As RF likes to point out, I have a bit of a thing for grenade launchers. I can’t rationalize it or find a practical use — there’s just something amazingly fun about firing gigantic projectiles at distant targets. Especially when those projectiles emit a small orange puff of smoke upon impact. So its no wonder that I absolutely had to try out H&K’s grenade launchers and report back . . .

Let’s start with the old solution for weapon mounted grenade launchers and see how well H&K stacks up.

The M203 has been the gold standard for grenade launchers since 1969. The relatively simple design makes for easy operation and the relatively slender profile keeps the weapon light and slim. Well, as light and slim as a weapon with a grenade launcher can be. But the M203 has some problems.

First, the old girl has a size issue. The standard cartridge for man-portable grenade launchers is a small “low velocity” grenade with a relatively light kick. The reason is the lighter recoil puts less strain on the weapon and the soldier firing it. But these grenades have very limited range, and take ages to get to the target.

So troops in combat asked for something with a little more distance and the medium velocity grenade was born. Unfortunately, the new rounds are too long to fit in the M203’s forward sliding breech, as it doesn’t slide quite far enough to fit.

The second issue is with the trigger. The M203 uses a single action trigger that is cocked when the tube is opened (or so I’m told), meaning a light strike on a primer cannot be easily remedied with a follow-up tap. And the ammunition had a tendency to roll out of the gun when trying to do a grenadier’s TAP-RACK-BANG on the thing.

Issue #3 is the distinct lack of a safety. Unlike RF, I like manual safeties. And the M203 had none. Which, considering the payload, makes me a little uneasy to think about the possibilities there.

Enter the H&K M320 grenade launcher, the U.S. Army’s chosen replacement for the aging M203.

H&K’s grenade launchers, like everything else they make, are over-engineered and highly stylized. But there are three important differences between her and the M203 that make her technically superior.

Number one on the list is the side pivoting barrel. Instead of making the shooter move the barrel up to eject the spent casings and load new rounds, the barrel pops to one side (shown at top). This not only allows the launcher to be more compact and easier to load in tight situations, but it allows the launcher to take the longer medium velocity rounds as well. The release for the swinging barrel is located on the underside of the launcher in the form of a trigger-like button just forward of the actual trigger.

This makes me slightly nervous. Having a second trigger within the trigger guard itself is, as Joe Grine would put it, “not grunt proof.” The manual of arms says to put the launcher on safe before opening the barrel for just this reason, but you know damn well some idiot is going to do it anyway. What concerns me is what happens if that grunt is opening the barrel to remove a live round. With the launcher pointed at his foot. Doesn’t sound like a pleasant experience. Yes you do need to physically move your hand off the fire controls to access the release, but I can just see it happening anyway.

Distinction #2 is the appearance of a grip on the grenade launcher itself. The M203 used the magazine of the rifle as a forward grip for the grenade launcher, but the M320 has its own built into the firearm.

When using the launcher in a standalone mode, that grip is perfect. It provides something to grab onto and is at exactly the right angle to be comfortable. On the rifle it seems somewhat redundant, seeing as the magazine grip works well enough to justify not having the extra weight added to the launcher. Rifles are heavy enough as they are, and the grip really isn’t helping. The trigger mechanism could have been adjusted to use the magazine just like the old model.

Which brings me to another question: why do we need another vertical forward grip on this thing? I can understand if on the standalone version you want something like that, but on the rifle its just more weight for something the rifleman doesn’t use. And even in standalone mode its not really a required piece of equipment, as you could just hold the barrel.

So, from a design standpoint its a mixed bag in my opinion. Better trigger, better loading mechanism and better safety, but perhaps a bit too heavy to lug around a battlefield. Heck, I complain when I have to carry my AR-15 more than 100 yards.

But how does it feel to fire the thing?

The trigger is LOOOOOOOOOONG, but ultimately satisfying. Recoil is minimal, and the gun seems damned accurate. Everything you could want from a grenade launcher.

H&K M320 Grenade Launcher

Caliber: 40mm Low / Medium
Barrel: 11″
Size: 13.7″ with stock extended
Weight: 3.3 lbs
Operation: Single Shot Double Action
Finish: Black
Capacity: 1 round
MSRP: $??? (LE/Mil Sales Only)

Ratings (Out of Five Stars)
All ratings are relative compared to the other weapons in the gun’s category.

