I said.....
.257 much lighter than .270, and flatter shooting
Miss typing on my part. I dont know what you mean by .257.
That sharing only started in 1960s, when the US released weapons to NATO air assets.
Without F104, the air weapon sharing could not happen. Catch 22.
Sure it would. The US actually wants lots of nukes and the alternative to the US providing the nuclear weapons is either the Europeans build their own or France or Britain provides them or the US puts more Squadrons into Europe while fighting Vietnam and still has the political problem. Now there is a serious political issue that the US will not want nukes deployed without its consent or knowledge if it possibly can but that's a technical issue of how you operate the PAL.
Now using US aircraft the whole thing easier but if you use Mirage no reason not to use French nukes. with French PAL which forever excludes the US from the Euronuke decision process.
Without penetrations, the flammable high pressure hydraulics would be much less a problem.
But the US cannot make the armour. It does not exist outside lab scale experiments. Everyone with a decent scientific base and interest in defeating HEAT rounds knows the issue and the solution a basic composite form has been known since WW1 to offer much better protection. Soviet Composition K vs kinetic rounds is used on the T64 but then 120mm guns. The problem all along is how do you make something that works at the size and scale needed to equip a tank fleet. If the US cannot do it in 1960 then it probably cannot be done then, late 60s it probably could have been that means the US does not deploy its next gen MBT until then or more probably early 70s as you have to run up design and for a tank using it and production of the armour.
IDF were actually wanting 110mm as a 1:1 replacement of 105mm. Both rounds could adopt APDSFS with fixed rounds and not disrupt storage.
Yes they were the problem is not that it could not have been developed, the Israeli offer was actually to develop the HEAT round for a then experimental 110 ROF gun the British were developing. The underlying problem is in 1974 the Germans produced the 120mm smoothbore. And they are going to use it.
Just about the only way it comes into service is if the FMBT programme of the early 70s is shifted back in time. Basically no MBT 70 and its nonsense of a gun missile launcher which is technically not viable in the 60s or early 70s and you end up with a Burlington armoured AFV available around 1970 and the 110 is offered as a replacement for the existing 105, but not 105 ammo stocks. But the 105 L7 is perfectly good at taking on soviet tanks into the 80s and the 120 L44 is intended to deal with the net gen soviet tanks.
The big drivers are the US and German requirements, If you have an Anglo German collaboration there is probably a better cultural fit in the development than with the americans and you get something earlier that is better than what was around in the early 70s. But its difficult to see why either party would ditch their 120mm in favour of a less developed 110 gun and ammunition as it will likely be available with a 105 version to make use of existing ammo stocks and designed to be upgraded to either 120mm.
The F11-1f never goes beyond prototype and would have the same issues, you are changing a single seat fighter into a nuclear bomber/FGA and there will be issues. Maybe not as many as with the 104 but still you have a growing air force attempting to maintain an advanced aircraft there will be a lot of problems.