Half-Life: Alyx

Half-Life: Alyx (2020)

Half-Life: Alyx is a 2020 virtual reality first-person shooter developed and published by Valve Software. The highly anticipated continuation of the acclaimed Half-Life series, Half-Life: Alyx was designed to be the flagship title for Valve's own VR headset, the Index.

Set five years before the events of Half-Life 2, players control 19-year-old Alyx Vance, a member of the fledging resistance force against the interdimensional Combine Empire that have occupied Earth. Operating in City 17 somewhere in Eastern Europe, Alyx and her allies discover that the Combine are hiding something mysterious and very powerful within the city, sending Alyx on a journey to find a weapon that could tip the scales in the battle for Earth.

The following weapons appear in the video game Half-Life: Alyx:

Para-Ordnance LDA

A modified Para-Ordnance LDA appears as the first firearm obtainable; due to the nature of the game, it has no direct name, though the weapon's markings indicate that the pistol is a "Le Clarion" (French for "The Bugle") maufactured by "Gantrty Mfg. Co." as part of "Series AA Europa". By default, it is fitted with a muzzle brake, as well as a set of aftermarket illuminated sights, and grips similar to those of a Kimber Warrior with an electronic ammo counter in the left panel. The LDA has four upgrades (a reflex sight, a conversion from semi-auto to a selectable 3-round burst mode, a "bullet reservoir" that doubles the capacity from 10 rounds to 20 with a strange device that pulls rounds out of the ejection port, and a laser sight); these upgrades ultimately make it resemble (and, lore-wise, presumably making it into) Alyx Vance's pistol from Half-Life 2. One of the bonuses included with a pre-order of Alyx was a set of alternate weapon skins; the LDA's consisted of a blued finish with wooden grips.

Para-Ordnance P14.45 LDA - .45 ACP

"You're gonna need a gun! Don't worry, it's unloaded."
"It's unloaded now!"
The LDA's first shot comes not at the hands of the player, but the pistol itself; having apparently forgotten to check the chamber, Russell's throw somehow sets the gun off (possibly due to its modifications, since nearly all factory-stock 1911 derivatives are drop-safe). Interestingly, the effects here are rather out-of-sync; the slide locks back before it goes off (never mind that most handguns don't lock back without an empty magazine inserted anyway), and the windshield breaks a couple frames later (made even stranger by the fact that the gun isn't even pointing at it). Suffice it to say, the pacing of the scene makes these details rather hard to notice in-game.

Alyx loading a double stack magazine into her pistol.

Right side view of the gun after releasing the slide.

Attempting to leave Russell's yard, Alyx immediately runs into an obstacle, and decides to take aim at it; the notch-and-post illuminated irons are an interesting choice, compared to the quasi-standard 3-dot setup most video game handguns feature.

"Oh. You, uh, took care of that lock, then. Good. Great.

...DID have the key for it. But, should've given you that. That, that's on me."

Just outside the Quarantine Zone, Alyx looks over one of the LDA's magazines. Despite having a deeper base than standard 14-round LDA mags, these only hold 10 rounds of .45 ACP (all of which are jacketed flat-points with glowing blue bands around their cases, to make them more visible); presumably, the extra space houses the electronics for the round counter and lights. Oddly, despite how common these mags are in-game (with numerous Combine personnel carrying them, and several being stashed in various places), nobody but Alyx ever uses them for anything.

The LDA's cheapest upgrade consists of a reflex sight (which appears to be some sort of two-part hologram projector); this is mounted on a rather large sheet-metal bracket attached to the frame, which seems to partially block the muzzle brake (which at least lines up with how the Combine tend to build things).

Looking through the sight at a zombie; aside from giving the player a nice, clear yellow dot to aim with, the reflex sight also highlights enemy weakpoints and other notable targets - in this case, both the headcrab on the zombie's head (the enemy's weakest point) and the explosive gas container next to it are highlighted.

Having acquired the second available upgrade, Alyx tries out the slide-mounted fire selector switch; note that the switch's animation is a bit delayed, so it shifts mode a few frames after she actually hits it. The burst upgrade's slide-shroud also covers up the rear sight, so it's moved to the top of said shroud; this would be shown in a screencap of its own, but the sight picture is more or less the same, and the mounting for the reflex sight blocks it anyway.

