There's a decades-old argument about which pistol round is better that stems from a more basic argument about terminal ballistics – which is just a fancy term for what happens when bullets hit living things.
The two sides of the argument are between those who believe fast, lightweight rounds do more damage, and those who believe heavy, lower-moving rounds impart more energy and "stopping power" on the target.
Listen to the WATM podcast to hear our veteran hosts and a weapons expert discuss the M9 and why ammo matters:
Given its history of weapon adoption, it seems the Army is a proponent of the fast, lightweight department. First it swapped out the 7.62mm M14 for the 5.56mm M16, then the .45 1911 for the 9mm M9. While many agree with the first change (sorry M14 lovers) some still think the M9 should never have been adopted without changing the ammunition recipe beforehand.
Full metal jacket ammo is really great for sending rounds through paper, but its aerodynamic and hydrodynamic design makes it zip through tissue without dumping most of the energy behind it into the target. Shot placement can compensate for this by hitting harder stuff like bones or vital organs, but under the stress of returning fire, that's damn tough for even the seasoned Delta operator to land perfect hits with a sidearm.
An M9 service pistol's magazine rests on the firing line next to a scoring sheet during a pistol qualification course aboard Camp Lejeune, N.C., April 7, 2015. (U.S. Marine Corps photo taken by Cpl. Alexander Mitchell/released)
Ideally, a round will dump all of its energy into a target, which reduces the need for shot placement at the cost of reduced penetration. On a rifle, this is a big drawback. It means if Johnny-Jihad is hiding behind a plywood shack, the rounds will expand in the wooden walls and lose most of their power. With a sidearm, most shooters aren't trying to blast bad guys through walls – it's a weapon of last resort.
So when a trooper needs to draw his M9, he shouldn't have to worry about the bullets failing to stop his attacker.
If the military wants to put the M9 on even-footing with the M1911's fight-stopping power, it might only need to swap out the M882 round with the good stuff being issued to American law enforcement officers.
Heck, Rangers have been running heavier, jacketed hollow-points for years. This isn't news to the brass.
A little more than a year ago, the Army declared its Modular Handgun System should be able to operate with special ammunition like jacketed, hollow-point rounds. The so-called XM17 is slated to replace the M9.
In fact, one recommendation is to replace the lightweight 112gr M882 FMJ cartridges with heavier 147gr expanding hollow-point rounds like those employed by Ranger elements during combat operations. These heavier rounds don't just expand better in their targets, they're also subsonic.
Mass Communication Specialist 3rd Class Jesse Paquin, assigned to Expeditionary Combat Camera reloads an M9 pistol during practical weapons course training at Naval Support Activity Northwest Annex, July 28. (U.S. Navy photo by Chief Mass Communication Specialist Eric Dietrich)
This has two major advantageous. First, it makes them better suited to pistols and submachine guns equipped with sound suppressors. And second, it provides a more consistent flight path since the bullet doesn't go transonic.
That all said, many agree the M9 does have some serious mechanical shortcomings. Slides cracking, junk magazines in the early days of the G-WOT, and the gun's open-slide gobbling up sand all contribute to a pistol clearly not at home in desert warfare.
But with new magazines that work much better, reinforced slides and a proper maintenance schedule, many experts say the M9 beats the hell out of the 1911 it replaced — but only with proper ammo. Hague convention be damned, expanding ammunition isn't designed to cruelly maim soldiers but to drop them more reliability. Plus, these same rounds are nearly always stopped by walls, putting fewer civilians at risk in adjacent rooms.
Lastly, if you're worried about our guys getting hit with these types of rounds, don't be. Expanding ammunition amplifies the effectiveness of body armor, since both are designed to dissipate force. So as long as Joe has his body armor on, hollow points won't do any more than a standard pistol round.