Original URL: http://www.theregister.co.uk/2009/05/27/xm_25_summer_field_trials/

Summer debut for Judge Dredd computer smart-rifle

Exploding wireless mini-shell ammo hits round corners

By Lewis Page

Posted in Science, 27th May 2009 14:11 GMT

US Army officials have announced that the high-tech XM-25 computer smartgun, intended to let soldiers shoot at and hit enemies hiding around corners, will enter field trials this summer. The "counter defilade" gun, similar in size to existing infantry weapons, is expected to reduce the number of controversial airstrikes used in Afghanistan and Iraq.

An XM-25 being demo'd. Credit: PEO Soldier.

Your trench has become your grave.

Regular Reg readers will already be familiar with the XM-25 and its unique ability to strike at enemy gunmen or snipers who are protected by roof edges, corners, rock outcrops, trenches etc. This is accomplished by using a laser rangefinder to precisely measure the distance to the enemy's protection (for instance a low wall). The XM-25 smartgunner then selects how much nearer or further from that location he thinks the target is - for an enemy behind a normal wall, the soldier would choose +1 metre. If the soldier had lased the back of a room or cave through an opening, he might choose -1 or -2 metres.

Then the XM-25's computer calculates the exact angle the weapon's barrel should be elevated to in order to lob a 25mm explosive mini-shell through the selected point in space, and generates a new pipper in the gunsight accordingly. The soldier moves the pip onto his or her original point of aim, so adjusting the gunbarrel to the correct angle.

The shell in the XM-25's breech gets its electronic time fuse precisely set by a wireless transmission from the smartgun computer at the instant it is fired. It flies out on the calculated ballistic arc and explodes exactly in the chosen spot - above the head of an enemy in a trench or on a rooftop, right next to one lurking around a corner, dead in the middle of a room etc. The miniature explosive warhead sprays the target(s) with shrapnel.

Rich Audette, the US Army official in charge of the XM-25, described the weapon's usefulness in a briefing last week.

"In Iraq we had many instances where there was a sniper firing from a rooftop and you have a squad trying to engage that target, but the soldiers couldn’t get to him with the weapons they had, so they’d call in the Air Force to drop a JDAM [joint direct attack munition - a smart bomb],” he said. “We can take out the target at $25 per XM round as opposed to a $20,000 to $50,000 JDAM.”

Quite apart from saving money, less smartbombs dropped would also be a good thing in terms of winning the propaganda war - particularly in Afghanistan at the moment, where US and allied airstrikes are believed to be killing large numbers of innocent civilians.

Judge Dredd style array of ammo types seems to call for voice selection

The XM-25 is said by Audette and his team to weigh no more than a normal M-16 rifle with attached underbarrel grenade launcher. It's not much longer than the standard M-4 carbine.

On the down side, the current iteration of the XM-25 holds only five 25mm smartshells. Some would say that a smartgunner would be at a disadvantage in a close-up urban dustup, needing to reload too often.

Audette, however, says that combat ranges in Afghanistan - the new focus for the British and US forces - tend to be longer than those of Iraq's largely urban battlefields. He points out the XM-25's long effective range is 750m, more than twice that of existing 40mm thud-gun grenade launchers and a good bit more than the M-16 and M-4.

XM-25 in digi-cam. Credit: PEO Soldier.

Sadly the chameleon video-camouflage coating still suffers from pixellation at times.

Furthermore, the latest Army fact sheet (pdf) on the XM-25 hints at an enhanced range of ammunition in future. Baton rounds, door breachers, flash-bang stun warheads and armour-piercing (presumably mini-shaped-charge) shells are all planned. There's also an "anti personnel" round: in the US military that normally means an artillery shell which throws a cloud of smaller projectiles - either metal balls ("canister") or finned darts ("flechette" or "beehive"). The XM-25 version could function like a shotgun, simply throwing the shot or flechettes out of the end of the barrel for maximum closeup firepower, or it could use the gun's airburst capability and deliver a spread of projectiles at long range.

This Judge Dredd-like array of ammo options, combined with the XM-25's other abilities, would seem to suggest that the smartgunner might not feel too disadvantaged among his team mates with their various specialist weapons - squad-auto machine guns, marksman or sniper rifles, combat shotguns and so on. Though it might be nice if there was some handy way to switch ammo types on the fly, rather than changing magazines every time. A selector dial on the weapon, as favoured by the Judge in 2000AD*, might be more practical than the voice selection seen in the movie version.

According to the US Army, these questions will be settled in "field testing this summer", though it isn't revealed exactly where. Previous hints have suggested Iraq as the inaugural theatre, but Audette now seems to be favouring Afghanistan. ®

Bootnote

* Though Dredd still invariably felt it necessary to shout out what kind of ammunition he was using, even if it was quite a mouthful ("steel-tipped high penetration!")