Exploring the sewers of the Quarantine Zone, Alyx comes across a crate; these appear in various areas of the game, and (as the logistically terrifying text on the top implies) contain various useful items, including ammunition, grenades, and healing syringes full of mildly-concerning bright green fluid. The markings on the side are a bit more specific, claiming that it contains 5.45x39mm ammunition; this is one thing they never do contain in-game, since the game lacks any firearm which could use it.

Unlike Gordon, Alyx doesn't have an appropriate tool for opening crates, and thus has to make do with her LDA; she gets a magazine and a bunch of packing peanuts for her troubles. Her trigger discipline remains consistently nonexistent throughout the game, though this could be explained by her lack of formal training.

Performing a brass check; this can be done, though the abundance of ammo counters renders it a bit pointless. This is presumably why the chambered round sits in one place, rather than moving with the slide.

If that wasn't sufficient to stifle your brass-checking impulses, don't forget that being a bit overzealous with the action can result in this.

The ejected round can be picked back up, though given its incompatibility with the Gravity Gloves, the manner in which it clips through Alyx's hand, and the fact that nothing can actually be done with it, it appears that the player was never meant to try this. To save on screencaps, this shot also shows Alyx ejecting a now-empty magazine.

Firing a burst at a zombie; note that the back of the selector now shows 3 red dots instead of one white one, indicating that it is in burst mode (its upper position).

Purchasing the "bullet reservoir" upgrade adds two things to the pistol: an extra ammo counter on the left grip panel, just above the regular one...

...and, more significantly, a large, bulbous block attached to the right side of the frame that holds 10 extra rounds. And, of course, its own independent ammo counter.

Midway through a gunfight in an abandoned subway station, Alyx shoves a new magazine into her fully-emptied LDA, and watches as the reservoir steals all of its ammo. This is achieved through a couple of insect leg-esque arms (which the Combine seem awfully fond of) that reach into the ejection port and yank rounds out (a process which, going frame-by-frame, seems to take rounds from the magazine to the reservoir without them crossing the space between); when the magazine runs empty, it then manually places them straight into the ejection port to keep the gun fed. The reservoir also apparently has some means of manipulating the slide, since inserting a full mag with a partially-filled reservoir will lock the slide open to reload the reservoir, then drop it when the process is finished (not to mention its ability to forcibly release the slide with an empty magazine inserted); oddly, despite this, it refuses to release the slide when it's already locked open, leaving Alyx to do it herself.

Alyx somewyhat oddly grasping a bundle of 4 magazines bound together with tape; exactly one of these is found in the entire game. None of these can be used in this state; Alyx's backpack apparently eats the tape, and she will instead pull out 4 full, unaltered magazines. Said tape also apparently prevents the ammo counters from working correctly, since they read "0"; truly a strange object, all in all.

With the addition of its most expensive upgrade (a laser sight), the LDA reaches its final form. This also prompts the last portion of a Ship of Theseus-esque discussion Alyx and Russell have over whose gun it really is (with more discussion occurring every time she gets an upgrade for it); since seemingly more or less none of the original parts are replaced, this is presumably instead based on whose components make up more of the overall gun.

Note that, contrary to what this section may imply, weapon upgrades do not have to be acquired in any particular order; the "first" upgrade is simply the cheapest (and the first one in the list), and the shots were simply arranged as such to create a sense of progress across a continuous journey through the game. To completely destroy that sense of linear progression, here's a shot of the LDA with nothing but the laser upgrade, in an earlier section of the game than the one above.

Aside from ruining your fun, this set of shots also serves to show off the laser upgrade in better detail. Note that, despite the rather bulky underbarrel device clearly being designed as a laser sight, the actual laser beam emanates from the end of the guide rod; while such guide-rod laser sights do exist in reality, they generally require the guide rod plug to not be a solid chunk of metal. And yes, the large sheet-metal bracket on the front of the frame is equipped automatically with any upgrade, not just the reflex sight.

Realizing that this section's overstayed its welcome a bit, Alyx decides to merge a few different observations into one screencap; aside from showing what the end of the laser beam looks like, this also shows off two of the other ways the game alerts the player that the LDA is empty (in addition to the ammo counter on the grip, the slide locking back, and a small tone that sounds when it does so): the pistol's magazines all have bright orange followers (a feature of many real-life magazines, meant to make a locked-empty pistol more obviously distinct from a loaded or jammed one at a glance), and the bottom of the slide features a bright red LED that shines onto the user's hand when it locks back (a feature real-world manufacturers have understandably been a bit hesitant to try).

