S&W M&P Compact .22

[WebSnyper]

6.) Guys at the range have asked me why I didn't get a threaded barrel. It's a $300 gun and a ton of ammo is less than a cup of joe at Starbucks! I have no plans of modifying or accessorizing past adding more magazines.
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My understanding is all versions of the M&P 22c have a threaded barrel, and they are either sold with a thread protector cap or with the suppressor thread adapter nut pre-installed. So if you don't have the version with the thread adapter, you can just buy the kit from S&W:
Product: Suppressor Adaptor Kit

Unless you already have a suppressor though, I think that you have to take the thread adapter nut off before you can remove the slide of the gun for cleaning. As such, I just leave the original thread protector cap on mine.

This is my understanding as well from reading on these, but without actual hands on.