I read through pages, searched for info, surprised that I didn't find much information in a specific post about the differences in shooting between the MK40 and MK9.

Can someone tell me about the recoil, handling, 2nd.. shot comparison, any differences between the two guns??

- The only real downside on the 40 I can think of is round count but I've only shot the K40 so I have little for a direct comparison in regards to recoil differences.

- My only frame of reference in a gun this size is the comparison between my Glock 26, that I recently converted to a 27 40 S&W- which is a approx 2 oz. lighter than an MK.

- I carry Underwood Extreme Defense rounds- there's somewhat significant loss between the calibers in muzzle energy (102 fp) see below.

- The recoil of this Underwood round is noticeably lighter because it's a smaller projectile, so the difference between shooting a standard HST 9mm and an Underwood .40 are less dramatic than a typical .40 S&W round.

Info from webs:
Underwood Extreme Defender- Technical Information:


  • Caliber: 40 S&W
  • Bullet Weight: 115 Grains
  • Bullet Style: Lehigh Defense Xtreme Defense
  • Case Type: Ducta-Bright 7a Nickel Brass

Ballistics Information:


  • Muzzle Velocity:1400 fps
  • Muzzle Energy: 500 ft. lbs.
  • Penetration:17 3/4 inches

Underwood Extreme Defender- Technical Information:


  • Caliber: 9mm Luger
  • Bullet Weight: 90 Grains
  • Bullet Style: Lehigh Defense Xtreme Defense
  • Case Type: Ducta-Bright 7a Nickel Plated Brass

Ballistics Information:


  • Muzzle Velocity:1400 fps
  • Muzzle Energy: 392 ft. lbs.
  • Penetration: 15 in.