YaATW2KT: The Second Mexican-American War

[RN7]

Originally Posted by Olefin

obviously the AMX-13 would fit in with the real life Mexican Army - i.e. the AMX-VCI that they did end up buying is the infantry carrier variant of the AMX-13 tank - so that plays right into the same general tonnage

I have little problem with Mexico using the AMX VCI in this period, but I don't think it's possible that they got them from Belgium due to the on going Cold War in Europe. France would be a much better source.

As part of the Paleme-4/6/7 deals France delivered 120 ERC-90, 48 VCR-TT, 40 VBL including 8 with Milan anti-tank missiles, 32 MO-120 RT 120mm mortars and 80 MILAN anti-tank missiles to Mexico in the 1980's. I see no reason why this arms trade would not continue into the 1990's, as we know that France delivered 4 AS-555 Fennec armed helicopters in 1993.

At this time France was in the process of upgrading its land forces with new equipment such as the LeClerc tanks, AMX-10RC, AMX-10P, VAB, GCT SF artillery and towed field artillery, anti-tank and air defence missiles etc. GDW also lists the AMX-40 tank. A whole generation of French military equipment was becoming obsolete in French usage in the later stage of the Cold War, including the AMX-30 tank, AMX-13, AMX-VCI, F3 SP artillery etc. France has a greater arms manufacturing capability than Belgium, and it could produce new vehicles far quicker than Belgium making it plausible that older vehicles could be replaced and become surplus. France and Mexico could agree to another Paleme deal in the 1990's to transfer second hand military vehicles and some new arms to Mexico.

The Mexican Army Sourcebook basically implies that this happened. I don't believe that the numbers listed in the Mexican Army Sourcebook that include hundreds of AMX-30 tanks would be possible, due mainly to the fact that Mexican forces and defence spending could not accommodate or afford these numbers. It would also lead to even bigger problems with the Americans who would not be happy with Mexico massively increasing its armed forces and capabilities south of the border, and would probably lead to major American political and trade problems with France and Mexico. However reduce those figures to dozens rather than hundreds and it would be less noticeable and more manageable. A few dozen AMX-30's, more AMX-13 and AMX-VCI and some F3 and towed artillery, along with some new French anti-tank missiles and SAM's etc and a dozen helicopters would not alarm the Americans that much as it would still be very modest in comparison to the numbers that U.S. forces have pre-war. It would also explain how Mexican forces were able to invade and hold American territory.

[Olefin]

I agree with RN7 on the AMX-13 - for one the Mexicans in real life bought the AMX-VCI which is the APC version. And its light enough that it would be something that would actually work with Mexico's pre-war needs - i.e. they werent looking to take on the US - so they werent thinking M1A1 they were thinking more like what do we need to take on rebels and possibly Guatemala or Honduras

The AMX-13 has got a good punch for a light tank as well. And I also agree with RN7 on the probable fact that the French wont be looking to sell them hundreds of anything - looking at the composition of the Mexican Army even a battalion worth of AMX-13 tanks and a battalion or two of AMX-VCI APC's gives them better combat power than before and its line with the size of previous French sales to Mexico.

Given the inherent weakness of American forces left in the US by the time of the invasion they may have been able to pull it off without even MBT's - even light tanks and armored cars may have been enough. And they did bring in Soviet Division Cuba for the muscle when they did need it to stop the charge of the 49th.

If you want to stay in line with canon then there should be at least a couple of battalions of the VAB as well if not more - Red Star Lone Star has that as the primary Mexican APC.

They are the canon APC - but the question is how many did they have - i.e. sure they had them in Texas - but that doesnt mean they had a lot of them. (and the ones I am thinking about would be the basic version equipped with either a machine gun or the 20mm cannon and most likely ones that are already 15 or so years old - i.e. from the original deliveries and about ready to be refitted)

[dragoon500ly]

Interesting, by the early 1980s, most of the French AMX-13 tank production was the 90mm and 105mm variants with many mounting quad SS-11 ATGMs.

Not only were there APCs but also self propelled howitzer and guns, and ADA variants.

