasure, most likely along the MMP-80 which seems serves a similar role, though with greater focus at close range situations.

The big question is if the long round was brought back for the MMP-78 because information or tests did indicate that it was more effective against MS, or simply because it was the fastest way to quickly push a more effective weapon against MS after the inefectiveness of the M120A1's shorter rounds became an issue of concern.

As an extra note, the fact that the Dom's machine gun with the larger grip is a MMP-78 model somewhat confirms that despite not continuing with the Gouf's anti-MS melee capabilities, Zeon did expect the Dom to run into EF MS and gave it a machine gun for dealing with them, rather than a ground use M120A1 for dealing with other soft targets.

@Brave Fencer Kirby: Well, for starters the RX-77-2 Guncannons from the First Gundam are supposed to also use LTA (and definitely seem to be more heavilya rmored than a Gundam) and are supposed to be somewhat common early on, specially before the GMs start rolling out in large numbers.

Second, we have the RGM-79[G]s and RX-79[G]s, which are rolled out almost at the same time. It's quite likely that during the first encounters, if short M120A1 proved ineffective against RX-79[G]s, Zeon thought that the same mgiht be the case with the similar looking RGM-79[G]s.

Last, but not least, over the years more games, mangas and stories have added more and more Gundam units, specially RX-79[G]s and variants (Wraith Slave for example).

It's hard to say what material about the Gundam/GM shield is amde off. However, quite recently Mark posted this:

First Gundam: The Sunrise list calls the Gundam's shield "Gundam shield" (and lists it for the GM as well)

viewtopic.php?f=17&t=15951&start=380#p376640

If the Gundam and GM indeed use the same shield it would seem likely that they would use soemthign less expensive than LTA. But on the other hand, it would make little sense for the Gundam to use a shield of a less durable material than its own armor. Perhaps it was only intended to block explosives?

You make some valid points about other factors that can affect the effectivness of the rounds. However, let's stick to the cases we know:

-The battle at Side 7: in space the rounds shouldn't face as much deterioration, if at all. The same probably applies to the ammo of most space bound forces.
-The battles in North America: since most MS seemed to belong to units under Garma's command from the EAF's HQ, I would like to think their ammo was in good condition.
-Ramba Ral's forces: now this is probably the most likely bunch to have gotten ammunition in poor condition, specially with M'quve's active sabotage of their supplies.
-Minor bases along Asia and Europe: other likely candidates for ammo in subpar condition, specially if they are in the middle of nowhere.
-Odessa defense forces: we are back to forces that should technically have access to ammo in good condition, at least before and during the battle of Odessa itself.
-Jaburo attack forces: If they came from California Base, they should also have good stuff.
-Space battles before the end of the war: I suppose it's possible that the worsening situation could have affected the quality of the supplies available, but still these shouldn't be as noticeable in the case of the forces defending large bases.

So, at least as far as First Gundam is concerned, in most cases the Zakus should have had access to ammo in good condition, except for some cases on Earth.

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Re: 120mm Zaku Machine Gun VS Luna Titanium Alloy & GM Shiel

Post by Xenosynth » Thu Aug 13, 2015 4:45 am

I know it's technically not official, but I was curious if maybe the perfect file's section on the Gundam shield might have any new info? I can't translate it myself but here is the bit.

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Re: 120mm Zaku Machine Gun VS Luna Titanium Alloy & GM Shiel

Post by Massignifico » Thu Aug 13, 2015 6:25 am

A bit unrelated but the inconsistency it's present in the Hizack's Zaku Machine Gun Kai too. When Jerid fires at the capsules that contains Kamille's parents the ammo couldn't damage the MkII's fingers (weak spots armored with old titanium). Later, during the night battle at Hong Kong, a passing Hizack destroys the right arm of Amuro's Rick Dias (a place surely tougher, even armored with Gundarium gamma). Maybe in the first case Jerid was using softer ammo?

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Re: 120mm Zaku Machine Gun VS Luna Titanium Alloy & GM Shiel

Post by Gelgoog Jager » Fri Aug 14, 2015 2:08 pm

Well, we do have a clear example of a Zaku machine gun using two different types of ammo: the MMP-78, which can alternatively use a smaller clip which supposedly carries AA ammo:

http://oi40.tinypic.com/2cdidrd.jpg

In said example, while the two different sets of round are stored in a different type of catridge/drum each, they use same opening for the feeding mechanism. I suppose it could be possible for the Hizack's weapon to use different types of ammo as well. Besides there are already mentions of Zaku machine guns using different types of ammo.

As piece of trivia, the Act Zaku from the Zeonography series includes both the Zaku beam rifle and 120mm machine gun used by the Hizack. While in Zeta Gundam we indeed see some Act Zakus using this beam rifle, the MS-11 has been depicted with the MS-11 during the OYW in some video games and mangas, leading to the presumption that the beam rifle originally belonged to the Act Zaku and was later mass produced for the Hizacks. It's possible that the Zeonography set intended to indicate that the 120mm Zaku machine gun kai is also a weapon orignally belonging to the Act Zaku and later passed down to the Hizack.

Besides, we already have examples of mass produced EF MS using Zeon weapons: the RMS-117 Galbaldy Beta (uses the same beam rifle from the MS-17 Galbaldy Alpha) and the RM-192M Zaku Mariner (uses the subroc gun from the MS-06M/MSM-01).

