ANY good industrial supply catalog here in the USA has a large number of special thread taps and dies
and they aren't expensive. I sent a 1/4x80 tap and maybe a die to a gunmaker on this forum.
I have a selection of them I use on rare occasions such as 10x28,10x40 1/2x20 left hand,9/64 x 40
which I have used ONCE in 50 years. 5/8x32 and 7/8x16 are also in my collection.
Bob Roller