One can almost see a Mexican Army purchase of 1-2 brigades worth from the French. Keeping the initial purchase at this level would give the Mexican Army a nice modifier against the light infantry/MP units that were fielded during the invasion as well as a useful force against what ever tanks the US could died in response.

[Olefin]

If you look at the biggest armored vehicle buy the Mexicans had (in reality not the canon) it was the buy of approximately 500 vehicles (all APC's) from Belgium in 1994-1996 - given that you can assume that is about how many they would have been looking for in the canon timing as well with most of the buy leaning towards APC's

however some kind of light tank is a definite possibility as part of this mix for the canon versus the real life buy

again it comes down to Mexican behavior in the canon versus real life

if real life Mexico never saw the US as a serious enemy they had to arm themselves against and thus never looked at tanks as a need for their army

in the canon this changed - but the question is when did it change? After the nuclear strikes on Mexico - in that case its too late to really arm themselves with new weapons like heavy tanks - or did it change years earlier - and the canon in many ways doesnt really address that.

Again the nature of the US forces that were in the border areas (keep in mind the 49th was deployed on peace keeping duties a long way from their native Texas when the invasion occurred) tends to suggest to me that this transformation in attitude happened after the nuclear strikes as the civil situation in the US and Mexico deteriorated and the Mexican government needed some way to rally their people around the flag. In other words the first inkling the US had of the invasion was seeing those Mexican APC's crossing the Rio Grande and striking over the border from Tijuana.

You would think if they had added a lot of heavy tanks to their arsenal the US would have been paying a lot more attention to that border at the least for the potential threat. Especially considering the only real country to buy those tanks to use against was us. Now a small number could be possible - ie.. they could be seen as an offset to the Nicaraguan Army which did have tanks (old T-54/55 and PT-76 light tanks). I could easily see Mexico telling a nervous US general in 1993 that the AMX-13 tanks they are getting are to take out the Nicaraguans if they ever come across the border - and thus they are never figured into US strategic decisions until they encounter them in Texas or CA

[RN7]

The main problem with Mexican versus US forces in the Twilight War is that U.S. forces have a whole load of weapons that can defeat all Mexican armour, but the Mexicans have none that can defeat the M1 Abrams tank.

The ERC-90 and AMX-13 armed with a 90mm gun can defeat lighter U.S. vehicles and older tanks, but not modern tanks. An AMX-13 armed with a 105mm gun can defeat the M48 and M60 tanks, but only if it is using HEAT or APFSDS rounds. It cannot defeat any variant of the M1 Abrams tank or an M60A3 with reactive armour. The ERC-90 and the AMX-13 are also very lightly armed vehicles and vulnerable to all U.S. tanks and anti-tank weapons. In fact they would also be vulnerable to the Bradley's 25mm canon.

Mexican forces also use the Milan missile. France supplied 80 Milan 1 missiles to Mexico in mid-1980's. The Milan 1 missile can defeat the M48 and M60 tank, but cannot realistically defeat any variant of the M1 Abrams tank or an M60A3 with reactive armour. The Milan is also wired guided and short ranged. The Milan 2 missile is a bit more powerful but the French kept this missile for themselves in this period, and it couldn't penetrate an M1 Abrams either.

[dragoon500ly]

Originally Posted by RN7

The main problem with Mexican versus US forces in the Twilight War is that U.S. forces have a whole load of weapons that can defeat all Mexican armour, but the Mexicans have none that can defeat the M1 Abrams tank.

The ERC-90 and AMX-13 armed with a 90mm gun can defeat lighter U.S. vehicles and older tanks, but not modern tanks. An AMX-13 armed with a 105mm gun can defeat the M48 and M60 tanks, but only if it is using HEAT or APFSDS rounds. It cannot defeat any variant of the M1 Abrams tank or an M60A3 with reactive armour. The ERC-90 and the AMX-13 are also very lightly armed vehicles and vulnerable to all U.S. tanks and anti-tank weapons. In fact they would also be vulnerable to the Bradley's 25mm canon.

Mexican forces also use the Milan missile. France supplied 80 Milan 1 missiles to Mexico in mid-1980's. The Milan 1 missile can defeat the M48 and M60 tank, but cannot realistically defeat any variant of the M1 Abrams tank or an M60A3 with reactive armour. The Milan is also wired guided and short ranged. The Milan 2 missile is a bit more powerful but the French kept this missile for themselves in this period, and it couldn't penetrate an M1 Abrams either.

