You didn't say if this was a compact or a full size, but either will shoot regular 9mm. You might need a lighter spring for the full size on a compact you can remove the inner spring and it will work find. You are counting on the extractor to hold the 9mm round against the firing pin and will need to brush the chamber out good, much like shooting .38s' in a magnum. Anyone that can load 9mm can do 356tsw for you. 9x21 ammo will also work, but factory is loaded to the same power as 9mm and may need lower spring rates. I had a 9mm barrel for my full size made by the PC in the late 90s' and it was $225 back then. When they made USPSA Limited major class .40 minimum I started using my Briley Comp for Bullseye. I've used a light loaded 105gr 9mm in it ever since with no failures and good accuracy. Federal offered a Hydra-Shok personal defense round which was loaded to the same specs as 9mm +P and worked in both my full and compact guns without any spring change. Don't let ammo stop you from getting a great gun.