Gents,
Not to drag this thread out again...but here goes!

I was just reading some old Kynoch adverts last night.
In their ad for the then new nickel based bullets (which I believe was the first use of a "gas check") they mention the high pressures encountered when using the "solid nickel bullet".

Now, this leads me to believe that perhaps this mono idea was attempted over a century ago with largely the same concerns arising then as there are now.

Just food for thought...