140mm main gun for tanks?

[FromMyColdDeadHand]

Only 70%? It better be pretty leathal since you're turning a tank into a six gun shooter....

Look at those round sizes/lengths? At what point do you have to have an assistant loader and a crazy sized magazine?

[soulezoo]

Seeing the picture comparison, it's not hard to see where that 70% is coming from. It's like comparing a .338 Weatherby mag vs a .22-250.

I agree with the above, there's going to be some serious compromises with internal storage and feeding. After 10 minutes of firing, it's going to need resupply. Logistics will necessarily change.

[Slater]

The current French Leclerc tank uses an autoloader. That may (or may not) be an issue with this new round.

[soulezoo]

This is definitely going to have to use an auto-loader. It’s going to take some creative engineering for the loader and for ammo storage

[Averageman]

There is a point of diminishing return on ammunition capabilities vs the size of the entire cartridge.
You're going to be severely limiting the amount of ammunition you carry in your ready and semi-ready racks. You're going to deal with engineering and auto-loader which is a maintenance heavy piece of equipment. If you go with an auto-loader you're now losing 25% of your crew. The entire turret needs a redesign, plus you're limiting the available space inside the turret even more. You're likely, due to increased weight and mass inside the turret to need a new power train to push that Tank above speeds of 30 mph.
Unless your optics, both day and night support the 140mm Maingun, what is the advantage?
You're kind of hoping for a pool table flat piece of un-obscured piece of ground to fight on, and that's just not likely to happen in most of central Europe.
Just because you can something doesn't mean it is needed or even smart. If you really wanted to improve the Abrams you would co-axially mount an M2 HB caliber .50.

[vicious_cb]

If this actually results in a production contract, will the Abrams follow suit?


"Nexter has fit a 140 mm gun on a Leclerc main battle tank (MBT) to gather data for the Franco-German Main Ground Combat System (MGCS) programme to replace it and the Leopard 2, Jane's learned at the International Armoured Vehicles (IAV) 2019 conference held in London on 21-24 January.

This is understood to be the first time that a 140 mm gun has been successfully integrated onto a 50-tonne MBT and conducted over 200 firings. It is expected to provide a 70% increase in firepower over a NATO standard 120 mm gun."


https://www.janes.com/article/85934/...on-leclerc-mbt

No, because there is no way a larger main gun is going to fit into the existing Abrams gun mantlet form factor since they couldnt even get the 120mm L/55 to work. The entire turret would have to be redesigned, while you are doing that you might as well design a whole new tank. The closest thing we have to replacing the current 120mm L/44 is the XM360 from the canceled FCS program thats just a lighter 120mm with datalink.

[sundance435]

No, because there is no way a larger main gun is going to fit into the existing Abrams gun mantlet form factor since they couldnt even get the 120mm L/55 to work. The entire turret would have to be redesigned, while you are doing that you might as well design a whole new tank. The closest thing we have to replacing the current 120mm L/44 is the XM360 from the canceled FCS program thats just a lighter 120mm with datalink.

Yeah, highly unlikely this would work for an Abrams, even if they designed a whole new drop-in turret. It would probably add anywhere from 6-10 tons to the Abrams, which already isn't the quickest MBT out there and has documented issues on roads that aren't the greatest. Main guns using traditional tank shells are close to maxed out. You'd have to move into rocket assisted shells to get to the next level...at which point you've basically just built another self-propelled gun.

Also, Re: the Russian 125mm, I've read that the 120mm smoothbore on the Abrams and Leopard II outperform it. The increase of 5mm doesn't equate to a performance increase, at least with their current guns/munitions.

[Averageman]

No, because there is no way a larger main gun is going to fit into the existing Abrams gun mantlet form factor since they couldnt even get the 120mm L/55 to work. The entire turret would have to be redesigned, while you are doing that you might as well design a whole new tank. The closest thing we have to replacing the current 120mm L/44 is the XM360 from the canceled FCS program thats just a lighter 120mm with datalink.

Yeah, highly unlikely this would work for an Abrams, even if they designed a whole new drop-in turret. It would probably add anywhere from 6-10 tons to the Abrams, which already isn't the quickest MBT out there and has documented issues on roads that aren't the greatest. Main guns using traditional tank shells are close to maxed out. You'd have to move into rocket assisted shells to get to the next level...at which point you've basically just built another self-propelled gun.

Also, Re: the Russian 125mm, I've read that the 120mm smoothbore on the Abrams and Leopard II outperform it. The increase of 5mm doesn't equate to a performance increase, at least with their current guns/munitions.

A lot of truth in the above.
There would have to be a near complete redesign.

[hotrodder636]

Oh $hit....picture is worth a thousand words...i can see the 70% increase.

Only 70%? It better be pretty leathal since you're turning a tank into a six gun shooter....

Look at those round sizes/lengths? At what point do you have to have an assistant loader and a crazy sized magazine?

[FromMyColdDeadHand]

Part of me wonders if this is to goad the Russians to going to a 145mm....