Generic Revolver

A sign seen at the beginning of Chapter 4 displays several items that are prohibited on the now-abandoned subway system, with a silhouette of a somewhat generic, vaguely S&W-ish revolver among them. It should be noted that signs explictly forbidding firearms are seldom seen in European metro systems.

Alyx examines the sign, for once thankful that the game doesn't have any usable revolvers.

"RATEL" Shotgun

The second weapon Alyx can acquire, the game's shotgun is a fictitious design vaguely reminiscent of the Techno Arms MAG-7, with an AK-esque receiver and a Franchi SPAS-12-esque barrel, magazine tube, and set of iron sights. It is semi-automatic, with a capacity of 6+1 12-gauge shells; it is reloaded by breaking open the receiver and loading shells directly into the magazine tube, in a manner possibly inspired by the Cosmi Lusso, albeit with a traditional underbarrel magazine tube instead of one in the stock. It is marked with the logo of the fictitious "RATEL" brand, and features markings implying Combine ownership (which lines up with it being taken from a dead Combine worker); accordingly, Combine Chargers carry a modified version, with a longer barrel and magazine tube, a heat shield, no stock or trigger guard, and a variety of large, bulky modifications to the front end, including what appears to be a drum magazine of some sort.

Like the LDA, the Shotgun features an alternate pre-order bonus skin, in this case a cleaner satin-nickel finish with a textured black pistol grip; also like the LDA, it features 4 optional upgrades - a laser sight (which blocks the irons, and projects a circle that shows the size of the weapon's spread), a "Double Shot" upgrade that gives it a SPAS-12's heat shield and a set of indicator lights, somehow allowing the weapon to fire two shots in rapid succession (in a manner reminiscent of the "fire both barrels" option from the prior games' actual SPAS-12s, though the two rounds are fired neither simultaneously nor in a quick burst - the mechanical delay between the first and second shots is simply cut down to almost nothing), an "Autoloader" that holds 6 extra shells on the side of the weapon, and automatically loads them into the magazine tube whenever it is opened, and a grenade launcher that fires entire hand grenades (somehow converting them from timer-based to impact-based detonation; oddly, though the manner in which they are fired suggests that this is supposed to work like a bullet-trap rifle grenade launcher, firing grenades neither consumes nor requires shotgun shells).

The Ratel/Shotgun as it is initially acquired - straight from the cold, dead, long-fingered hands of a zombified Combine worker that the sewers' resident Vortiguant had hung from the ceiling by his ankle to use as headcrab bait. Unlike the boxes of shotgun shells said worker was carrying, the shotgun itself can't be grabbed with Alyx's Gravity Gloves (or "Russells", if you prefer), so she has to lower the corpse to grab it by hand.

Upon doing so, Alyx will grab the weapon by its receiver with whatever hand she reaches out first; this is unique, since following this...

...the weapon can only be held by the pistol grip, and only with the player's selected "weapon" hand. Note the red area near the muzzle; the charging handle has a red LED on it, which lights up whenever the chamber is empty.

Opening up the shotgun for reloading occurs in two stages: first, Alyx uses her thumb to push the tab-like lever behind the trigger down, causing the AK-safety-esque diagonal component above the trigger to tilt.

Next, a folding armature inside the lower receiver unfolds as the barrel slides forward and the entire upper receiver tips down at the front.

Pausing for a moment to take a look a pair of shells; according to the markings, these are 70mm (2 3/4") 9-pellet 00 buck shells, made by the fictional "Salvotech" company (a brand which is also featured on Half-Life 2's shotgun shell boxes). They're more or less just ordinary 12 gauge shells, barring the addition of a glowing blue ring just above the brass (presumably to make locating them easier).

Remembering that this is (ostensibly) a time-pressured scene, and shoving the shells into the magazine tube; they can be loaded in 1 or 2 at a time, depending on how many are needed and/or available. Here, the hinged armature in the receiver presumably responsible for forcing/holding the shotgun open is clearly visible.

Grabbing the shotgun by the magazine tube and forcing it shut; as the text prompt shows, this can also be achieved by simply swinging your hand upwards, but that doesn't make for a good screencap.

