Constructed entirely of steel and plastic, with a shoulder stock which folds underneath the weapon, the Patchett L2A1 has some unusual features: for example, the bolt has helical grooves cut into the surface to remove dirt and fouling from the inside of the receiver to increase reliability. It uses a much-improved (over its predecessor) 30-round curved double-column box magazine which is inserted into the left side of the receiver. The magazine follower, which pushes the cartridge into the feed port, is equipped with rollers to reduce friction and the firing pin is designed so that it does not line up with the primer in the cartridge until the cartridge has entered the chamber. One of the primary user complaints is that it annoyingly - and sometimes painfully - pokes the user.
The Patchett L2A1 is of average damage. It possesses poor accuracy and manageable recoil, meaning that one will have little trouble dispatching a target at medium range. Its rate-of-fire is very low for an SMG, and while this may help somewhat with recoil control, it is not advisable to wield the Patchett in tight quarters.
The Patchett only holds 20 rounds per magazine with a total reserve capacity of 220 (275 with Fully Loaded), making it a sort of smaller, secondary version of the JP36 - with all the pros and cons of that rifle.
Due to its low total ammo, having the Fully Loaded skill, preferrably Aced, helps greatly in combat as the 25% total ammo increase grants the Patchett an entire extra magazine to use. It is one of the (very) few non-pistol weapons in PAYDAY 2 where the bonus ammo gained by this skill amounts to a full magazine.
Acing the SMG Specialist Ghost skill can help alleviating the Patchett's low rate-of-fire, bringing it up to 660, about on par with the Para.
The maximum concealment attainable for the Patchett is 27 (Short Barrel, Low Profile Suppressor or Stubby Compensator, Short Mag, and No Stock.). However, going with this build also means that the weapon will only hold a measly total of 10 rounds per magazine that can and will run out very quickly, in spite of the weapon's low firing rate.
Although the main flashlight has a toggle switch, the laser sight component of the LED Combo is pressure-activated, meaning the laser will stay on as long as the pressure switch is depressed. This switch is not placed where it should be, however (on foregrips, magazine wells, etc...) and is instead ziptied to the main taclight, leaving no plausible mean for the user to toggle it without awkwardly moving their off hand off the weapon and gripping the attachment itself.
Upon release, the default reticle of this sight was a chevron instead of the retail version's red dot. After the release of the Gage Mod Courier DLC, it was reverted to the regular sight's red dot.
It is functionally the same as the standard Military Red Dot Sight, but the sight's casing is tan instead of black with the line "A-10" scrawled on near the adjustment knob. The sticker on the lens cap's interior also says "I <3 Payday" instead of having a picture of an American flag.
This sight was based on the Aimpoint CompM2 optic. While it is portrayed as a high-zoom scope in-game, the CompM2 is actually a reflex sight, meaning it offers no magnification in reality.
The Patchett L2A1 was based on the Sterling SMG variant of the same name (Sterling L2A1, designated the Patchett Machine Carbine Mk.2 by the British Army), therefore making it one of the few weapons in the game to retain its real-world designation.
Equipping the Heatsinked Suppressed Barrel, the Short Mag, and the Folded Stock attachments, as well as a Military Red Dot Sight or a Milspec Scope causes the Patchett to strongly resemble the BlasTech E-11 rifle's various configurations (all of which were dressed up Sterling prop guns made by the movie studio's armorer) wielded by Imperial Stormtroopers in the Star Wars movie series.
Incidentally, the E11s were infamous for their poor accuracy, in which they couldn't hit any of the protagonists, allegedly due to high recoil despite being a directed-energy weapon, whilst the in-game iteration will also have very poor accuracy and stability.
As with most Sten models and derivatives in video games, the Patchett is held in the "Sten grip" position, with the user's left hand gripping onto the weapon's magazine and the entire gun is then held at a slight angle. This handgripping style is not advisable to do in reality as improper grip of the hand may displace the magazine, cause wear to the magazine catch, or otherwise create a misfeed by jamming it too tightly into the weapon. What would've been the correct grip position was to hold the Patchett like a rifle, with the wielder's left hand cradling the underside of its barrel shroud.
The description given on the Gage Historical Pack refers to the Sten Gun, which is the direct precursor to, but not the Sterling itself. The Sterling was developed quite late into the war and was only deployed in very early prototype stages for small-scale field tests, and the specific model featured in the game wasn't even designed until 1949, long after the war has ended.
The Patchett is the only Historical Pack firearm to lack an associated achievement.