Unless they are steel core, they aren't different. NATO specs do include a steel core round which can't be sold to US consumers, but other than that the ammo isn't different.
Other than making steel core bullets themselves, the equipment is the same for manufacturing even the steel core ammo.
...we should be able under any situation to handle our own production of ammunition.
How would you suggest going about doing that? Are you planning on having ammo factories built and maintained, just waiting to produce whatever ammo we might need for "any situation"?
I suppose we should have the capacity to build, bombs, tanks, planes, guns, ships, and everything else we might possibly need for "any situation"?
We would need to not only build, but maintain those factories. We would also need to train workers and keep have them ready and able to step up and manufacture such products to meet our needs for "any situation".
So who is going to pay for all of this? Who is going to run all of it? Talk about growing the government bureaucracy.
We need to maintain reasonable stockpiles of ammo both in the US and staged in areas where we might need it.
There are ways to encourage manufactures to maintain a higher capacity.
What we need to do is encourage the civilian use of military rounds so that the manufacturers have reason to maintain the ability to produce more ammunition.
Basically we need to do the exact opposite of what the gun grabbing liberals are trying to do. We need to encourage civilian use of guns that fire the same cartridges as are commonly used by our military.
We need to reduce the tax and bureaucracy that ammo manufactures face so they can sell ammo at a competitive price and therefore keep quantities up. The exact opposite of what liberals are trying to do.
However, what we should not do is have the government create factories that sit idle, just in case we might need them.