{
  "apiVersion": 1,
  "kind": "work-order",
  "purpose": "Taking the firearm apart for a job such as refinishing, and putting it back together to specification.",
  "firearm": {
    "slug": "fn-ps90",
    "name": "FN PS90",
    "manufacturer": {
      "id": "fn-herstal",
      "name": "FN Herstal"
    },
    "category": "carbine",
    "action": "blowback",
    "calibers": [
      "5.7x28mm"
    ],
    "alsoKnownAs": [
      "PS90",
      "FN PS90 Standard"
    ],
    "coversAlso": [],
    "page": "firearms/fn-ps90.html",
    "bundle": "api/v1/firearms/fn-ps90.json",
    "lastUpdated": "2026-10-29"
  },
  "notices": [
    "FN Herstal limits owner disassembly: Field strip into four groups (barrel support and upper rail group, moving parts group, butt plate, hammer group), and magazine disassembly. Nothing further.",
    "No torque values are recorded for this firearm. Get them from the manufacturer or a gunsmith; do not estimate."
  ],
  "disclaimer": {
    "headline": "Read this before you use anything here.",
    "points": [
      "This is a guide, not an authority. Entries are compiled from manufacturer manuals, technical manuals, published references, and community knowledge. Some of it comes from sources that are not authoritative, and some of it may simply be wrong.",
      "Always consult the manufacturer's manual for your specific firearm and serial-number range. Manufacturers change designs mid-production without renaming the model. The manual that shipped with your firearm outranks anything on this site.",
      "Consult a licensed gunsmith for anything beyond routine field stripping and cleaning, for any firearm you are unsure about, and for any procedure marked as gunsmith-recommended here.",
      "Treat every firearm as loaded. Verify it is unloaded, with the magazine removed and the chamber physically and visually checked, before any procedure in this database. Point it in a safe direction the entire time.",
      "Disassembly can damage a firearm or injure you. Springs are under tension, parts can launch, and reassembling a firearm incorrectly can make it unsafe to fire in a way that is not obvious from the outside. If a reassembled firearm does not pass a function check, stop and see a gunsmith.",
      "Torque values are shown in two groups. Values from the manufacturer or the issuing military are shown as such, with the document they came from. Values reported by anyone else — parts makers, gunsmithing publishers, articles, forums — are shown separately with who said them, how reliable that source is, and their exact words. Those are not specifications. Confirm any torque value with the manufacturer or a licensed gunsmith before relying on it.",
      "Nothing here is legal advice. Firearms law varies by country, state, and city, and some modifications or configurations are regulated or prohibited. You are responsible for knowing and following the law where you are.",
      "No warranty of any kind. Contributors and maintainers accept no liability for damage, injury, or loss arising from use of this material."
    ],
    "page": "disclaimer.html",
    "legal": {
      "summary": "Legal notice: this material is third-party information compiled from sources of varying reliability and is provided for general informational and educational purposes only. It is not gunsmithing, technical, safety or legal advice, it is not verified or endorsed by any manufacturer, and it must not be taken as fact. Any work on a firearm beyond the routine field stripping described in its own owner's manual should be performed only by a licensed and insured gunsmith. You use this material entirely at your own risk. Fundamental Build LLC and the project's contributors make no warranty of any kind and accept no liability for death, injury, damage or loss arising from its use. Full terms: LEGAL.md.",
      "page": "legal.html",
      "notice": "https://github.com/Fundamental-build-LLC/Pew-Takedown/blob/main/LEGAL.md"
    }
  },
  "sourcing": {
    "confidence": "high",
    "verification": "manufacturer-manual-verified"
  },
  "manufacturerDisassembly": {
    "status": "limited",
    "limit": "Field strip into four groups (barrel support and upper rail group, moving parts group, butt plate, hammer group), and magazine disassembly. Nothing further.",
    "statement": "FN says the field strip is enough for thorough cleaning and that further disassembly should be done only by an FN Recommended Service Center. It also says removing metal from the barrel or modifying the firing mechanism may lead FN to refuse service.",
    "source": {
      "title": "FN PS90 Autoloading Carbine Owner's Manual (1605, OM 3810054200)",
      "publisher": "FN America, LLC",
      "reliability": "primary",
      "url": "https://fnamerica.wpenginepowered.com/wp-content/uploads/2016/10/1605_PS90_Owners_Manual_v3.pdf",
      "page": "25",
      "pdfPage": 25,
      "pageUrl": "https://fnamerica.wpenginepowered.com/wp-content/uploads/2016/10/1605_PS90_Owners_Manual_v3.pdf#page=25",
      "quote": "This level of disassembly is sufficient to perform thorough cleaning : further disassembly should only be carried out by a FN Recommended Service Center / your departmental armorer."