Racking the forward-mounted folding charging handle, and chambering a shell; note what appears to be a Combine ownership mark/serial number on the... slide? Dustcover? Bolt carrier? Not really sure what the precedent is here...

Right around when Alyx figures out how to load the shotgun, several zombies bust through the walls. Better hope you've figured out the irons by that point, too.

Truth be told, it's not strictly necessary - the zombies are close enough for point-shooting to work just fine, and the shotgun isn't effective much further than that anyway.

Ammo pickups for the shotgun come in one of two forms: loose shells, or plastic boxes like this one. These have space for a dozen shells (and no markings), but never contain anything close to that. Still, they're always a welcome sight - even before they can be used, since the first one available (shown here) is obtained before the shotgun itself is.

The cheapest available upgrade for the shotgun, the laser sight; while rather 80s-esque in its size and placement, it is far more advanced in function - rather than simply telling you where the gun is pointed, it also tells you where you can actually score a hit, and where there's no real point in trying.

Exploring a hotel that the Combine made everyone abandon, occupied, abandoned, and then re-occupied, Alyx acquires the "Double Shot" upgrade; this gives it a small indicator on the back of the bolt/slide (in line with the barrel), along with a SPAS-12's heat shield. The latter would make the iron sights more fitting were they not blocked by a laser at the moment.

Alyx puts this to good use during a gunfight in a construction site that the Combine decided to make even more OSHA-unfriendly; cornering a Suppressor, she hits him with the first shot...

...and then the second. About the only way this could really make sense is if the shotgun had some sort of mechanical rate-reducer mechanism (which wouldn't make much sense on a semi-auto), and the upgrade added some sort of additional system that can selectively disable it. One standard cycling delay later, both lights come back on, and the shotgun's ready for another quick double-tap. Unlike the Suppressor.

Upon purchasing the "autoloader" upgrade, Alyx finds herself somewhat dismayed that it only comes half-loaded, and grabs 3 shells from her backpack; this is one of the only times that she'll hold them like this.

She then proceeds to just sorta shove them in there.

A fair bit later in her travels, she puts the device to use; the automatic loading occurs in two stages once the shotgun is broken open: first, yet another insect leg-esque grabber yanks a shell out of the side-mounted rack and rotates it...

...before shoving it into the magazine tube as another component advances the rack's shells back a space, readying another for pickup. Repeat at fever pace until the tube is fully loaded (or all of the rack's shells are gone), then manually close the shotgun, and rack the charging handle if necessary.

The shotgun's most expensive upgrade, the grenade launcher, consists of a sheet-metal bracket on the front, a hinged armature for holding a grenade (one of which comes free with the upgrade), and a red plastic handle resembling a pump-action shotgun's forend.

Grabbing this and pushing it forward raises the grenade up into the path of the barrel; disarming it simply requires removing the grenade, which causes the spring-loaded forend and grenade mount to snap back/down out of the way. If the weapon also has the laser upgrade, it changes from a red cone to a single blue beam.

To be precise, it becomes a curved beam, showing off the precise path a fired grenade will follow; at full size, several flickering horizontal lines in line with this arc can be seen, suggesting that the line is actually a series of laser beams that all somehow stop at various points along the arc.

Launching the grenade; the built-in LED immediately starts up, and the lever flies skyward. Oddly, despite this somehow not using any of the shotgun's ammunition, its action visibly cycles.

The grenade hits its mark; firing grenades from the launcher will convert them from timer-detonated to impact-detonated, presumably for the sake of convenience.

Taking advantage of the uncharacteristic friendliness of a Combine Charger, and getting in for a closer look at his shotgun.

A view of the shotgun's underside; note the large drum, and the diagonal box sticking off it. The function of either of these things is unclear.

See, the unfortunate thing about uncharacteristic behavior is that it tends to be neither common nor permanent.

Luckily, through the magic of console commands, a less tenuous coexistence can be forged.

Notably, while clearly a variant of the same weapon, the Chargers' shotguns are substantially larger than Alyx's in every dimension. In-universe, this could mean that they're a scaled-up version chambered for a larger round (possibly 10 gauge), though from a practical perspective the model was likely just scaled up to make it more visible and imposing.