The actual armor thickness ranges from 40mm to 10mm, flank and rear of the AMX-13 is actually vulnerable to .50 BMG armor piercing and 40mm HVHEDP rounds.

The 75mm version was an adoption of a WWII German gun, it can fire AP, HE, Canister and Smoke. The 90mm is the same lightweight version as mounted of the AML-90 armoured car, it fires HEAT, HE and Canister. This was why the French started mounting SS-11 missiles in an effort to counter T-62 tanks.

Perhaps the greatest weakness of the tank is its autoloader, the two six round drums have to be loaded from the outside of the tank and they must load the same type of ammo, the left drum could be loaded with HEAT and the right drum with HE for example.

The usual tactics involved creeping up on target, firing off as many rounds as possible (the 12 rounds could be fired in about 1.5 minutes) and retiring rapidly back, and getting out of the turret and reloading the drums.

[Olefin]

And that is why they brought Soviet Division Cuba along for the ride - i.e. to have people who had the tanks and the ability to take out M1A1 tanks

also keep in mind that they most likely used the terrain to their advantage when it came time to take on US tanks (i.e. avoided fighting any kind of long or mid-range fight where their guns had zero chance of doing anything) - much like the US did when they took on superior tanks in WWII - and they may have fought M1 tanks using infantry tactics if the US actually sent tanks into the cities or built up areas (i.e. took a page out of the Russian Stalingrad book on fighting tanks)

one reason I am highly doubting, in my opinion, they had MBT's in any numbers at all is the description of two battles in the canon - the one in Texas where a bunch of military cadets held off the Mexican Army for three days and finally had to be beaten by massed artillery - and the stand of the School Brigade at El Paso (which was armed basically with anti-air weapons and not anti-tank) which eventually only retreated because they were about to be enveloped

either of those stands make good sense against light armored vehicles

but MBT's would have made short work of either force (definitely the military cadets and most likely the School Brigade as well)

That makes me lean to either them depending on Soviet Division Cuba (which wasnt in either battle) or a possible small silver bullet force that they would only use after all else failed and after US tanks numbers had been degraded as much as possible beforehand instead of attempting to engage in tank on tank battles first

[Olefin]

FYI has anyone else read Trial By Fire - Harold Coyle's book about a US Mexico war?

[RN7]

Originally Posted by dragoon500ly

The actual armor thickness ranges from 40mm to 10mm, flank and rear of the AMX-13 is actually vulnerable to .50 BMG armor piercing and 40mm HVHEDP rounds.

This is the problem with the AMX-13. Its not a tank, and it could be defeated by even a heavy machine gun.

[Olefin]

Which does make the AMX-13 a possible light tank that the Mexicans did have and engaged the School Brigade with (to their detriment) - ie.. they would have had ammo like that which would have stopped the Mexican attack cold

Whereas an MBT most likely may have have shrugged that off and overran them almost immediately

[kato13]

The school brigade would have had some ADATS (tracked and wheeled) and FOG-Ms correct?

In open terrain they are not the most useful, but with some shoot and scoot even MBTs would need to think twice going against those.

[RN7]

Originally Posted by Olefin

And that is why they brought Soviet Division Cuba along for the ride - i.e. to have people who had the tanks and the ability to take out M1A1 tankst

What type of tanks and ATGM's was Soviet Division Cuba using? A T-72 tank with a 125mm gun cannot defeat the frontal armour of an any M1 Abrams, even with an armor piercing fin stabilized discarding sabot with depleted uranium round. Only the very latest Soviet anti-tank missiles would even damage yet alone defeat an M1A1.

[Rainbow Six]

Originally Posted by RN7

This is the problem with the AMX-13. Its not a tank, and it could be defeated by even a heavy machine gun.

I think that's a point in its favour in this particular scenario where we're looking for something that's not overpowered and that the Mexicans might plausibly have bought.

Originally Posted by Olefin

FYI has anyone else read Trial By Fire - Harold Coyle's book about a US Mexico war?