    }
  },
  "recalls": [],
  "shopTier": {
    "tier": 3,
    "group": "rifle",
    "rating": "Pew-Takedown editorial rating (1 easy – 3 hardest), not the manufacturer's",
    "reason": "Mostly polymer, with a field strip into four groups that takes seconds. Past that, the hammer group and frame/trigger group are polymer assemblies held by pins and springs, and FN restricts them to its service centre or an armorer. The hammer group has to be in a particular state when it comes apart. With no published parts list and armorer-only internals, it sits with the hardest rifles here on uncertainty as much as evidence.",
    "confidence": "low",
    "partCount": null,
    "painPoints": [
      {
        "issue": "FN limits the owner to the four-group field strip; anything further (hammer group, trigger group, barrel support) is service-centre/armorer work.",
        "during": "both",
        "source": {
          "title": "FN PS90 Autoloading Carbine Owner's Manual (1605, OM 3810054200)",
          "publisher": "FN America, LLC",
          "reliability": "primary",
          "url": "https://fnamerica.wpenginepowered.com/wp-content/uploads/2016/10/1605_PS90_Owners_Manual_v3.pdf",
          "page": null,
          "pdfPage": null,
          "pageUrl": null,
          "quote": "further disassembly should only be carried out by a FN Recommended Service Center / your departmental armorer."
        }
      },
      {
        "issue": "The hammer must be cocked (raised) before the hammer group comes out; if the trigger has been pulled with the moving parts out, the carbine has to be reassembled and re-cocked first.",
        "during": "both",
        "source": {
          "title": "FN PS90 Autoloading Carbine Owner's Manual (1605, OM 3810054200)",
          "publisher": "FN America, LLC",
          "reliability": "primary",
          "url": "https://fnamerica.wpenginepowered.com/wp-content/uploads/2016/10/1605_PS90_Owners_Manual_v3.pdf",
          "page": null,
          "pdfPage": null,
          "pageUrl": null,
          "quote": "If the trigger has been pulled after the removal of the moving parts, reassemble the carbine, cock the hammer by pulling the cocking handle completely rearward and then start disassembling again."
        }
      },
      {
        "issue": "The hammer group is a polymer assembly held together by pins and springs; owners advise leaving it to a gunsmith who knows the PS90.",
        "during": "both",
        "source": {
          "title": "FN PS90 review/thread",
          "publisher": "Canadian Gun Nutz",
          "reliability": "anecdotal",
          "url": "https://www.canadiangunnutz.com/forum/goto/post?id=3776538",
          "page": null,
          "pdfPage": null,
          "pageUrl": null,
          "quote": "Unless you are a gunsmith familiar with the PS90 I would not suggest getting your punches and pliers out and stripping the gun any further."
        }
      }
    ],
    "minutes": {
      "strip": 50,
      "rebuild": 80,
      "basis": "estimated",
      "note": "Estimate: field strip into four groups, then the hammer group, frame/trigger group, barrel support/rail, butt plate and magazine catch. Rebuild longer: polymer internals with pins and springs, and the function check. High uncertainty.",
      "source": null
    },
    "stripScope": [
      {
        "assembly": "Barrel support and upper rail group",
        "removes": [
          "barrel and support",
          "upper rail",
          "sights"
        ]
      },
      {
        "assembly": "Frame and trigger group",
        "removes": [
          "trigger system",
          "fire selector",
          "magazine catch",
          "ejection chute"
        ],
        "tools": [
          "pin punches"
        ]
      },
      {
        "assembly": "Moving parts group",
        "removes": [
          "breech block",
          "guide rods and return springs"
        ]
      },
      {
        "assembly": "Hammer group",
        "removes": [
          "hammer group (polymer, pins and springs)"
        ],
        "tools": [
          "pin punches"
        ]
      },
      {
        "assembly": "Butt plate",
        "removes": [
          "butt plate"
        ]
      }
    ],
    "hardware": null,
    "specialTools": [
      {
        "tool": "Pin punches (polymer-safe)",
        "usedFor": "Hammer and trigger group pins"
      },
      {
        "tool": "Sight adjustment tool",
        "usedFor": "Rail sight"
      }
    ],
    "fitOnRebuild": [
      {
        "check": "Hammer group dry",
        "why": "FN: hammer group components are never lubricated",
        "source": {
          "title": "FN PS90 Autoloading Carbine Owner's Manual (1605, OM 3810054200)",
          "publisher": "FN America, LLC",
          "reliability": "primary",
          "url": "https://fnamerica.wpenginepowered.com/wp-content/uploads/2016/10/1605_PS90_Owners_Manual_v3.pdf",
          "page": null,
          "pdfPage": null,
          "pageUrl": null,
          "quote": "Components of the hammer group may never be lubricated"
        }
      },
      {
        "check": "Function check",
        "why": "Safety, internal safety sear and trigger reset after the hammer group goes back",
        "source": null
      },
      {
        "check": "Zero",
        "why": "Optic/sight on the barrel support must be re-zeroed",
        "source": null
      }
    ],
    "assessed": "2026-10-29"
  },
  "videos": [],
  "configurations": [],
  "tools": [],
  "phases": [
    {
      "id": "clear",
      "title": "Clear and make safe",
      "steps": [
        {
          "n": 1,
          "instruction": "Point the carbine in a safe direction with your finger off the trigger and set the fire selector to 'S' (safe)."
