Judge Dredd smartshell shotguns to hit Iraq in '09
'XM-25' wireless airburst slugs hit round corners
You can combine this with a laser rangefinder, digital three-axis inclination sensors and computer gunsights to achieve some almost Judge Dredd-style results. For instance your enemy is hiding unsportingly in a trench or behind a wall. You can ping his hide with the rangefinder, select an extra metre or two of distance on the fuze, and shoot slightly high. The grenade-slug will explode just above the target's head, spraying him with shrapnel despite his frontal hard cover. You could use the same trick to make your rounds explode right next to an enemy hiding around a corner.
Likewise, you can dial up slightly increased distance shooting at windows, thin walls, shrubbery or whatever. The projectiles will punch through to explode where you want them to, where impact-fused rounds would tend to go off too soon or too late.
The 25mm wireless airburst notion first got serious impetus as part of the US Army's Objective Infantry Combat Weapon (OICW) plan of the 1990s. This would have been a dual combo weapon, a bit like the rifles with underbarrel ordinary-grenade launchers which are common today. The 25mm smartshell gun would have been paired with an ordinary assault-rifle type shooter firing regular dumb bullets.
The snag with the OICW multi-shooter was that it came out ridiculously heavy, which put the whole thing largely onto a back burner at the Pentagon. But the 25mm smartshells were still the only realistic concept for a genuinely new kind of infantry weapon, and since 2001 the US forces have plunged into two large infantry wars. There has been more and more suggestion that the fountains of money now being poured into American military technology should try to focus a bit more on the grunts who are doing the actual fighting, rather than fighter pilots, submarine captains etc.
Thus the OICW 25mm smartgun has been turned into a standalone weapon, nowadays generally known as the XM-25 (X for experimental - it would presumably become the M-25 in line service). It is referred to variously as an Individual Airburst or Counter Defilade system.
The XM-25 dedicated airburst gun had been noodling along with the odd test here and there, but now it is said to be moving forward seriously to the point where it could be in Iraq or Afghanistan next year. This is according to the war-hacks at Military.com, who have spoken to Rich Audette, a senior Army official in charge of personal weapons.
"What we're talking about is a true 'leap ahead' in lethality, here. This is a huge step," Audette told Military.com last week.
As envisaged, the proposed M-25 would hold as many as ten 25mm smartshells in a box magazine. Its rifled barrel would let these airburst precisely out to 500m, or less accurately to 700m. Complete with computer/rangefinder/thermal-vision module the gun would weigh as much as a present day M-16 rifle+grenade launcher combo, and have recoil similar to an ordinary 12-bore shotgun.
The M-25 would seem on the face of it to be at a disadvantage in the closeup scuffling nowadays so common for Western footsoldiers, but possibly not. Though hefty, it is short and handy - about the length of an existing M-4 carbine with stock telescoped. Though the barrel is rifled, there's nothing to stop it being loaded with flechette or shot cartridges rather than airburst rounds, which would offer devastating in-your-face firepower. (There are some international legal issues around soldiers using shot rounds against enemy troops, but they wouldn't apply against most of today's enemies. The modern opposition aren't usually national troops, and even if they are the enemy nation hasn't usually ratified the relevant conventions. Shotguns are legally fine for police use, of course.)
Plenty of special forces operators, regular troops and SWAT cops are already happy to carry 12-bore shotguns of various kinds into firefights, after all - they'd presumably be happier yet with an even more brutal, approximately 4- or 5-bore*** weapon holding at least as many rounds. This would be the more so as the Army plans to offer door-breaching 25mm rounds, and shaped-charge impact warheads which could blow a hole in quite thick armour.