{ "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": "hk-g3", "name": "Heckler & Koch G3 / PTR-91", "manufacturer": { "id": "heckler-koch", "name": "Heckler & Koch" }, "category": "rifle", "action": "roller-delayed-blowback", "calibers": [ "7.62x51mm NATO", ".308 Winchester" ], "alsoKnownAs": [ "G3A3", "HK91", "PTR-91", "CETME (predecessor)" ], "coversAlso": [ "G3A3 and G3A4", "HK91", "PTR-91", "CETME Model C (related design)" ], "page": "firearms/hk-g3.html", "bundle": "api/v1/firearms/hk-g3.json", "lastUpdated": "2026-10-29" }, "notices": [ "This work order is written for the Heckler & Koch G3 / PTR-91. It is reported to cover G3A3 and G3A4; HK91; PTR-91; CETME Model C (related design) — if the firearm on the bench is one of those, check the torque notes: values do not always carry over.", "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": "medium", "verification": "armorer-manual-verified" }, "manufacturerDisassembly": { "status": "not-recorded", "limit": null, "statement": null, "source": null }, "recalls": [], "shopTier": { "tier": 2, "group": "rifle", "rating": "Pew-Takedown editorial rating (1 easy – 3 hardest), not the manufacturer's", "reason": "PTR's list has 71 key numbers (76 pieces) including the trigger pack. The barrel stays pressed and pinned in the receiver, so the work is the trigger pack (hammer, pressure fork, springs), the bolt head rollers, the cocking support roll pin, and a rear sight with loose balls and springs. Bolt gap must be measured after reassembly. Several traps but nothing timed.", "confidence": "medium", "partCount": { "value": 71, "kind": "line-items", "covers": "PTR-91 GI complete rifle incl. trigger pack internals and bolt group (76 pieces)", "basis": "manufacturer-parts-list", "source": { "title": "PTR Roller-Delayed Blowback Weapon Systems Owner's Manual, Models .308 and 7.62x39", "publisher": "PTR Industries, Inc.", "reliability": "primary", "url": "https://www.ptr-us.com/wp-content/uploads/2023/01/PTR-.308-and-7.62x39-Owners-Manual.pdf", "page": "pp. 12-13 (PTR Firearm Exploded View/Par", "pdfPage": null, "pageUrl": null, "quote": "CONTACT SPRING, CLOSING CAP" } }, "painPoints": [ { "issue": "PTR stops the owner at the bolt group and sends any further strip (trigger pack, cocking support, sights) to a gunsmith.", "during": "both", "source": { "title": "PTR Roller-Delayed Blowback Weapon Systems Owner's Manual, Models .308 and 7.62x39", "publisher": "PTR Industries, Inc.", "reliability": "primary", "url": "https://www.ptr-us.com/wp-content/uploads/2023/01/PTR-.308-and-7.62x39-Owners-Manual.pdf", "page": null, "pdfPage": null, "pageUrl": null, "quote": "No further disassembly of the firearm is either necessary, or recommended, beyond this point." } }, { "issue": "The bolt head has to be clocked to the locking lever, rollers squeezed in and turned to the slot before the carrier goes back.", "during": "reassembly", "source": { "title": "PTR Roller-Delayed Blowback Weapon Systems Owner's Manual, Models .308 and 7.62x39", "publisher": "PTR Industries, Inc.", "reliability": "primary", "url": "https://www.ptr-us.com/wp-content/uploads/2023/01/PTR-.308-and-7.62x39-Owners-Manual.pdf", "page": null, "pdfPage": null, "pageUrl": null, "quote": "squeeze the bolt head rollers into the bolt head to move the bolt head forward slightly" } }, { "issue": "The rear sight drum sits on loose springs and plungers, and the sight base on a ball and spring; they are not captive and fly when the drum comes off.", "during": "both", "source": { "title": "MP-5 Armorers Instruction", "publisher": "Heckler & Koch, Inc. International Training Division", "reliability": "primary", "url": "https://archive.org/download/MManuals/HkMp5ArmorersManual.pdf", "page": null, "pdfPage": null, "pageUrl": null, "quote": "WATCH THE SPRINGS AND PLUNGERS UNDER THE TOOL, THEY ARE NOT CAPTIVE" } }, { "issue": "The cocking handle support is held by a clamping sleeve (roll pin) that only lines up with both holes in one handle position.", "during": "both", "source": { "title": "MP-5 Armorers Instruction", "publisher": "Heckler & Koch, Inc. International Training Division", "reliability": "primary", "url": "https://archive.org/download/MManuals/HkMp5ArmorersManual.pdf", "page": null, "pdfPage": null, "pageUrl": null, "quote": "When the clamping sleeve is centered in the top access hole it is not in alignment in the bottom hole." } }, { "issue": "HK's own armorer kit for the G3 includes straightening mandrels for the stamped receiver and cocking tube, plus gauges for symmetry and headspace.", "during": "both", "source": { "title": "G3 Armorer's Manual, Instructions for Maintenance and Repair, Cal. 7.62 