Accuracy: * * * * *
Dead accurate at 250 yards, 3 rounds in a row.

Ergonomics: * * * *
The ergonomics are definitely better than the old M203, but weight is still an issue.

Ergonomics Firing: * * * *
The only issue I have here is with the weight of the thing. It makes the rifle a little hard to keep steady. Also, the trigger is MASSIVELY heavy to pull.

Reliability: N/A
I didn’t have enough time to test the reliability, but the design seems solid.

Overall Rating: * * * *
As a standalone system its great, but on a rifle there are some redundancies that could be eliminated to save weight.


  1. There are 203-versions with a safety as well, at least in other armed forces.
    Also, apart from increased explosive payloads newer star shells and smokes are also longer than can be accomodated in the 203.

  2. I’ll concur with Lew, all the M203s I’ve fired in the US Army had a “flap” safety in the trigger guard. Thanks for the article.

  3. I carried a 203 for many years and never had a problem with it other than the weapon being too front-heavy. Other than the issue of med-velocity sized rounds, it seems like asolution looking for a probelm. I’m sure whoever makes the 203 could engineer something to accomodate longer rounds. Oh, and every 203 I was issued had a safety that worked very well.

    If you really wanted to help our grunts out, make lighter weapons and ammunition. Most of the time I felt like a pack mule.

    • How much lighter weapon/ammo do you want. Already down to a barely lethal rifle/ammo, then use it for a tool rack. How about a C02 powered BB rifle and a plastic bottle of BBs, would that be light enough? Lose that body armor and run faster, that would help too. Get rid of the iPad. Get out of that glorified armored pick up and walk awhile, may get in shape. We humped M-14s plus gear, motar plates/tubes /rounds/ammo, whatever we might need, thru jungle, up hill/down hill, thru swamps, in 100+ heat, freezing rain. And paratroopers are not known for their physical size. I am sorry, I can not feel much sympathy for you and that “heavy” rifle and ammo.

      • My dad was in the 11th AB and carried a tommy gun as well as a mortar at times. Along with all the other gear (including a bottle of scothc I am told.) He was 5’3″ and 135lbs.

      • Not to trivialize the realities of combat in Vietnam, but it seems to me that the modern warfighter is expected to carry more weight than previous generations of warfighters.

        First of all, your comparison of an M16+M203 to an M14: As the poster above said, the M203 makes the rifle front-heavy; this means that while a loaded M16+M203 combo (around 12 pounds) isn’t much heavier than a loaded M14 (About 11.5 pounds), the end product is a rifle that isn’t well balanced. This means it isn’t as maneuverable, and it *feels* heavier due to the distribution of weight.

        Then there’s armor. Do you have ANY idea how much SAPI plates weigh? You’re looking at about 30 pounds worth of ceramic plates (10 front, 10 back, 5 per side), and almost certainly some degree of kevlar on top of that for additional protection. I wouldn’t be surprised if the full compliment of issued/issuable armor weighs over 50 pounds per man.

        Then there’s ammo, rations, water, etc, etc, etc.

        Oh, and they’re tramping all over Afghanistan and Iraq, and while it may not be as humid as Vietnam, it’s at least as hot during daylight hours. So, figure that they’re lugging about the same weight gear-wise, PLUS 30+ pounds of armor, all in a desert environment.

        TLDR: Sherman’s observation that “War is Hell” is still applicable.

      • Sorry, I am late to the party:

        In the photographs and movies taken of the WWII and Vietnam Airborne or Ranger soldiers climbing into transport; each soldier carried all he could manage to walk with.

        Yes, every ounce counts. However, to soldiers going into battle, every round and piece of equipment mattered far more.

        When the Rangers assaulted their second beach in WWII, having learned lessons from their first rather easy amphibious landing; every one of them carried as much extra ammo and munitions that they could.
        All they had to so was get the ammunition above the tide line and drop it. Then they could fight unencumbered, yet have access to ammunition, mortars and grenade when needed.