Yes, but it was a long, long time ago so I don't really remember any of the details.

[Olefin]

Originally Posted by kato13

The school brigade would have had some ADATS (tracked and wheeled) and FOG-Ms correct?

In open terrain they are not the most useful, but with some shoot and scoot even MBTs would need to think twice going against those.

Have to look at my US Army Vehicle Guide when I get home - I think the ADATS but not sure on the FOG-M

[Olefin]

Originally Posted by RN7

What type of tanks and ATGM's was Soviet Division Cuba using? A T-72 tank with a 125mm gun cannot defeat the frontal armour of an any M1 Abrams, even with an armor piercing fin stabilized discarding sabot with depleted uranium round. Only the very latest Soviet anti-tank missiles would even damage yet alone defeat an M1A1.

Per the canon they had T-72's (Red Star Lone Star) - but if I remember right the 49th wasnt an all M1 unit - again have to look at my US Army Vehicle Guide when I get home (unless you have one handy)

[RN7]

Originally Posted by Olefin

Per the canon they had T-72's (Red Star Lone Star) - but if I remember right the 49th wasnt an all M1 unit - again have to look at my US Army Vehicle Guide when I get home (unless you have one handy)

Both 1st and 2nd edition has the 49th armored division with five tank battalions (2 M1A1, 2 M1 and 1 M60A3). The orbat for 2000 has them with 1 M1A1, 8 M1, 4 M60A3, 7 Stingray and 3 LAV-75.

[RN7]

Originally Posted by kato13

The school brigade would have had some ADATS (tracked and wheeled) and FOG-Ms correct?

In open terrain they are not the most useful, but with some shoot and scoot even MBTs would need to think twice going against those.

From American Combat Vehicle Handbook

"With the outbreak of hostilities with Mexico in 1998, the brigade was activated as a troop unit, using its available mix of weapons to create unorthodox operational units. Infantry was drawn from basic training camps at Fort Bliss and attached to ADA gun batteries (PIVAD and Diana) to create heavy machinegun combat teams. Because the brigade had no organic field artillery, it relied heavily on infantry mortars and developed its own doctrine for employment of ADA gun systems in the indirect fire role.

The School Brigade was able to hold the Fort Bliss area against repeated attacks, but was soon surrounded. Fighting its way free of the encirclement, the brigade retreated north, evacuating its equipment, personnel, and dependents through New Mexico. Once across the Canadian River, the brigade linked up with elements of the XC U.S. Corps in Oklahoma. In January of 1999, the School Brigade was attached to 49th Armored Division, with which it has served since."

[kato13]

Originally Posted by Olefin

Have to look at my US Army Vehicle Guide when I get home - I think the ADATS but not sure on the FOG-M

It is actually in the 2nd ed Heavy Weapons Sourcebook. So it is not listed in unit assignments but it is US army weapon.

[Olefin]

Thank you for the information RN7!

One thing that the Soviets did have was helicopter gunships - they are mentioned in Red Star Lone Star (if I remember they didnt mention exact numbers or types but it was definitely plural as in more than one or two) - one of the prime reasons to get the refinery was that it could produce avgas -and put those grounded gunships back into the air

That could explain how the Soviets beat the 49th - i.e. they had gunships with anti-tank weapons and fuel to put them in the air - and the 49th may not have had any by the time helos of their own by the time they encountered the Soviets - which if I remember right was in 1999 sometime

definitely would make the T-72's more survivable if the 49th is getting their heads handed to them by gunships and is busy maneuvering to engage them or throw off the missiles and as a result allows the Soviet tankers to get into position to not take on the M1's frontally

thus possibly explaining how a single Soviet Motor Rifle Division stops a five battalion armored division cold

The Cubans has armed Mi-24 and Mi-8 gunships - those definitely could have tipped the odds for the Soviets if the US ones are grounded from lack of fuel

[kato13]

Originally Posted by RN7

From American Combat Vehicle Handbook

"With the outbreak of hostilities with Mexico in 1998, the brigade was activated as a troop unit, using its available mix of weapons to create unorthodox operational units. Infantry was drawn from basic training camps at Fort Bliss and attached to ADA gun batteries (PIVAD and Diana) to create heavy machinegun combat teams. Because the brigade had no organic field artillery, it relied heavily on infantry mortars and developed its own doctrine for employment of ADA gun systems in the indirect fire role.