        },
        {
          "n": 2,
          "instruction": "Pull the magazine catch rearward to release the magazine, then remove it.",
          "warning": "With the magazine on the carbine, the last two cartridges and the one in the chamber cannot be seen.",
          "partsFreed": [
            "Magazine"
          ]
        },
        {
          "n": 3,
          "instruction": "Pull the cocking handle completely rearward and release it to extract and eject any cartridge from the chamber. Repeat at least three times."
        },
        {
          "n": 4,
          "instruction": "Pull the cocking handle completely rearward and hold it, then look through the magazine opening into the chamber to make sure it is empty.",
          "tip": "If a cartridge is still there, release the handle and pull it fully rearward again to extract it."
        },
        {
          "n": 5,
          "instruction": "Release the cocking handle, make sure the magazine itself is empty, and remove all ammunition from the work area."
        }
      ],
      "videos": []
    },
    {
      "id": "disassemble",
      "title": "Disassemble",
      "videos": [],
      "procedures": [
        {
          "procedure": "field-strip",
          "title": "Field Strip",
          "level": "field-strip",
          "configuration": false,
          "steps": [
            {
              "n": 1,
              "instruction": "Complete the Clear and Make Safe procedure, with the magazine removed."
            },
            {
              "n": 2,
              "instruction": "Pull the cocking handle completely rearward and release it, so the hammer is cocked.",
              "warning": "From here on, do not pull the trigger. The moving parts group and the hammer group can only be removed with the hammer cocked."
            },
            {
              "n": 3,
              "instruction": "While pushing down on the barrel support lock, move the barrel support and upper rail group slightly forward, then slide it completely out of the frame.",
              "partsFreed": [
                "Barrel support and upper rail group"
              ]
            },
            {
              "n": 4,
              "instruction": "Push the moving parts group forward through the magazine opening, then carefully slide it completely out of the frame.",
              "partsFreed": [
                "Moving parts group"
              ]
            },
            {
              "n": 5,
              "instruction": "At the rear, slide the butt plate up and off the frame.",
              "partsFreed": [
                "Butt plate"
              ]
            },
            {
              "n": 6,
              "instruction": "While raising the hammer group release lever, pull the hammer group slightly rearward to release it, then slide it completely out of the frame.",
              "tip": "If the hammer group will not come out, the hammer has been decocked. Reassemble, cock the carbine with the cocking handle and start again.",
              "partsFreed": [
                "Hammer group"
              ]
            }
          ]
        },
        {
          "procedure": "magazine-disassembly",
          "title": "Disassemble the Magazine",
          "level": "detail-strip",
          "configuration": false,
          "steps": [
            {
              "n": 1,
              "instruction": "Remove the magazine and unload it completely."
            },
            {
              "n": 2,
              "instruction": "With your index finger, press the magazine bottom lock through the hole in the magazine bottom plate."
            },
            {
              "n": 3,
              "instruction": "Holding the bottom lock in, move the magazine bottom plate sideways until it disengages from the magazine body.",
              "warning": "The magazine bottom lock is under the force of the magazine follower spring.",
              "partsFreed": [
                "Magazine bottom plate"
              ]
            },
            {
              "n": 4,
              "instruction": "Carefully release the pressure on the magazine follower assembly and take it out of the magazine body.",
              "partsFreed": [
                "Magazine bottom lock",
                "Magazine follower assembly"
              ]
            },
            {
              "n": 5,
              "instruction": "Hold the magazine body slightly inclined to remove the two rollers.",
              "partsFreed": [
                "Rollers (2)"
              ]
            }
          ]
        }
      ]
    },
    {
      "id": "refinish",
      "title": "Refinish",
      "components": [
        {
          "name": "Barrel support and upper rail group",
          "procedure": "field-strip",
          "level": "field-strip",
          "step": 3
        },
        {
          "name": "Moving parts group",
          "procedure": "field-strip",
          "level": "field-strip",
          "step": 4
        },
        {
          "name": "Butt plate",
          "procedure": "field-strip",
          "level": "field-strip",
          "step": 5
        },
        {
          "name": "Hammer group",
          "procedure": "field-strip",
          "level": "field-strip",
          "step": 6
        },
        {
          "name": "Magazine bottom plate",
          "procedure": "magazine-disassembly",
          "level": "detail-strip",
          "step": 3
        },
        {
          "name": "Magazine bottom lock",
          "procedure": "magazine-disassembly",
          "level": "detail-strip",
          "step": 4
        },
        {
          "name": "Magazine follower assembly",
          "procedure": "magazine-disassembly",
          "level": "detail-strip",
          "step": 4
        },
        {
          "name": "Rollers (2)",
          "procedure": "magazine-disassembly",
          "level": "detail-strip",
          "step": 5
        }
      ],
      "manufacturerPartsList": null,
      "partsDiagrams": [],
      "materials": [],
      "note": "The components the procedures above separate. Coating, masking and cure are outside this database; follow your coating system's instructions. A part the manufacturer marks \"factory fit\" should not be swapped or reworked."