"Pulse SMG"

The third and final weapon Alyx acquires (aside from hand grenades) is the "Pulse SMG"; it doesn't appear to be based on anything real, and is seemingly meant as a smaller (and earlier) version of the Combine "Pulse Rifle" seen in Half-Life 2. Like that weapon, it is loaded with small "plugs" which each constitute 30 shots' worth of ammunition/power; however, its behavior is somewhere between a conventional firearm and an energy weapon (with sounds and visual effects similar to both), unlike the clearly-meant-as-a-firearm Pulse Rifle. As with HL:A's other weapons, it lacks a stock or forend, and is thus held like a pistol; Combine soldiers, however, hold it by the barrel shroud instead.

The weapon has 3 upgrades: a "Reflex Sight" (which is, like the LDA's, entirely holographic), a laser sight, and an "Extended Magazine"; the latter makes the weapon behave a bit more like its HL2 counterpart, with 3 "plugs" held in reserve (in addition to the one in the "chamber") and loaded automatically when the current one runs dry. Combine-wielded Pulse SMGs all feature this upgrade, though none ever feature any others. Interestingly, this upgrade also adds what appears to be a second barrel below the first; the fact that this component is missing from the extended-magged SMGs used by Combine troops, coupled with the fact that the SMG only has 3 upgrades instead of the other guns' 4, and the fact that HL2's Pulse Rifle had a similar second barrel that fired Dark Energy Orbs, all suggest that a similar launcher was planned as an upgrade for the SMG, but later cut for unknown reasons.

The "Pulse SMG" as it is first encountered (in acquirable form); apparently, the Combine were in such a hurry to re-abandon this building that didn't even have time to do anything with the weapon case they'd just opened. According to Russell, Combine weapons are "bonded" to the user's DNA (or simply to any Combine-recognized DNA, which is unclear) to deter theft; this is also used to explain why Alyx can't simply steal weapons off of dead Combine troops. The fact that they ship said weapons un-bonded, in cases that include ammunition, suggests that they might not have thought this all the way through. Suffice it to say, by HL2 they have clearly abandoned this idea.

Not one to look a gift submachine gun in the mouth, Alyx picks the weapon up and looks it in everything else.

Ammunition for the SMG comes in the form of these energy cells, of which two are included with the weapon. As mentioned, most militaries typically ship weapons and their ammunition in separate crates, for this precise reason.

Deciding to do as the voice in her eyes tells her, Alyx shoves this cartridge into the open, waiting arms of the SMG's... loading port? Magazine well? The terminology for a nonexistent class of weapon is, needless to say, not well-established.

The SMG eagerly accepts its gift, mechanical components moving in all directions as it grabs the "plug" and shoves it into the "chamber".

The entire rest of the cartridge is then simply discarded. It's not at all clear what purpose this section serves; it may be meant to stabilize or preserve the important "plug", though in practical terms it is most likely intended to make SMG ammo more visible and distinctive-looking (as the plugs alone would be small, hard to spot, and could possibly be mistaken for shotgun shells at a glance; this is presumably the same reason why the Pulse Rifle's ammo pickups in HL2 are magazines instead of individual pulse plugs).

Alyx then attempts to aim the weapon at a wall, only to find her efforts stymied by the weapon's total lack of sights.

Grumbling about the Combine and their inability to design a gun properly, Alyx moves forward; conveniently, not 10 feet from where the SMG is acquired are some caged zombies to test it on. For all the flashiness of its visual effects, the practical effects of a shot from the weapon are a bit less than impressive. Well, that's why you get 30 of them - and, thanks to the red ring on the back of the plug, an easy way to tell roughly how many of those 30 you still have.

Another frame of the firing animation; for an energy weapon, it has a conspicuously normal-looking muzzle flash. And what appears to be a reciprocating striker of some sort, which hits the back of the plug each time the weapon is fired.

Alyx's SMG runs dry at a rather inopportune time; the loading port/plug-grabber-thing swings around to the left side as the spent plug is pulled from its glowy orange "chamber" and rather unceremoniously dropped out of the right-side ejection port.

Later, having successfully made the hotel more abandoned than it was already, Alyx takes one last look at the right side of her SMG...

...before covering it completely in the rather massive mounting for the Reflex Sight upgrade, and completely ignoring the HUD.

Aiming through said sight; it features a curiously asymmetric "lens", with an equally asymmetric reticle. All those fancy markings, and they didn't bother putting in a dot at the actual point of aim.

To get an aiming point, you'll need to cough up an extra 25 resin for this little doohickey.