The School Brigade was able to hold the Fort Bliss area against repeated attacks, but was soon surrounded. Fighting its way free of the encirclement, the brigade retreated north, evacuating its equipment, personnel, and dependents through New Mexico. Once across the Canadian River, the brigade linked up with elements of the XC U.S. Corps in Oklahoma. In January of 1999, the School Brigade was attached to 49th Armored Division, with which it has served since."

The DIana battalions (will double check PIVAD) also had ADATS. 2ed also mentions 4 of the M1 based laser ADA system being at fort bliss.


Edit PIVAD equipped units had the Roland. so not useful as anti armor.

[Olefin]

Ok how many people think that this subject may be one of the most fascinating and challenging ones there is on the board as to coming up with a realistic OOB for the Mexican Army at the time of the invasion?

I would vote yes for sure

[Raellus]

I don't think that you need tension between the U.S. and Mexico to justify a major arms purchase, even one including light tanks. And I don't think that the U.S. would be particularly troubled by the purchase of a few dozen, older, practically obsolete models. Yes, the U.S. might be upset that Mexico isn't buying American, but if the purchases take place after the Soviets invade China, the U.S. (gov't and arms corporations) would be too preoccupied with providing weapons to the Chinese to care.

I haven't heard much about its status lately, but in the '90s, Mexico was fighting an insurgency against a guerrilla group called the Zapatistas in its Chiapas state. Perhaps the arms buy was part of an attempt to quash this rebellion. Perhaps, Guatemala was believed to be aiding and abetting said rebels. Perhaps the Mexican government was trying to pick a fight with Guatemala in order to distract its own population from various domestic issues (poverty, corruption, etc.).

And tanks- especially light tanks- wouldn't necessarily make it that much easier for the Mexicans to overrun the School Brigade, for example. There are lots of historical examples of well-trained, experienced, well-led infantry, without its own armor, of holding off a force equipped with armor for a couple of days or three.

[dragoon500ly]

Originally Posted by RN7

This is the problem with the AMX-13. Its not a tank, and it could be defeated by even a heavy machine gun.

Actually the AMX-13 is a perfect example of a light tank from the post WWII era.

When you consider a tank design, picture a triangle, one point is maneuverability, the second is firepower and the third point is protection.

The AMX-13 has excellent maneuverability and decent firepower, protection is poor. But it was designed for a reconnaissance role. When I was stationed in Germany, during the maneuvers that light tank could run rings around a M-60A1, and if it could get close enough it's cannon was a decent threat against flank armor. The turret also gives this tank an advantage, the cannon is mounted fairly high, and from the front it is a narrow design. This allows the AMX-13 to occupy a hull down position and reveal very little of its turret, coupled with good camouflage, makes the blasted thing very hard to detect.

It's ability to pour a burst of 3-6 rounds and then run away, does make it a threat.

But remember, it was designed for the European battlefield.

During the Six Day War, the IDF fielded three battalions of AMX-13s, due to the shortage of MBTs, they used the -13s as main battle tanks and they suffered heavy losses when used outside their designed role.

So the Mexican Army buying light tanks, very possible, equally possible is their suffering heavy losses, especially when going up against TOW/Dragon/Tank Breaker/Hellfire. Toss in M-48A5/M-60A3/M-1, and you have a nasty little surprise for the Guard and Reserve units, but one that would be quickly worn away by battlefield and maintenance losses.

[dragoon500ly]

Originally Posted by Rainbow Six

Yes, but it was a long, long time ago so I don't really remember any of the details.

If I remember correctly, didn't the author use a Nicaraguan armor brigade equipped with T-72s?

[Raellus]

Originally Posted by dragoon500ly

So the Mexican Army buying light tanks, very possible, equally possible is their suffering heavy losses, especially when going up against TOW/Dragon/Tank Breaker/Hellfire. Toss in M-48A5/M-60A3/M-1, and you heavy a nasty little surprise for the Guard and Reserve units, but one that would be quickly worn away by battlefield and maintenance losses.

