I request input on the best ammo for the S&W M&P Shield 40 S&W caliber for carry.

NOTE: Please see my original thread in the Smith & Wesson Semi-Automatic Pistols category, Smith & Wesson M&P Pistols sub-category, which gives more detail about what I'm looking for.

Thanks in advance.

All the brands listed in this 9mm thread are also good in the 40.
Just transpose the higher grain 9mm slugs mentioned to their 40 equivalent.
Seeking real world 9mm ammo advice for Shield

I dont have a shield I have the full size but I carry Federal HST ammo. After watching a video on youtube where it was tested in the ballistic gel and it penetrated further than a hydroshok and expanded to .73 inches, (pretty sure that was the exact number) it was also more than the hydroshok. I was sold.

Stopping Power is directly proportionate to shot placement. Seeing as NO reasonably concealable handgun caliber is really a proven one shot man stopper(short of a head shot), I would carry which ever round functions with the most consistent reliability.

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Not in Kansas anymore, Toto.

Federal HST, Hornady XTP both good for short barrel guns.