Not eligible as a main article since it's a mobile game, so I'll work on it here. Sadly, my graphics settings are restricted to low quality.
The following weapons appear in the video game Call of Duty: Mobile:
Custom Springfield Armory M1911
The "J358" is a revolver loosely based on the Smith & Wesson Model 327 Performance Center M&P R8. It should be noted that the shortened .44 Smith & Wesson Model 629 Stealth Hunter from Call of Duty Online was clearly used as a base model.
It has wooden grips, and uses .45 caliber ammunition in Battle Royale mode. It holds 6 rounds by default, but somehow has an "extended mag" attachment option that increases the capacity to 8 rounds (which actually matches the cylinder capacity of the real S&W Model 327).
The Armsel Protecta appears. It uses the Call of Duty Online model, and is still called a "Striker" and depicted as semi-automatic.
The "KRM-262" pump-action shotgun from Black Ops III was added in Season 3.
SRM Arms Model 1216
The SRM Arms Model 1216 appears as the "HS2126". Unlike its counterpart from Black Ops II, one pull of the trigger automatically fires four rounds before rotating the magazine, essentially making it a burst-firing shotgun.
Winchester Model 1887
A heavily modified sawed-off Winchester Model 1887 appears as the "HS0405".
The "PDW-57", another P90-based SMG previously appearing in Black Ops II, is featured in the game.
The "GKS", a submachine gun seemingly inspired by the POF PSG and previously appearing in Black Ops 4, was added during Season 5.
Heckler & Koch MP5A3
The Heckler & Koch MP5A3 was added in Season 7 as the "QQ9". It uses the model of the "Strapped" blueprint from Call of Duty: Modern Warfare, albeit with the sling removed. That blueprint essentially consists of an MP5A3 fitted with a handguard which is a hybrid between HK Parts MP5, 94 & HK53 Key Mod Handguard and Midwest Industries MP5 M-LOK handguard and a top rail which for some reason is fitted with a quick detach lever from EOTech holographic sights implying that the top rail can be removed quickly, though how exactly this could work in reality remains unfathomable.
The "Flood" variant re-adds the sling, and is equipped with the "FORGE TAC Ultralight" stock from Modern Warfare, along with a straight magazine looking similar to the 10mm Auto magazine from that game.
The "HG 40", a futuristic MP40 from Black Ops III, appears in the game with even more alterations to the model.
The Modern Sub Machine Carbine appears in the game.
The Ruger MP9-based "Pharo" from Black Ops III was added in Season 2.
The "Razorback" from Black Ops III, a submachine gun bearing a resemblance to the fictional "Thor PDW", was added in Season 2.
Rifles & Carbines
The AK-102 returns from Call of Duty Online as the "AK117".
The same custom built FAL rifle known as "Maverick" in Ghosts returns as the "AK-117 - Kit Bag".
The AKM appears, still referred to as the earlier AK-47.
The "Pumpkin Head" variant is a Halloween-decorated rifle based on Black Ops 4’s "KN-57" (which itself was based on the 2015 prototype of the AK-12). Like that weapon, it is loaded with a 5.45x39mm magazine.
The AKS-74U appears, modeled after the heavily modified version from Call of Duty Online, and still classed as a submachine gun. The in-game name was changed from "AKS-74U" to "RUS-79U" during Season 3.
The modified AKU-94 from Call of Duty Online returns as the "BK57".
A custom AR-15-patterned rifle appears as the "M4". It consists of a hybrid upper receiver with its right side being from VLTOR MUR while the left is similar to Cross Machine Tools receiver with grooves like JP Enterprises CTR-02, a Geissele Super Dynamic trigger, a Magpul trigger guard and a Magpul pistol grip. It has a handguard which appears to be a hybrid between HWK KeyMod Free Float Handguard, Titan Handguard and Fortis Night Rail and a stock that appears to be a hybrid between a Magpul MOE SL and a Steyr AUG's stock. It also has a Raptor charging handle, a shark style muzzle brake and the magazine looks like it has a built in plate similar to the UTG polymer magazines.
The FN SCAR-H will be added in Season 8 as the "DR-H". It uses the model of "The Traitor" blueprint from Call of Duty: Modern Warfare, which has an altered receiver, a rail extension, and a stock inspired by a Bushmaster ACR's folding stock.
The "HBRa3" from Advanced Warfare, a futuristic weapon based on the Robinson Armament XCR, was added to the game in Season 3.