This. Even early-model M72 LAWs and old recoilless-rifles just taken out of mothballs would be able to defeat any of the tanks we've mentioned so far, including the AMX-30 and TAM.

What these AFVs do is give the Mexicans increased firepower and mobility. Coupled with surprise, this upgraded Schwerpunkt explains the dramatic early success of the Mexican invasion, and goes a little way in explaining why the Mexicans still hold territory in the U.S. in 2000 and beyond.

[dragoon500ly]

Originally Posted by Raellus

This. Even early-model M72 LAWs and old recoilless-rifles just taken out of mothballs would be able to defeat any of the tanks we've mentioned so far, including the AMX-30 and TAM.

What these AFVs do is give the Mexicans increased firepower and mobility. Coupled with surprise, this upgraded Schwerpunkt explains the dramatic early success of the Mexican invasion, and goes a little way in explaining why the Mexicans still hold territory in the U.S. in 2000 and beyond.

Concur, by the time of the invasion, you would have the bottom of the barrel scraping to defend the U.S. southwest.

This is why I argue that the 49th Armored gets shipped to Europe, this leaves no significant armor force to cover the New Mexico, Arizona, Texas front until the 50th Armored gets shipped down from Ft Knox, Ft Drum to act as reinforcement, and since the 50th AD had so many problems with its training...now the Mexicans get a slim edge over the American armor.

[Olefin]

Originally Posted by Raellus

This. Even early-model M72 LAWs and old recoilless-rifles just taken out of mothballs would be able to defeat any of the tanks we've mentioned so far, including the AMX-30 and TAM.

What these AFVs do is give the Mexicans increased firepower and mobility. Coupled with surprise, this upgraded Schwerpunkt explains the dramatic early success of the Mexican invasion, and goes a little way in explaining why the Mexicans still hold territory in the U.S. in 2000 and beyond.

I would agree with you there Raellus - and keep in mind that the Germans broke thru the French in 1940 and achieved victory using tanks that in many ways were inferior to the ones the French had both in terms of quantity and quality.

And one big reason for the success may be who they are facing - i.e. a bunch of light infantry divisions converted from training divisions, military police units, a widely scattered National Guard infantry division that hadn't seen any fighting yet (i.e. the 46th), a rebuilt National Guard division that was equipped with a grab bag of armor including Engineering tanks masquerading as the real thing (the rebuilt 40th minus one of its brigades) and a single National Guard tank division that wasnt there to face the initial attack (the 49th) and hadnt seen any combat yet

and most likely with very limited air support due to fuel shortages and lack of aircraft

probably the best units they initially faced were the School Brigade and the 177th (which isnt even in the canon) and they were heavily outnumbered

all of whom would be facing fuel and ammunition shortages and major communication and logistics issues from the effects of the nuclear attacks

i.e. in other words they didnt face the best the US had at the top of their game - if they had that invasion would have been stopped cold in its tracks

[Olefin]

One other factor that might have also lead to their success may have been the Americans underestimating them

I.e. that it was just the Mexican Army how hard can they be?

Very hard to quantify that for us with what we are doing but if the writers took that approach you could see them figuring the US units would be too confident and approach a fight without really considering that the Mexican Army might be better equipped and motivated than they gave them credit

If you look at Trial by Fire (the book I mentioned earlier) the US units feel that way when they encounter Mexican units - and as a result take much heavier casualties than anyone expected

[StainlessSteelCynic]

On a side note, I've been trying to get better info on those Argentinian upgraded Shermans.
Even looking through Jane's for the relevant years there's not a lot of information but I do have the following for the powerpack that was used.

Paraphrasing from Jane's Armour and Artillery 1986-87, page 950

Poyaud 520 series engines developed to a requirement of the French army although weren't used by the French army. Based around a common cylinder of 135mm bore and 122mm stroke. The modular construction of the engines allowed them to be offered in many configurations for many different vehicles (including Soviet) chiefly naturally aspirated (NS suffix), turbo-charged (S1 suffix), turbo-charged with charge-air intercooling (S2), turbo-charged with oil-cooled pistons and intercooling (S25) and turbo-compounded using the "Hyperbar" process (S3).
All variants were apparently direct injection and water cooled.
It seems as though the engines could be supplied to a buyer in kit form for assembly at their point of destination.