Said doohickey is a bright blue laser sight (which seemingly plugs into the mounting/power supply for the reflex sight); note that, thanks to the magic of bore offset, the laser and the reflex sight don't always "agree".

Given enough distance, however, the two will gradually reconcile their differences. Also visible here are the rather strange mechanics of the reflex sight; while ostensibly some sort of three-dimensional hologram, the sight's body is apparently solid, allowing for this thoroughly impractical party trick.

With its third and final upgrade, the SMG becomes substantially bulkier-looking. Probably doesn't help that it's essentially two upgrades' models in one.

After expending the last few shots of a plug showing a Combine Suppressor exactly what the resistance thinks of traitors to humanity, Alyx's SMG cycles to the next plug; this process starts off like normal, with the old plug being extracted and dumped out the side (showing off the interesting plasma-ball-like effect on the inside of the chamber)...

...before a pair of manipulator arms grab the next plug out of the magazine...

...and the bolt/striker/thing shoves it into the chamber.

To top off this 3-plug magazine, Alyx must first open it; this is done by pushing the button conveniently added to the pistol grip with this upgrade, right where a modern pistol's magazine release would be.

Plugs can then be inserted; this is similar to the standard loading procedure, with the weapon grabbing the plug from its associated block and pulling it in, though the relevant locations and number of repetitions necessary are rather obviously different.

After that, simply push the magazine shut, and you're good to go. Like the Ratel, it can also be closed with a simple flick of the wrist (like the all-too-common, not-at-all-advisable technique used to close and damage revolvers), though also like the Ratel, this doesn't come through as well in a still image.

The special Combine-issued variant of the SMG; as mentioned, it has the extended magazine upgrade, but lacks the functionless second barrel that comes with Alyx's version. It also notably features a rear sight, unlike Alyx's version; this doesn't add much utility, however, as there's no front sight to line it up with. The marking on the heat shield says "TY" in the Combine alphabet (which is actually just a stylised version of Latin); what exactly this marking is supposed to mean is unclear. As a note of trivia, the SMG is both the last weapon acquired and the first one seen, with this version being used by the Combine troops sent to arrest Eli Vance in the first chapter.

Also noteworthy is the way that Combine units hold their SMGs; while it seems at first like a reasonable spot to grab, the barrel shroud's short length and tapered front (i.e. the exact opposite of a handstop) make this a somewhat inadvisable choice - even here, the Grunt's thumb is dangerously close to the muzzle.

"Pulse Rifle"

Combine Soldiers use a larger, rifle-configured variant of the SMG, essentially identical to the "Overwatch Standard-Issue Pulse Rifle" from Half-Life 2; no player-usable counterpart is available.

A Soldier stands frozen in time, aiming his Pulse Rifle at the spot where Alyx was back when he was still sentient. Like the Grunts' SMG (and the weapon's HL2 counterpart), it features a rear sight and no accompanying front sight.

The weapon's other side; presumably due to it being a purpose-made model exclusively for enemies (rather than a slightly-altered version of a player-usable weapon), the Pulse Rifle is notably simpler-looking than the SMG. It also lacks the large side-mounted magazine of the HL2 version. The marking on this weapon reads "GAR V"; again, what this means is unclear.

A look at the business end shows that the second "barrel" is both largely solid and continuous with the segment above it, and raises yet further questions about how any part of this device is meant to work. Such is the nature of alien technology.

Another frozen Combine soldier dies; their death animations are apparently connected to their AI, so disabling the latter causes them to simply stand there motionless, with their weapon and audio being the only real cues that anything's happened. The former point is the subject of this photo; upon their users' death, Combine weapons quickly turn black and fade out of existence. Precisely why this was done when the game already handwaves these weapons' unusability via the DNA-binding system isn't entirely clear.

Suppressor Machine Gun

Combine Suppressors wield a fictional machine gun with no player-usable counterpart; it is held similarly to the modified M134 Minigun seen in Predator, with a Lewis Gun-based barrel shroud and a large carrying handle vaguely reminiscent of the CETME Ameli. Interestingly, while the sound effects and noticeable pause before firing suggest a Gatling-type design (the weapon often being referred to as the "Pulse Minigun"), it seemingly has only one barrel, implying that the "spin-up" is actually some form of energy-related mechanic.

