I’m looking for a barrel to convert a1.0 MP 40 to shoot 9mm. I can’t seem to locate one currently. Are they still made by anyone?

Not cheap

Smith & Wesson M&P Barrels - Bar-Sto

Have you lookrd here ?
Lone Wolf Distributors | AlphaWolf Barrels for M&P Shield 40-9 conversion barrel stock length | Length 3.10 inch, 79 mm

I was going to suggest Storm Lake Barrels, but their website is down or gone, and most retailers show Storm Lake M&P barrels to be either out of stock or discontinued. Anyone know if they are still in business? If they've gone out of business, it's too bad, because I have one of their .357 SIG conversion barrels in my 1.0 M&P 40c, and it's excellent.

BTW, Apex also makes conversion barrels.

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What, me worry?

I would suggest KKM Precision.

Check Midway

I have two KKM Precision barrels and have been very happy with their performance!

Yep, KKM is quality and they list conversion barrels. My only experience with them was for a 10mm to .40 for my Glock 40. Perfect fit and function.