    },
    {
      "id": "reassemble",
      "title": "Reassemble",
      "videos": [],
      "procedures": [
        {
          "procedure": "magazine-disassembly",
          "title": "Disassemble the Magazine",
          "configuration": false,
          "steps": null,
          "instruction": "Reverse the steps of \"Disassemble the Magazine\"."
        },
        {
          "procedure": "magazine-reassembly",
          "title": "Reassemble the Magazine",
          "configuration": false,
          "steps": [
            {
              "n": 1,
              "instruction": "Make sure all magazine parts are clean."
            },
            {
              "n": 2,
              "instruction": "Insert the two rollers into the magazine body, one behind the other."
            },
            {
              "n": 3,
              "instruction": "Insert the magazine follower assembly, oriented as shown on the pictogram on the side of the magazine body."
            },
            {
              "n": 4,
              "instruction": "Push the magazine bottom lock in and hold it flush with the edge of the magazine body, then slide the magazine bottom plate back into position.",
              "tip": "The bottom plate only slides back on while the bottom lock is held flush."
            },
            {
              "n": 5,
              "instruction": "Make sure the magazine bottom plate locks into position."
            }
          ],
          "instruction": null
        },
        {
          "procedure": "reassembly",
          "title": "Reassembly",
          "configuration": false,
          "steps": [
            {
              "n": 1,
              "instruction": "Make sure every group is clean."
            },
            {
              "n": 2,
              "instruction": "Holding the hammer group release lever raised, slide the hammer group into the frame until it locks."
            },
            {
              "n": 3,
              "instruction": "Slide the butt plate back down onto the rear of the frame."
            },
            {
              "n": 4,
              "instruction": "Slide the moving parts group into the frame with its raised surface on top, until it locks into position."
            },
            {
              "n": 5,
              "instruction": "Pressing the barrel support lock, slide the barrel support and upper rail group into the frame until it locks.",
              "warning": "Check that each group has locked into position before going on."
            },
            {
              "n": 6,
              "instruction": "Fit an empty magazine, point the carbine in a safe direction, and pull the trigger to decock the hammer.",
              "warning": "Make sure the magazine and the chamber are really empty before you pull the trigger."
            }
          ],
          "instruction": null
        }
      ]
    },
    {
      "id": "torque",
      "title": "Torque",
      "coverage": "none-recorded",
      "manufacturer": [],
      "reported": [],
      "notes": "FN's owner's manual gives no torque values."
    },
    {
      "id": "function-check",
      "title": "Function check",
      "checks": [
        "Every group locks into position on reassembly; none can be pulled out without its lock or release lever.",
        "With an empty magazine fitted and the chamber empty, the hammer falls when the trigger is pulled.",
        "If the carbine does not fire or function, check that the fire selector is not on 'S', that it has been cocked, and that it has been reassembled correctly — FN's own troubleshooting order."
      ],
      "videos": []
    }
  ],
  "troubleshooting": [],
  "sources": [
    {
      "n": 1,
      "id": "fn-ps90-manual",
      "title": "FN PS90 Autoloading Carbine Owner's Manual (1605, OM 3810054200)",
      "publisher": "FN America, LLC",
      "reliability": "primary",
      "url": "https://fnamerica.wpenginepowered.com/wp-content/uploads/2016/10/1605_PS90_Owners_Manual_v3.pdf",
      "accessed": "2026-10-11"
    },
    {
      "n": 2,
      "id": "tier-eca7bae3",
      "title": "FN PS90 review/thread",
      "publisher": "Canadian Gun Nutz",
      "reliability": "anecdotal",
      "url": "https://www.canadiangunnutz.com/forum/goto/post?id=3776538",
      "accessed": "2026-10-29"
    }
  ]
}