The 15.6 kg (34.5 pound) Griffin had earlier entered service in Afghanistan aboard UAVs. The older Hellfire II weighs 48.2 kg (106 pounds), carries a 9 kg (20 pound) warhead, and has a range of 8,000 meters. The Griffin has a 5.9 kg (13 pound) warhead which is larger, in proportion to its size, than the one carried by the heavier Hellfire. Griffin has pop-out wings, allowing it to glide and thus has a longer range (15 kilometers) than Hellfire. UAVs can carry more of the smaller missiles, typically two of them in place of one Hellfire.
This use of missiles instead of cannon has allowed for a major change in how gunships are used. As a result, in 2011 SOCOM, for the first time since the Vietnam War, allowed its MC-130 gunships to operate in daytime. For the last 4 decades it was believed too dangerous for these low, slow flying, heavily aircraft to operate when the sun was up. The key to this change is the use of missiles by gunships. The new, small, missiles enable the slow, large, MC-130s to operate above the range of ground fire and still hit their targets.
Dragon Spear is based on the earlier Harvest Hawk system, which enabled marine KC-130J tankers to be transformed into a gunship with the addition of the portable weapons and sensors. The marines had long noted the success of the U.S. Air Force AC-130 gunships that SOCOM (Special Operations Command) uses. But they couldn't afford them, as an AC-130 costs more than three times as much as a marine KC-130J aerial refueling aircraft. But the marines developed a solution. This is something the marines often do.
The KC-130J is the latest, and largest, USMC version of the C-130 transport used for aerial refueling. The KC-130J can also carry cargo and weapons (bombs and missiles) hung from the wings. Thus the Harvest Hawk version of the KC-130J adds a targeting pod, with the data going to a special cargo container containing control equipment (computers, commo, and displays) enabling operators use of the day/night sensors of the targeting pod, to fire missiles hung from the wings. The SOCOM version is the MC-130W.
The original plan was to have a 30mm Bushmaster cannon fired out the door, so that there would be gunfire support as well. But this was made optional, as the 14 missiles seemed to provide sufficient firepower. It also means less for Harvest Hawk to carry. The Mk44 30mm Bushmaster cannon weighs 157 kg (344 pounds) and fires at 200 or 400 rounds per minute (up to 7 per second). The cannon has 160 rounds available, before needing a reload. That means the gunner has 25-50 seconds worth of ammo, depending on rate of fire used. Each 30mm round weighs about 714 g (25 ounces, depending on type). Explosive anti-personnel rounds are fired when used in gunships. The fire control system, and night vision sensors, enable the 30mm gunners to accurately hit targets with high explosive shells. Existing SOCOM AC-130 gunships are armed with a 105mm howitzer, a 25mm and 40mm automatic cannon. But the two smaller caliber guns are being phased out of military service. The air force is considering equipping its gunships just with smart bombs and missiles.
The big thing with gunships is their sensors, not their weapons. Operating at night, the gunships can see what is going on below, in great detail. Using onboard weapons, gunships can immediately engage targets. But with the appearance of smart bombs (GPS and laser guided), aerial weapons are more available to hit any target that is found. So Harvest Hawk would be able to hit targets that were "time sensitive" (had to be hit before they got away) but could also call on smart bombs or laser guided missiles for targets that weren't going anywhere right away. Most of what Harvest Hawk does in Afghanistan is look for roadside bombs, or the guys who plant them. These the marines want to track back to their base and then take out an entire roadside bomb operation.
Ultimately, the air force and SOCOM see the potential for the Harvest Hawk/Dragon Spear approach replacing custom built AC-130 gunships. There would still be a need for specially trained gunship crews. But they, and the several cargo containers of Harvest Hawk gear, could be held ready to go wherever they are most needed. SOCOM used their version of Harvest Hawk (the Precision Strike Package) in their MC-130 transports (which are already equipped for all-weather operations). Meanwhile, SOCOM is expanding its existing AC-130 gunship fleet to 33, with the acquisition of 16 new AC-130J models. But the big change for gunships is the switch from automatic cannon (20mm, 30mm, and 40mm) to missiles. The cannon requires the gunships to fly low, within range of heavy machine-guns and portable anti-aircraft missiles. Missiles can be fired from much higher and new sensors still enable the gunship crew to get an up-close view of what is down there.