A sentience-suppressed Suppressor holds his MG; note the top/bottom grip, rather than the now-common chainsaw-style top/top grip.

A close-up view of the other side; the Lewis influence is quite apparent here, right down to the never-used bipod.

And, finally, a view that few live to see, and fewer live to describe. The single muzzle puts paid to any claim that this is some sort of Gatling gun (unless the Lewis-style shroud is supposed to be covering all of the barrels, but the shape of the shroud makes that unlikely); while the function of the gray bit at the left is unclear, the red object on top is most likely a non-visible laser emitter (probably IR, with the Suppressors' goggles letting them see outside the visible spectrum) to help manage an otherwise non-aimable weapon.

Grenade

The game's hand grenades are a completely fictitious design, bearing more resemblance to a tape measure than any sort of grenade; instead of a conventional pin or pull-cord, they are activated with a push of a button. Like the Mark 3-based "M83" grenades in HL2, they feature a flashing red LED and a beeping speaker that activate when the grenade is armed; the blinking and beeping gradually speed up as the grenade's fuse burns down.

Having come across the first grenades in the game, Alyx stops for a moment to inspect them. Keen-eyed viewers may notice that this is actually the room BEFORE the grenades appear; they were picked up and taken here, because the lighting in here is better.

Advancing to the room where the grenades are actually acquired, Alyx decides to try one out; to arm them, she pushes the large central button in with her thumb. It should go without saying that this is an extremely bad idea; the danger this poses is even acknowledged in-game, with grenades being easily (and, as one would expect, non-reversibly) armed by stray gunfire, though something as simple as a hard fall onto a well-placed pebble would probably have the same effect in reality. Considering that they've switched to more conventional, pin-based grenades by HL2, the Combine apparently realized their mistake.

Doing so causes the LED to turn on, the speaker to start beeping, the lever to fly skywards, and the grenade to spring open into a roughly spherical shape.

Taking a break from logical continuity for a moment to look at said lever; while it is fully internally detailed, it's still rather apparent that the player was never meant to pick these things up.

Getting back to the matter at hand, and tossing the grenade to a nearby Barnacle. The fuse lasts roughly 5 seconds, unless it's being used as a projectile for the shotgun-mounted grenade launcher mentioned above.

Clueless, the Barnacle accepts its "meal"...

...with predictable results.

Grenade storage is another topic worth noting; the maximum number of grenades Alyx can theoretically carry is 4 - two in her wrist pockets, and two in her hands (plus an extra one on the Shotgun's grenade launcher attachment, if she has it). However, in a VR game with a good physics engine and interactable props, the only thing needed to surpass this limit is a bit of creativity.

Mark 19 Grenade Launcher

The Strider battle at the end of "Breaking and Entering" is finished via a large Combine-manufactured repeating cannon; this appears to be more or less an oversized Mk 19 Grenade Launcher with some Combine embellishments. Unlike the actual Mark 19, the Combine weapon is manually-operated; running the charging handle cycles the action, and fires a shot whenever said action is closed.

Mark 19 Mod 3 Grenade Launcher on M3 tripod with 32-round belt box and current-production flash hider - 40x53mm

"Hey, do ya mind? I'm trying to take some screenshots here."

Muttering about "the nerve of some people these days", Alyx takes up the grenade launcher's controls and decides to give the Strider a piece of her mind.

Working the action; this only requires running the charging handle back and forth, but occurs in 3 distinct stages - first, the dustcover opens as the bolt slides back...

...then the "belt" (which lacks any obvious links, and thus presumably uses magnets or something) gets pulled further into the action, placing a round in the feed tray...

...and then the bolt goes forward as the dustcover closes, chambering (and immediately firing) the shell. No spent cases are ejected during this process, so these shells are presumably caseless.

Taking aim at the offending creature; the weapon lacks sights of any sort, so aiming is mostly a matter of guessing and adjusting. The fact that the Strider is consistently hammering the energy-based gunshield with a laser light show doesn't help.

Still, with a bit of trial and error...

...a shot will hit its mark. And then several more, since the Strider doesn't die from the first one. Luckily, the Combine have apparently figured out unlimited ammo, so your only limiting factor is time.

Having dealt with the long-legged nuisance, Alyx stops for a breather, and takes a look at the weapon's right side.

And the business end, for good measure; note the slotted flash hider, indicative of a current-production Mark 19. Or post-current, in this case.