A Nagant M1895 revolver is carried by Yuri Ismaylov (Nikola Duricko) in “Chapter Five: The NINA Project”. It is later used by Murray Bauman (Brett Gelman) and Joyce Byers (Winona Ryder) in the same episode.
The Smith & Wesson Model 19 is carried by Chief Calvin Powell (Rob Morgan), Officer Phil Callahan (John Paul Reynolds) and Officer Glenn Daniels (Jeff Sprauve) of the Hawkins Police Department throughout the season. It also seems to be carried by officers with the Lenora Hills Police Department in "Chapter Two: Vecna's Curse".
A nickel plated 6 inch Colt Python with rubber grips is purchased by Jason Carver (Mason Dye) at War Zone Army Navy Surplus in “Chapter Eight: Papa”. He refers to it as a ‘pretty .357’. He is later seen using it in “Chapter Nine: The Piggyback”. It should be noted that Jason's purchase is impossible and highly illegal, as Federal law mandates a minimum age of 21 to buy handguns while Jason, as a high school senior, is at most 19 years old.
The Colt M1911A1 is carried by various Military Police officers at Hawkins National Laboratory in flashbacks in the 1970’s. Military Police officers loyal to Dr. Martin Brenner (Matthew Modine) are seen with holstered 1911's whilst guarding the NINA Facility. A suppressed 1911 is also used by a US Army operative under the command of Lt. Colonel Jack Sullivan (Sherman Augustus) in “Chapter Four: Dear Billy”.
The Makarov PM is carried by various Soviet Army soldiers and prison guards, including Dmitri Antonov (Tom Wlaschiha). Jim Hopper (David Harbour), Murray Bauman (Brett Gelman) and Joyce Byers (Winona Ryder) are also seen using them in “Chapter Seven: The Massacre at Hawkins Lab” and “Chapter Eight: Papa”. In "Chapter Six: The Dive", Nancy Wheeler (Natalia Dyer) claims to have one at home and tries to retrieve it from the Upside-Down version of her house, only to fail due to a time anomoly. While she actually used a TT in Season 3, there were Makorovs she could have taken as well.
A Winchester Model 1200 with a ribbed field barrel is purchased by Nancy Wheeler (Natalia Dyer) for $120.99 with 20 shells in “Chapter Eight: Papa”. She later saws down the barrel for use in close quarter combat to widen pellet spread in "Chapter Nine: The Piggyback".
A Heckler & Koch MP5A3 with slimline handguard is carried by the leading Military Police officer (Jason Vail) loyal to Dr. Martin Brenner (Matthew Modine) at the NINA Facility in “Chapter Eight: Papa”.
Multiple Heckler & Koch MP5Ks with PDW stocks attached are used by Military Police officers loyal to Dr. Martin Brenner (Matthew Modine) at the NINA Facility in “Chapter Eight: Papa”. The MPs use MP5K-PDWs both with and/or without threaded tri lug barrels. As the PDW stock wouldn't be developed for another five years, this is a definite anachronism.
The AKM is carried by various Soviet Army soldiers and prison guards throughout the season. In “Chapter Nine: The Piggyback”, Jim Hopper (David Harbour) arms himself and Murray Bauman (Brett Gelman) AKM rifles from Yuri Ismaylov's (Nikola Duricko) stockpile, and in a continuity error Murray's AKM transforms into an Type 56 after he and Hopper trade weapons where it changes back into the former. Hopper then uses the weapon against the Demogorgon, firing one-handed several times. While the AK-74 had replaced it long ago in standard Russian service, it could be explained as being retained by rear-line prison guards for whom the latest and greatest is not needed.
In “Chapter Nine: The Piggyback”, Hopper's AKM turns into a Type 56 with slant muzzle break, which Murray Bauman (Brett Gelman) ends up with after Hopper takes the flamethrower. The weapon then chages to a regular AKM after the men swtich weapons again inside the prison.
Aside from the AKMSUs, genuine and period correct AKS-74U carbines are also seen carried by various Soviet Army soldiers and prison guards throughout the season, notably in "Chapter Four: Dear Billy". The Siberian sequences were filmed in Lithuania, so the presence of period correct Soviet era weaponry was probably simplified.
A M16 is carried slung over by a US Army soldier under the command of Lt. Colonel Jack Sullivan (Sherman Augustus) in the beginning of "Chapter Five: The Nina Project" and also carried by another soldier before starting an assault in “Chapter Eight: Papa”. The prong flash hider can be seen.
Error creating thumbnail: File missingOriginal M16 - 5.56x45mm - the first model, firing in a 20-round magazine, adopted in large numbers by the U.S. Air Force in Vietnam. This has the original 3-prong flash-hider. It would later be replaced by the upgraded M16A1.Error creating thumbnail: File missingThe pronged muzzle can be seen as soldiers search the Byers's house.
Colt M16A2
The Colt M16A2 is seen used by US Army soldiers under the command of Lt. Colonel Jack Sullivan (Sherman Augustus) briefly in "Chapter Two: Vecna's Curse" with A1 triangle handguard and from the rest on with standard A2 rounded handguards in "Chapter Four: Dear Billy", most notably by virtually all of the US Army soldiers during the assault at the NINA facility in “Chapter Eight: Papa”. A few of the US Army soldiers also carry M16A2 rifles with M203 grenade launchers with heatshield barrel shroud handguards during an assault in the same episode as the latter. Since Season 4 takes place in 1986, the M16A2 in the hands of the US Army soldiers is technically correct as the rifle model had just been adopted that year but would also not be as ubiquitous as of yet until the late 1980s. The M16A2s are also seen incorrectly firing fully automatically when the variant model of the rifle in real life is 3 round burst and semi automatic only.
A Heckler & Koch HK33A3 is briefly seen being carried by a few US Army soldiers under the command of Lt. Colonel Jack Sullivan (Sherman Augustus), notably by a soldier after he is shot by FBI Agent Harmon (Ira Amyx) in “Chapter Four: Dear Billy”. While not actual US Army issue, the SEALs did use Harrington and Richardson produced HK33s in Vietnam as the T223, and it can be assumed that Sullivan's men are using non-standard weapons deliberately for this deniable and illegal "black" operation.
A scoped Springfield M1A rifle in a woodland camouflage fiberglass stock is used by a heliborne sniper working for LTC Sullivan in “Chapter Eight: Papa”. The rifle is undoubtedly meant to be a M21 Designated Marksman Rifle Sniper Weapon System but upon closer inspection reveals the rifle lacking a fire/safety selector that a M14 and M21 normally would have, as seen during the reload scene. A plain wood stock non scoped M1A is briefly seen hanging on display inside War Zone Surplus in the same episode.
A few US Army soldiers under the command of Lt. Colonel Jack Sullivan (Sherman Augustus) carry M203 grenade launchers mounted on Colt M16A2 rifles during an assault in “Chapter Eight: Papa”.
