There are men and women of the Armed Forces that have been in need of a better weapon than the 45. It's about time for the change. For those that used it you know how badly it performed. For those that crawled into a tunnel in Vietnam, and had to use it in that tunnel, then you know what it did to your hearing. You also know it was best used for pistol wiping than for firing.
The 9mm has plenty of power, I traded my 38 for a newer 38/357 years ago, and then when the 9mm came along I traded my service revolver for the automatic. It saved my life many of times. I didn't like the 44cal or the 45cal as a police officer. I hated the 45cal in the Army, so I wrote my Father and asked him to send me my 38, I used it in Nam and it was a far better choice than the 45 for me.
I have used the 9mm Beretta, 45 cal. Sig Sauer and the .40 cal. sig Sauer. The best all around weapon is the .45 cal. Sig Sauer. It is accurate and has real knock down power (1 shot) capability, and with the 10 round magazines it has more than enough firepower. The .9mm is a small, light round than travels to fast and inflicts a small wound channel. The.40 caliber is adequate, but the pistol grip is too small for those of us with larger hands, which makes it harder to control. A larger pistol grip and an extended magazine would be ideal.
The 9mm is not powerful enough when dealing with drugged hostiles. Many times a 9mm will not stop an attacker even with a fatal chest shot, that means head shots only. Hopefully the military will accept the new HK45 as the standard combat sidearm, .45 ACP has the knockdown power needed for use against hostiles under the influence of narcotics. The 9mm pistol that berretta has introduced to the armed services is a very good pistol.
However, far down in the dirt knock-down power, the caliber 43 pistol or revolver is better. Better yet, using a 44 magnum caliber is even better providing the person firing it can control the recoil properly.
Having carried both the M9 and 1911A1 in combat I guess I am qualified to have an opinion. Not only is the M9 underpowered but the issue magazines are junk. I had three failures to feed malfunctions with brand new out of the box GI mages. That problem went away when I purchased some after market mages. The underpowered problem will not go away. We need to return to a .45 or even a .40 caliber handgun.
Go with the 45HK and be done with it, but like one of the post said, it the money, give the soldier a slang-shot it cost less, and they would if they could. The .45 is a better choice. The 9mm is underpowered and the .40 has about the same ballistics as the .45. When in the position of needing what will get the job done, nothing is better than a .45.
Victor Epand is an expert consultant for http://www.WarGear.info/ . WarGear.info carries the best selection of military clothing , war gear, and combat accessories on the market.