The Argentinian upgraded Shermans were fitted with the 520 V8 S25, meaning they used the turbo-charged, oil-cooled piston, intercooler version. This developed 2500rpm at 570HP (420kW). It looks as though this engine was designed for US vehicles of the post-WW2 era e.g. M4 Medium, M36 and M41.

I haven't found anything to state these were petrol/gasoline or diesel except for the article I originally linked. I'm inclined to think diesel because they were all direct-injection but that's just a guess. I'm hoping someone with a better knowledge of engines than me (which pretty much means just about everybody!), can make a better assessment of that.
What all of that means for game stats I'll leave (again!), to people with a better understanding of engines.

I haven't found anything specific about the 105mm gun except for the article I linked that states it was a French gun. Given that the French had tested a 105mm on the AMX13, they certainly would have had the tech knowledge for designing one suitable for refitting to the Shermans.

[The Dark]

Originally Posted by StainlessSteelCynic

On a side note, I've been trying to get better info on those Argentinian upgraded Shermans.
Even looking through Jane's for the relevant years there's not a lot of information but I do have the following for the powerpack that was used.

Paraphrasing from Jane's Armour and Artillery 1986-87, page 950

Poyaud 520 series engines developed to a requirement of the French army although weren't used by the French army. Based around a common cylinder of 135mm bore and 122mm stroke. The modular construction of the engines allowed them to be offered in many configurations for many different vehicles (including Soviet) chiefly naturally aspirated (NS suffix), turbo-charged (S1 suffix), turbo-charged with charge-air intercooling (S2), turbo-charged with oil-cooled pistons and intercooling (S25) and turbo-compounded using the "Hyperbar" process (S3).
All variants were apparently direct injection and water cooled.
It seems as though the engines could be supplied to a buyer in kit form for assembly at their point of destination.

The Argentinian upgraded Shermans were fitted with the 520 V8 S25, meaning they used the turbo-charged, oil-cooled piston, intercooler version. This developed 2500rpm at 570HP (420kW). It looks as though this engine was designed for US vehicles of the post-WW2 era e.g. M4 Medium, M36 and M41.

I haven't found anything to state these were petrol/gasoline or diesel except for the article I originally linked. I'm inclined to think diesel because they were all direct-injection but that's just a guess. I'm hoping someone with a better knowledge of engines than me (which pretty much means just about everybody!), can make a better assessment of that.
What all of that means for game stats I'll leave (again!), to people with a better understanding of engines.

I haven't found anything specific about the 105mm gun except for the article I linked that states it was a French gun. Given that the French had tested a 105mm on the AMX13, they certainly would have had the tech knowledge for designing one suitable for refitting to the Shermans.

The Poyaud 520 is a V-8 diesel engine. The Sherman Repotenciado's gun was a license-built version of the 105mm from the AMX-13, the coax was a MAG-58, and the pintle MG an M2HB. Many of them were rebuilt Sherman Firefly, since England repaid some of its debt to Argentina by giving them Shermans at scrap metal cost. To make room for the gun upgrade and increased shell size, it had no radio operator (not a big deal with modern radios) and no loader (big deal, since it didn't have an autoloader). It's not really relevant to this discussion, but a lot of the Shermans in Saving Private Ryan were Repotenciadoes.

Paraguay is (or was, as of 2015) still using three of them as ceremonial vehicles for the Presidential Escort Regiment. The three in use are SN 15919 (built by Baldwin in September 1943), SN 40351 (built by ALCO in November 1943), and SN 6057 (built by Chrysler in November 1942).

There were also Chilean Shermans (which Paul has listed under the Israeli tanks, since they're modified Israeli Shermans). They bought Israeli M-50 and M-51 Shermans and re-engined them with Detroit Diesel 8V71T engines. The M-51 (105mm) was kept with its existing armament, but the M-50 (75mm) was re-armed with IMI's 60mm HVMS cannon (which was also used in Chilean Chaffee tanks).