A select-fire submachine gun platform based on the [[Heckler & Koch MP5A3|MP5]], itself a scaled-down version of the [[Heckler & Koch G3A3|G3]] rifle. It employs a unique roller-locked delayed blowback action, instead of a more traditional straight blowback (such as in the [[IMI UZI|Uzi]]) or a more modern, rifle inspired gas operation (like the [[SIG MPX]]).
The original MP5 was chambered in [[9x19mm Parabellum]]. The currently available production MP5 submachine guns are available in [[9x19mm Parabellum]] ([[MP5A3]], [[MP5K]]), [[.40 S&W]] ([[MP5/40A2]]) and [[10x25mm Auto]] ([[MP5/10A3]]).
Any ''full-size'' MP5 submachine gun is considered to be part of the MP5 family, which excludes including the short-barreled [[MP5K]].
! Caliber !! Compatible magazines !! Corresponding base models
|-
| '''[[9x19mm Parabellum]]''' || [[MP5 9mm magazines]] || [[Heckler & Koch MP5A3]], [[Heckler & Koch MP5K]]
|-
| '''[[10x25mm Auto]]''' || [[MP5 10mm/.40 magazines]] || [[Heckler & Koch MP5/10A3]]
|-
| '''Standard barrel''' || 8.9 inches || Muzzle: 3-lug mount || [[Heckler & Koch MP5A3]]<br/>[[Heckler & Koch MP5/10A3]]<br/>[[Heckler & Koch MP5/40A2]] || '''100''' || Original 8.9 inch barrel with 3-lug muzzle mount.
|-
| '''Short MP5K barrel''' || 4.5 inches || Muzzle: N/A<br/>Underbarrel: Integrated foregrip<br/><br/>May affect weapon category and class<sup>'''[[Maze Customs:Major mods#MP5 weapon categorization|(*)]]''' || [[Heckler & Koch MP5K]] || '''150''' || Installs the MP5K 4.5 inch barrel with no muzzle mounting point and the unique integrated foregrip.<br/>'''Not compatible''' with: '''Surefire 628''' and '''Quad rails''' handguards
|-
| '''MP5 Sound Dampened (MP5SD)''' || 5.7 inches || Muzzle: Integrated silencer || || '''900''' || Installs the MP5SD 5.7 inch integrally suppressed barrel, with matching handguards.
| '''Original''' || None || [[Heckler & Koch MP5A3]]<br/>[[Heckler & Koch MP5/10A3]]<br/>[[Heckler & Koch MP5/40A2]] || '''100''' || Original handguards with no features.
|-
| '''Surefire 628''' || Lights: Integrated weaponlight || || '''300''' || Special handguards with an integrated Surefire 628 light and appropriate on/off buttons. Sits low enough to avoid interfering with suppressors or muzzle brakes.<br/>'''Not compatible''' with: '''Short MP5K barrel'''
|-
| '''Quad rails''' || Lights: 2x Long interface<br/>Underbarrel: Long interface || || '''600''' || Quad-rail handguards to attach the lights, lasers, and underbarrel accessories of your choice.<br/>'''Not compatible''' with: '''Short MP5K barrel'''
|}
| '''UMP stock''' || '''FS''' || None || || '''150''' || [[UMP]]-style folding stock.
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| '''Endcap''' || '''N''' || Weight tier -1 <br/>May affect weapon category and class<sup>'''[[Maze Customs:Major mods#MP5 weapon categorization|(*)]]''' || || '''100''' || No stock at all. The rear of the receiver is simply covered by an endcap with a sling loop.
|}
=== MP5 weapon categorization ===
Depending on the selected configuration of modifications, your MP5's weapon category may change.
* If the weapon has both the '''Short MP5K barrel''' AND the '''Endcap''' (no stock), the weapon's Class changes to '''Class 3''', and the weapon's category changes to '''Auto pistol'''. Additionally, [[dual-wielding]] is allowed.
* Any other configuration is a '''Class 2 Submachine gun'''.