What is the proper procedure for decocking the m9 pistol?

Answer 1

If you're referring to the US M9 pistol - the Beretta 92F - you can decock it simply by placing it on safe. The Beretta 92/M9 has a slide mounted hammer drop pin block safety which releases the hammer and blocks the firing pin so that the hammer won't strike it.

If you want to actually CLEAR the pistol, you would put it on safe, drop the magazine, pull back the slide, inspect the chamber, then release the slide.

I'd walk you through the functions check, but it's been too long..

Always point it in a safe direction before decocking. My 9mm has a decocking lever on the side, above the magazine release. Down decocks, up is the safety. You can also decock it by placing your thumb on the hammer, gently squeezing the trigger until the hammer is released, and slowly letting the hammer down. If your thumb slips off the hammer the pistol may fire, which is why you want it pointed in a "safe" direction.