Army Ships Precision Guidance Kits to Artillery Units in Afghanistan


U.S. Army artillery units in Afghanistan now have a screw-on fuze that converts standard 155mm howitzer rounds into precision-guided indirect firepower.

The Army recently fielded the XM1156 Precision Guidance Kit, or PGK, to A and B batteries of the 2nd Battalion, 15th Field Artillery Regiment in Regional Command East.

PGK allows for more precise artillery and for fewer civilian casualties on the battlefield. The field artillery has already proven the effectiveness of expensive “smart” munitions such as the Excalibur round. Now they have a cheaper alternative, which still provides the same effective results, according to an Army press release.

“By using the PGK, fire supporters can support the maneuver commander with a more lethal and accurate form of fires,” Sgt. 1st Class Cameron Neal, the battalion fire support noncommissioned officer for 2nd Battalion, 14th Infantry Regiment, said in the release. “By being more accurate, we can reinforce the maneuver commander’s confidence in his fires, allowing us to be relevant in the current fight.”

The PGK allows field artillerymen to attach a precision guidance capability to the projectiles used in the M109A6 Paladin and M777A2 Lightweight 155mm Howitzer weapons systems.

The system is compatible with two standard artillery rounds, including the M795 High Explosive and M549/A1 Rocket Assisted Projectile.

The PGK system uses built-in software, a Global Positioning System receiver, and small “canards,” or aerodynamic fins, to provide more accuracy to the round’s trajectory. As the round follows its ballistic trajectory, the GPS receiver provides the round’s current location and flight pattern.

The system compares that data to the target’s coordinates. With this “should hit” versus “will hit” data, the fins rotate to make small corrections to the ballistic trajectory that ultimately guide the projectile on a more accurate path.

Spc. Evan Clayton, an advanced field artillery tactical data system operator with 1st Platoon, Battery B, said the difference in accuracy between rounds fired with conventional fuzes and those fired with PGK were noticed immediately.

“Our rounds are always on target, that’s something we pride ourselves on as a platoon,” he said. “But watching the PGK’s impact on top of each other, round after round, was definitely impressive. The accuracy was definitely noticeable.”

The 15th Field Artillery Regiment is not the first unit to receive the PGK. Training on the equipment actually began in Afghanistan in March. Initial fielding of the system will be complete by the end of June.

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Matt Cox
Matthew Cox is a reporter at He can be reached at
  • NavyGuy2007

    Interesting! Now that’s creative, never would have thought you could to that to a ballistic round!

  • d. kellogg

    The intention from this program’s onset was that it would allow less ammo (weight reduction) to be carried by the FCS artillery platform, as fewer rounds would be needed to neutralize a target (area effect becoming passe and precision fires on point targets becoming preferred).

    It is, or at least was, envisioned to be adaptable to both the 155 and 105mm artillery in US (and surely eventually our allies’) inventory.

    There is even an offshoot called APMI, Advanced Precision Mortar Initiative, that ports over to 120mm mortar rounds.

    Personally, I would like to see the effort expanded to be compatible with 127mm naval ammo, although the demands of the fuzing system would considerably lessen a given gun turret’s rate of fire (but thern again, the precision means massed bombardment isn’t needed).

    • majr0d

      Excaliber was part of FCS not PGK. (I worked on FCS and was responsible for many of the simulations for the Infantry school to determine FCS’ potential effectiveness)


    JDAMs for the M777. Hmm. That could do some damage.

    • scott

      i think yes

  • FormerDirtDart

    While this system doesn’t have the vastly reduced CEP of the Excaliber, it certainly tightens the shot group of standard rounds.

    • wpnexp

      Especially out to extended ranges, where to round has more time to drift off course, and is more likely to be affected by winds. With this system, the artillery really needs to start extending the range of its cannons, to be able to attack more targets. We also need to be able to endanger enemy artillery with more than the GMLRS.

  • Prodozul

    Can’t help but think of the Looney Toon’s when looking at this…

  • drone

    Not to diminish the achievement but surely they could make it a bit more aerodynamic, surely that shape must cut down maximum range considerably

    • d. kellogg

      Bear in mind this is only an early iteration.
      Just as with Excalibur (M982), they aren’t going to stop just at this design, but refine it further as the technology matures.
      As to causing range reductions, I’d anticipate that, like Excalibur, they will refine the aerodynamics and control algorithms to allow it to adjust its trajectory into a modified glide slope and slightly improve range, eventually.

    • FormerDirtDart

      What you are referring to as a non-aerodynamic shape is a plastic covering that provides environmental protection and linkage when setting the fuse. It is removed just prior to loading.
      I direct you specifically to slide #4

      • drone

        Ahhhh… I hadn’t seen it in the buff! Thanks for clearing that up :)

      • Ronnie

        At last a Lonny Gunner who knows…. what’s on and what’s not on, who does what and who’s up who and who has paid.
        Armchair civvies. LOL

        • Stan

          As someone fully engaged in the civvy experience I resent your mischaracterization. I limit my armchair theorycrafting to military and space exploration.

      • wpnexp

        Excellent site, thanks for the post.

  • Leeretarmy

    That must be some impressive software to guide a spin stabilized round not sure of the RPM’s Rotations per minute and arty round has but it must be up there.

    • EW3

      You raise an important point.

      I’d think it can be used only with smoothbore artillery.
      The RPMs would make the GPS have a lousy fix and not sure how the forward mounted fins could handle the rotation.

    • EW3

      Just realized that the tracking unit is not rotationally connected to the shell.
      The shell spins but the traking unit is stationary.

  • oblatt1

    This is just manufacture PR, 90% of the time in Afghanistan we are firing at empty space, this is just a system for an expensive precision miss

  • Guest

    The troops are also getting better bullets:

    I wanted to send this to this site’s tip page:

    but it only allows one submission per user.

    Is there a way to send additional tips/links?

    • FormerDirtDart

      I believe that ammo was initially introduced in theater in like the late summer/fall of 2010.

  • DonM

    With greater precision, there is an opportunity for similar lethality overmatch with a smaller caliber. A standard caliber for Mortar, Artillery, Tanks main cannon, and air defense rounds would permit each platform to perform multiple missions, reducing the need to reorganize and cross attach between missions

    • Weber

      That’s a good idea but we use the different size ammo for different missions. I was a marine cannon crewman with the M777, conventionally the 155mm is for targets like armor formations, large troop concentrations, and fixed fortified enemy positions. Mortars are for squad/platoon level targets, light armored vehicles, and light enemy positions. Tanks obviously go tank on tank and infantry support, and we use missles for air defense only. Depending on the situation its sometimes faster just to call in an airstrike as opposed to calling in arty since those rounds might malfunction and not land where you want them to

  • SFP

    While this system doesn’t have the vastly reduced CEP of the Excaliber, it certainly tightens the shot group of standard rounds.