I have contacted quite a few barrel manufactures about producing some 9 m.m. and .40 S&W rifled blanks because
they can do the gun drilling and button riffling more efficiently than I can.
They seem to prefer to use alloy steels (4140 types), where I’m asking for 400 series Stainless Steels.
I am still waiting for more quotes to come in.

In the interim I found a Bar-Sto barrel in 9 m.m. X 23 m.m. from a forum member and purchased it.
The reason is partly that I wanted to see the quality, fit and finish of a Bar-Sto (Drop-in?).
The other reason is that I had found 7 - 50 round boxes (at a good price) of 125 gr. Winchester Silvertips HP's in 9 m.m. X 23 m.m
with the thoughts of de-capping them to use the brass for my .356 TSW reloads.
Well, after de-capping one box, what a pain in the butt that was.
I got to thinking about shooting the ammo rather than de-capping them and happen to find the Bar-Sto barrel by chance.
Was I ever surprised when I received it? It had to be re-worked quite a bit, it was definitely not a "drop-in".
The barrel locking lug in front of the chamber hood that seats into the slide when in battery was not cut deep enough by .024” on the diameter compared to my factory barrels.
The location of the breech face lug on top was binding on the slide breech face and was also way out of square to the thru bore.
I ground .010” to fit leaving .002” clearance during lock-up. Stock S&W barrel and slide seem to be .004-.008 clearance.
The .204 diameter pin on the slide lock lever that holds the assembly all together and contacts an area under the bottom lug and
controls the position that the slide locates forward lock-up relative to the back of the frame was off.
It had to be reground with a matching radius, I had to push it back an additional .032” for the back of the slide to line up.
The chamber was also way out of spec and it was re-bored in a CNC Lathe to SAAMI Specs.
Now it's ready to go to the range.

Some pictures here:
1006/1026/1046 in 9mm X 23mm / .356 TSW

I will update as needed, best regards,
BM1