M&P40 Shield reloads

[mewoodham]

I bought an M&P 40 Shield, but I am not yet set up to reload 40 ammo. Using 165 grain factory ammo it kicks like a wounded buffalo, so hard that it is uncomfortable to shoot. My Lyman loading handbook lists several different possible bullet weights ranging from 135 to 180 grains. The question is, will the pistol operate properly (slide mechanism) with the lighter loads and bullets? And will lighter loads and lighter bullets lessen the recoil?

[rsrocket1]

It will, but you will need to work down your loads to see what combination will produce comfortable loads that will still operate the action. With the FS gun, I load 180g 40 cal bullets with 3.0g Red Dot or Clays and get equivalent recoil to 1100 fps 120g 9mm loads (same gun, just using the 9mm barrel). I can work down to 2.7g, but at 2.5g the slide fails to lock on the last round about 25% of the time so I just keep it at 3.0g. At that load, the shooting is soft enough.

[dullh]

Reload .40 S&W with extreme caution.

.40 in general, and .40 reloads in particular, are extremely susceptible to the phemonenon known as the "KaBOOM'. The commonly accepted cause of this condition in Glocks is an unsupported case head. The more common cause, applicable to all pistols chambered in .40, is when the bullet is pushed farther into the case upon chambering. This creates an over-pressure condition that is extremely dangerous. Since .40 headspaces off the case mouth, use a taper crimp on the case as your final handloading step. The taper crimp will inhibit rearward movement of the bullet into the case upon chambering. Taper crimp dies for .40/10mm are readily available.

Handloading .40 is not recommended if you are new to handloading. Exercise caution even if you're experienced handloading more forgiving cartridges.

Cast bullets can be used to save money...the M&P is not a Glock, so the cast bullet prohibition does not apply.

Best.

[mewoodham]

Thanks for the input and insight. I appreciate the help.