Heckler & Koch G36K
A heavily modified Heckler & Koch G36K appears in the game. It is referred to as the "LK24", and the model takes some design cues from the "G37H" seen in Call of Duty Online. It lacks a carrying handle, and has a custom handguard and telescoping stock, and an AR fire control group. While H&K does offer such fire control lowers for G36 rifles, the in-game version is different, as it has "Safe"/"Semi" markings as opposed to the H&K bullet pictograms.
The "Royal Crimson" variant gains a rail top carry handle, along with various differences including the fire selector, handguard and stock.
The "HVK-30", a carbine that appears to be a futuristic FN FAL derivative, returns from Black Ops III. It was added in Season 5.
The "ICR-1" from Black Ops III, a futuristic assault rifle based on the Heckler & Koch HK416, was added in Season 2.
The AK-200-esque "KN-44" from Black Ops III was added during Season 4. Prior to this, the AK-47 had a variant called "Red Action", which is based on that same "KN-44".
The M16A4 appears simply as the "M16". It uses the Modern Warfare Remastered model with some minor alterations.
The "Man-O-War" from Black Ops III was added in Season 2.
Accuracy International AS50
The Accuracy International AS50 appears as the "Arctic .50", similarly to Call of Duty Online.
The "DL Q33" is a bolt-action sniper rifle with some parts inspired by the Cadex Defence Dual Strike Chassis.
The "Locus", a futuristic sniper rifle based on the PGM Mini-Hecate and previously appearing in Black Ops III and Black Ops 4, was added to the game in Season 2.
The "Outlaw", a bolt-action revolving (yeah...) sniper rifle seemingly inspired by a Blaser R93 and previously appearing in Black Ops 4, was added during Season 6.
The "XPR-50", a semi-automatic sniper rifle somewhat resembling the bolt-action Barrett Model 98 Bravo, returns from Black Ops II and Black Ops III.
DS Arms RPD
The RPD from Call of Duty Online, looking similar to a DS Arms RPD, appears in the game.
Handheld General Dynamics GAU-19/A
The futuristic handheld General Dynamics GAU-19/A from Black Ops II returns as the "Death Machine". It is available as an "operator skill", and is also equipped on the "XS1 Goliath" armor killstreak.
The KAC ChainSAW was added in Season 7 as the "Chopper". Its model is taken from Call of Duty: Ghosts, though the proper circular vent holes have been replaced by elongated ones. The "Chain Reaction" variant is fitted with a unusable Spike's Tactical "Havoc" flare launcher, whereas the base weapon only has the launcher's mounting system.
A modified L86A1 appears as the "UL736".
The "M4LMG", a squad automatic weapon seemingly based on a Barrett REC7, returns from Call of Duty Online.
Norinco QBB Hybrid
A hybrid between the QBB-95-1 and the QBB-97 appears as the "S36". It has a selector switch above the pistol grip like the QBB-95-1, but feeds from an AR-15 style magazine like the QBB-97, as well as having a QBZ-95 style trigger guard.
The "FHJ-18 AA" from Black Ops II appears with a new model, and with the "AA" suffix removed from the name.
The Pansarskott m/86 from Call of Duty Online returns as the "SMRS".
The "War Machine" is a futuristic grenade launcher based on the Milkor MGL Mk 1L. It is available as an "operator skill".
"Cluster Smoke Grenade"
The "Cluster Smoke Grenade" is a fictional smoke grenade loosely based on the M47 CS grenade. It is exclusive to Battle Royale mode, and is available to the Smoke Bomber class.
M26 hand grenade
Three unusable M26 hand grenades can be seen on Firebreak's character model.
M83 smoke grenade
What appears to be the same M83 Smoke Grenade model from Call of Duty Online is part of the Terrance Brooks skin.
The Browning M2HB is available for use on the drivable pseudo PL-01 tanks added to Battle Royale in Season 7. It is referred to as "Tank Machine Gun".
FIM-92 Stinger Dual Mount System
The same mockup of the FIM-92 Stinger Dual Mount System seen in Call of Duty: Black Ops and Call of Duty Online appears as the SAM Turret scorestreak. It is also seen in the practice range (the latter having been added in Season 7), where it is used to rather comically launch rockets at an impossible angle and absurdly slow speed as to emulate skeet shooting.
General Dynamics GAU-19/A
A tripod-mounted version of the aforementioned GAU-19/A is used for the unmanned sentry gun killstreak. The gun is also mounted on the "Antelope A20" assault vehicle in Battle Royale mode.
General Dynamics M197 Vulcan
The General Dynamics M197 Vulcan is the chin armament of the "Stealth Chopper" scorestreak, a fictional helicopter based on the RAH-66 Commanche.
Unusable low poly machine guns seemingly supposed to represent the M240D can be seen mounted on some tanks.
A Single Action Army revolver is seen in the Wild West in-game comic.