James, straight from the owners manual -- "Although this Kimber firearm is capable of functioning with +P ammunition in the appropriate caliber for the firearm, a steady diet of +P ammunition may affect the wear characteristics, shorten the life and endurance of your firearm, and necessitate more frequent maintenance and replacement of parts. Do not use +P+ ammunition.

As others have said this is rated for +p ammo. But not many, actually can't think of any manufacturer that says +p+ is safe to shoot cause there's no saami standard for +p+ so it's hard for a manufacturer to say yes this is safe when there's no cut off limit for that specific round. They have plenty of defense ammo that is more than adequate like federal hst, and speer gold dot. I'd stick to standard pressure with occasional +p usage. Cause using +p regularly can wear out gun parts quicker than standard velocity ammo. Hope this helps.

James, you can shoot +P max 9mm loads. Stay away from +P+. +P loads generally require 4 inches of barrel length to completely burn the extra powder Sir. In shorter barrels, you will only get increased recoil, muzzle blast and sight recovery time and not as much performance increase as the full additional fps that the +P and +P+ numbers suggest. Especially in a shorter barrel. Standard 9mm quality JHP works just fine and will yield more accurate follow up shots if needed. Cheers and stay safe!

Buffalo bore 9mm comes in 2 varieties, +P, and +P+, the Kimber Micro 9 is rated for +P, but Kimber does not recommend shooting +P+, and while it is rated for +P it will not be pleasant to shoot out of such a light small gun. You can shoot standard pressure loads like Tech’s high performance “Full Stop” 124-grain standard P load in Shell Shock Technology cases, or standard pressure federal 124 gr HST, and either of these will have sufficient stopping power but be more much more manageable.