mm x 51", "publisher": "Heckler & Koch", "reliability": "primary", "url": "https://archive.org/download/lots-of-gun-pdfs-firearms-manuals/Gun%20PDFs/hk_g3.pdf", "page": null, "pdfPage": null, "pageUrl": null, "quote": "Straightening mandrel for cocking lever housing" } } ], "minutes": { "strip": 55, "rebuild": 80, "basis": "estimated", "note": "Estimate: field strip, trigger pack (hammer, pressure fork and spring, sear, trigger, ejector, safety), mag catch and release lever, cocking lever and support (clamping sleeve), cocking tube cap, rear sight drum and base (balls/springs), front sight, handguard, flash hider, stock and back plate, bolt head and carrier. Rebuild longer for the trigger pack springs, rear sight detents and the bolt-gap", "source": null }, "stripScope": [ { "assembly": "Trigger pack / grip", "removes": [ "hammer, pressure fork and hammer spring", "trigger, sear, trigger spring, sear spring, bushing and pins", "ejector, pivot and spring", "safety selector and shaft", "pistol grip" ], "tools": [ "roll-pin punches" ] }, { "assembly": "Receiver", "removes": [ "magazine catch, push button, contact piece, spring, clamping sleeve", "mag release lever and bushing", "charging lever, support and elbow spring (H groove pin)", "cocking tube cap, compression bolt and contact spring", "rear sight drum, base, springs, balls, screw", "front sight holder/blade and clamping sleeve", "flash hider", "handguard and pin" ], "tools": [ "HK rear sight tool", "roll-pin punches" ] }, { "assembly": "Bolt group and stock", "removes": [ "bolt head, extractor, spring and clamping sleeve, rollers and retainer", "locking piece, firing pin and spring", "back plate, buffer, recoil spring and rod", "buttstock and pins" ] } ], "hardware": { "pins": 13, "springs": 12, "detents": 1, "basis": "counted from the PTR parts list in partCount" }, "specialTools": [ { "tool": "HK rear sight adjustment tool", "usedFor": "Rear sight drum removal" }, { "tool": "Roll-pin punches (2 mm, 2.5 mm, 4 mm)", "usedFor": "Clamping sleeves in the trigger pack, mag catch, front sight, cocking support" }, { "tool": "Feeler gauges", "usedFor": "Bolt gap" }, { "tool": "Flash hider wrench", "usedFor": "Flash hider/spring ring" } ], "fitOnRebuild": [ { "check": "Bolt gap", "why": "Measured with feeler gauges after reassembly; out of range means roller/locking piece work", "source": { "title": "PTR Roller-Delayed Blowback Weapon Systems Owner's Manual, Models .308 and 7.62x39", "publisher": "PTR Industries, Inc.", "reliability": "primary", "url": "https://www.ptr-us.com/wp-content/uploads/2023/01/PTR-.308-and-7.62x39-Owners-Manual.pdf", "page": null, "pdfPage": null, "pageUrl": null, "quote": "Safe, reliable, and acceptable bolt gap measurements for ALL PTR products after break-in will fall between .010”-.018” (.254 mm- .457mm)." } }, { "check": "Rear sight zero", "why": "The drum and base come off and the rifle must be re-zeroed", "source": null }, { "check": "Trigger function", "why": "Pressure fork and hammer spring seating checked with a function check", "source": null } ], "assessed": "2026-10-29" }, "videos": [], "configurations": [], "tools": [], "phases": [ { "id": "clear", "title": "Clear and make safe", "steps": [ { "n": 1, "instruction": "Point the muzzle in a safe direction and keep your finger off the trigger." }, { "n": 2, "instruction": "Place the selector on safe if the design allows it with the action in its current state." }, { "n": 3, "instruction": "Press the magazine release and remove the magazine.", "partsFreed": [ "Magazine" ] }, { "n": 4, "instruction": "Pull the charging handle fully to the rear and lock the action open if the rifle has a hold-open." }, { "n": 5, "instruction": "Inspect the chamber and magazine well with a light, then physically confirm the chamber is empty.", "warning": "Look and feel. Both, every time." }, { "n": 6, "instruction": "Remove all live 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 selector on safe." }, { "n": 2, "instruction": "Push out the two push pins at the rear of the receiver and withdraw them.", "partsFreed": [ "Push pins" ] }, { "n": 3, "instruction": "Pull the buttstock straight back and off the rear of the receiver.", "warning": "The recoil spring assembly is under compression — control it.", "partsFreed": [ "Buttstock" ] }, { "n": 4, "instruction": "Pivot the trigger group down and off the receiver.", "partsFreed": [ "Trigger group" ] }, { "n": 5, "instruction": "Withdraw the recoil spring assembly from the rear of the receiver.", "partsFreed": [ "Recoil spring assembly" ] }, { "n": 6, "instruction": "Pull the cocking handle fully rearward and withdraw the bolt carrier group