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Re: 120mm Zaku Machine Gun VS Luna Titanium Alloy & GM Shiel

Post by Wingnut » Sat Aug 15, 2015 12:07 am

Can you use something other than ZOINKS tinypic to host that image? That site is infected with mountains of ads and I can rarely if ever see the actual intended image. Imgur is the best IMO for quick and dirty image hosting.
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Re: 120mm Zaku Machine Gun VS Luna Titanium Alloy & GM Shiel

Post by Gelgoog Jager » Sat Aug 15, 2015 1:09 am

Wingnut wrote:Can you use something other than ZOINKS tinypic to host that image? That site is infected with mountains of ads and I can rarely if ever see the actual intended image. Imgur is the best IMO for quick and dirty image hosting.
I found a better pic and replaced the host. Hope that helps.

By the way, I just noticed we have a few other weapons that are using 120mm rounds:

-Gatling gun from the MS-06JK and MS-06K
-Gatling gun from the MS-07G-2
-Drum-fed machine gun from the RMS-141

Also, as discussed on another thread, it would seem that the Gouf's Custom gatling gun might actually be using the same caliber round as the 120mm machine gun:

http://www.mechatalk.net/viewtopic.php?f=17&t=15768

Perhaps in the end all these weapons actually use the same rounds?

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Re: 120mm Zaku Machine Gun VS Luna Titanium Alloy & GM Shiel

Post by MythSearcher » Sat Aug 15, 2015 3:57 am

RX-78-2 and RGM-79 use the same shield, and from PG manual, the shield has a layer of Lunar Titanium in it.
The problem is the thickness of said layer, and the quick fixes mechanics make on field.

Depending on the quality control of the EFF, I assume it will be like real life and be separated into a range of grades, some will get a thinner layer of LT, some get a thinner layer of other material(actually multiple other layers, you get my point), some get both thinner and some get both thicker. The thicker ones get a higher grading and likely given to more battle intense area(and likely to Gundams) while the thinner ones given to less prominant units.(Of course some do not pass the par and gets scraped, some may be simply too thick and too heavy and get the same disposal process) The difference of the thickness may get up to 10~20% for the highest grade and the lowest grade.

The shield is able to take a round or two, but in a real life situation, that does not mean it has no damage. The impact force, heat and vibration damages the layers, the round might not have penetrated, but the damage is there. Now, even for EFF, they are not likely to have infinite resources in every bases, have like 50 shields for every MS, and likely cannot change shields everytime they were hit by a round or two, or simply your next shipment of supplies has not arrive yet, or it cannot arrive due to enemy fire, etc.
So what do you do?
If you have time and the machines you maybe able to take the layers apart and fix every layer one by one, but that is not very likely given a tight schedule in the frontlines, the mechanics have to repair the MSs as well.(You have all those armour and internal structure to fix)
Fix the area by filling the dent with repair materials, weld a new layer of metal down and sand it down before reapplying the paint, etc. These gets the shield LOOK new and shiny, but of course the structure integrity lowers. The enemy will not know this, and not likely to abuse the weak point in an intense battle situation when everything is moving, so it should not be a big problem doing that. Scraping the shield may take even more time, since you don't want your enemy picking it up and using them for improvised armour, so you have to destroy them to a certain point, or burying them deep down, etc.
These are the ones that are likely to be penetrated after repeated fixes, it is quite hard to keep count of the fixes and without equipment, had to check them without damaging them. You can make a mark on it for the sake of keeping check, but that is more likely prone to damage if it is small(even by a scratch from the MS), and a big sign defeats the purpose(and the enemy is more likely to be able to interpret the meaning)

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Re: 120mm Zaku Machine Gun VS Luna Titanium Alloy & GM Shiel

Post by nickh46 » Sat Aug 15, 2015 5:00 pm

Is it still 120mm? In volume 1 of the Origin when the Zakus attack Side 7, there's shell casings from their rifles that say "Zeon Arms 140mm" on 'em.

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Re: 120mm Zaku Machine Gun VS Luna Titanium Alloy & GM Shiel

Post by Xenosynth » Sat Aug 15, 2015 11:35 pm

The Origin versions of many suits are a bit different from the animated show and other showings, such as how the Zaku IIs also have chest and wrist vulcans, the cannon attachment for the Gundam, the RX-78-01 depicted being completely different from the original RX-78-1, etc.

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Re: 120mm Zaku Machine Gun VS Luna Titanium Alloy & GM Shiel

Post by Gelgoog Jager » Fri Aug 21, 2015 4:19 pm

I should also point out thta while the 140mm Hyper Rifle from The Origin manga is belt-fed from a drum installed beneath the backpack, the animated version uses the standard ammo drum of the common 120mm Zaku machine gun. Perhaps the 140mm machine gun is being replaced in the OVAs by a common 120mm hyper rifle.

Actually, I had mentioned this on another thread, but there's a weapon in a similar situation: The machine gun of the Xeku Eins. This weapon resembles a MMP-80 series 90mm submachine guns, but uses a larger caliber than the other MMP-80 (it is said to be 120mm) and incidentally is also belt-fed from an ammo drum installed on the MS itself. Could there be a connection here?

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