        Neither the Airborne or the Rangers carried extra food. If they had space, they carried ammunition, munitions and gear.
        During D-Day, the Airborne troops stuffed their extra duffels with weapons, munitions and ammunition. They were led to believe that they could parachute in with this extra weight hanging from a long cord. The duffels were supposed to land first allowing the parachutist to land and roll.
        Only the majority of the duffels were so heavy that when they were dropped, they snapped the connecting cord. Those that were not lost at the jump dragged down the soldier very fast causing more injuries.

        Yes, the modern soldier is weighed down with armor and communication gear.
        What weapon developers should take into account is how a soldier will carry, deploy, aim and use their weapon. There should not be any negative compromises that affect a soldiers basic needs.

        Fielding an awkward weapon is counter intuitive though.

  4. Okay, so I really do not paint a great picture of the LAW player’s life and generally speaking it is not easy to effectively use a LAW without getting taken out quickly shortly thereafter. While I have seen some LAWs that address some of these issues, including one LAW that was only slightly larger than a pistol, almost every single one has the drawback of the player using it no longer having the ability to fire his marker while doing so. With that in mind many players have turned to their airsoft brethren and started adapting airsoft M203 grenade launchers for use as rocket launchers.

  5. good review, but all i could focus on was the “model’s” hands. if that is line grunt, i turn in my peanut gallery ID card. his hands & fingernails are so manicured, has he ever done hard work? Figured if you could call a GRENADE Launcher a gun, i could expand too! keep up the good work………….

  6. I’ve played with both, most recently at JRTC at Fort Polk. The M320 seems to some extent a solution in search of a problem; our 203s all had the aforementioned “flap” safeties (think the safety on the M1 Garand) so that’s kind of a non-issue, the M320 is heavier (from what I could tell on direct comparison) and much bulkier with the unnecessary folding foregrip, and the DA trigger is straight garbage.

    On the plus side: the selector-switch safety is a nice touch. No experience with the longer grenades, so I can’t comment on that. But the biggest advantage I could identify was… it says “HK.” Worth it?

  7. From what I recall, you CAN chamber a med or possibly even a high velocity 40mm grenade in a 203. But firing it would be disastrous. I may be mixed up here, though: I had basic training with a 203, but never carried one, because, frankly, I couldn’t hit the broad side of a barn with one, and I already had a fuckload of other stuff to carry, including a SMAW.

    I have never seen a 203 with out a safety, either…

  8. This was my go to weapon when I was in Afghanistan. I loved shooting it and many times carried my M4 on my back and just walked around with it as my primary. We used ours as standalone weapons as when they are mounted to the M4 it basically makes both weapons way to difficult to handle and use effectively.

    Rumor has it that they cost around 8k, as least that is what my armorer told me our battalion paid for each one (keep in mind that we also got a laser range finder and a day/night sight)

  9. I loved the M79. On slicks it provided a means for a gunner to place CS gas or HE into caves from the air. It wasn’t bad for smoke placement, either. Boy am I glad I was in Aviation, after reading complaints about humping big loads.

  10. I’m probably in the minority here but I’ve always questioned the usefulness of any 40mm. Just not enough lethality to be a solid standalone and too cumbersome as an underbarrel mounted device. Never got stuck carrying one, I was a saw b1tch most of my time.

  11. Reading this post I couldn’t help thinking of Inception.

    “You mustn’t be afraid to dream a little bigger, darling.”

  12. Reading all this, I can’t help but be envious since the M79 I humped around with was not exactly “sleek”. But she was reliable and and great for shaking the leaves in an ambush

  13. I carried one/and jumped with it in the Canal zone,Ft Kobe.I was never really enamored of the thing didnt handle like a rifle nor was it a dedicated GL like the M79.Awkward to say the least and the sights also difficult to use(It DID have a safety that blocked the trigger IIRC) .But if carefully fired adequately accurate and no doub t effective enough fired thru a window @>hundred meters and lay one in the middle of a 5 meter radius @ max range. But,I fail to see any advantage to replacing the M203 with an overengineered 8k replacement.Its still just a 40mm GL.
    US procurement wont spend our tax $ on a 2-6k wpn sight on a LAW I hope?

  14. As far as literally shooting yourself in the foot goes, it would probably hurt like hell but as likely as not the grenade wouldn’t go off. The spinning of the grenade doesn’t arm the projectile until it is 8-10 feet downrange. If you got it just far enough downrange to arm the round before it impacted something, you’d be in a world of hurt well inside the 5 meter lethality range.

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