out of the rear of the receiver.", "partsFreed": [ "Bolt carrier group" ] }, { "n": 7, "instruction": "Separate the bolt head from the carrier, remove the locking piece, and push the rollers out of the bolt head from the inside.", "warning": "Keep the rollers and locking piece with their own bolt. Inspect the rollers for flats and chipping.", "partsFreed": [ "Bolt head", "Locking piece", "Rollers" ] }, { "n": 8, "instruction": "Remove the handguard by pushing out its retaining pin.", "partsFreed": [ "Handguard" ] } ] } ] }, { "id": "refinish", "title": "Refinish", "components": [ { "name": "Push pins", "procedure": "field-strip", "level": "field-strip", "step": 2 }, { "name": "Buttstock", "procedure": "field-strip", "level": "field-strip", "step": 3 }, { "name": "Trigger group", "procedure": "field-strip", "level": "field-strip", "step": 4 }, { "name": "Recoil spring assembly", "procedure": "field-strip", "level": "field-strip", "step": 5 }, { "name": "Bolt carrier group", "procedure": "field-strip", "level": "field-strip", "step": 6 }, { "name": "Bolt head", "procedure": "field-strip", "level": "field-strip", "step": 7 }, { "name": "Locking piece", "procedure": "field-strip", "level": "field-strip", "step": 7 }, { "name": "Rollers", "procedure": "field-strip", "level": "field-strip", "step": 7 }, { "name": "Handguard", "procedure": "field-strip", "level": "field-strip", "step": 8 } ], "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": "reassembly", "title": "Reassembly", "configuration": false, "steps": [ { "n": 1, "instruction": "Reinstall the handguard and its pin." }, { "n": 2, "instruction": "Reassemble the bolt: rollers into the bolt head, locking piece into the carrier, bolt head onto the carrier." }, { "n": 3, "instruction": "Insert the bolt carrier group into the rear of the receiver, engaging the cocking handle, and slide it forward." }, { "n": 4, "instruction": "Insert the recoil spring assembly into the rear of the receiver." }, { "n": 5, "instruction": "Pivot the trigger group into place and align its pin holes." }, { "n": 6, "instruction": "Slide the buttstock onto the rear of the receiver." }, { "n": 7, "instruction": "Insert both push pins and press them fully home.", "warning": "Both pins fully seated. A stock that is not pinned can come off under firing." }, { "n": 8, "instruction": "Pull the cocking handle fully back and release it sharply, then perform the function check." } ], "instruction": null } ] }, { "id": "torque", "title": "Torque", "coverage": "none-recorded", "manufacturer": [], "reported": [], "notes": "The manufacturer's documents give no torque value. They say: \"Once the correction has been completed, tighten the Phillips head rear sight clamping screw back down.\" (PTR Roller-Delayed Blowback Weapon Systems Owner's Manual, Models .308 and 7.62x39, PDF p. 10 (windage adjustment))" }, { "id": "function-check", "title": "Function check", "checks": [ "Verify the rifle is unloaded with no magazine inserted before each step.", "Pull the cocking handle fully rearward and release it sharply. The bolt should go fully into battery.", "With the selector on safe, press the trigger. The hammer must not fall.", "Move to semi-automatic, cock the action, and press the trigger. The hammer should fall.", "Hold the trigger back, cock the action, and release to feel the disconnector reset.", "Confirm both push pins are seated and the stock and trigger group are secure.", "If the bolt does not go fully into battery, do not fire. Have the bolt gap checked." ], "videos": [] } ], "troubleshooting": [], "sources": [ { "n": 1, "id": null, "title": "Heckler & Koch G3 Rifle Operator’s and Armorer’s Manual", "publisher": "Heckler & Koch GmbH", "reliability": "primary", "url": null, "accessed": null }, { "n": 2, "id": "ptr-industries-inc-99d501", "title": "PTR Roller-Delayed Blowback Weapon Systems Owner's Manual, Models .308 and 7.62x39", "publisher": "PTR Industries, Inc.", "reliability": "primary", "url": "https://www.ptr-us.com/wp-content/uploads/2023/01/PTR-.308-and-7.62x39-Owners-Manual.pdf", "accessed": "2026-09-27" }, { "n": 3, "id": "tier-0f62a3b6", "title": "MP-5 Armorers Instruction", "publisher": "Heckler & Koch, Inc. International Training Division", "reliability": "primary", "url": "https://archive.org/download/MManuals/HkMp5ArmorersManual.pdf", "accessed": "2026-10-29" }, { "n": 4, "id": "tier-f9206f76", "title": "G3 Armorer's Manual, Instructions for Maintenance and Repair, Cal. 7.62 mm x 51", "publisher": "Heckler & Koch", "reliability": "primary", "url": "https://archive.org/download/lots-of-gun-pdfs-firearms-manuals/Gun%20PDFs/hk_g3.pdf", "accessed": "2026-10-29" } ] }