{ "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-usp", "name": "Heckler & Koch USP", "manufacturer": { "id": "heckler-koch", "name": "Heckler & Koch" }, "category": "pistol", "action": "hammer-fired-short-recoil", "calibers": [ "9x19mm Parabellum", ".40 S&W", ".45 ACP" ], "alsoKnownAs": [ "USP9", "USP40", "USP45", "USP Compact" ], "coversAlso": [ "USP Compact", "USP Tactical", "USP Expert", "HK45 (related design)" ], "page": "firearms/hk-usp.html", "bundle": "api/v1/firearms/hk-usp.json", "lastUpdated": "2026-10-29" }, "notices": [ "This work order is written for the Heckler & Koch USP. It is reported to cover USP Compact; USP Tactical; USP Expert; HK45 (related design) — if the firearm on the bench is one of those, check the torque notes: values do not always carry over.", "No manufacturer torque values are recorded. The values listed are reported by other sources, not the manufacturer — confirm them before use." ], "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": "published", "limit": null, "statement": null, "source": { "title": "Heckler & Koch USP Operator’s Manual", "publisher": "Heckler & Koch", "reliability": "primary", "url": "https://hk-usa.com/wp-content/uploads/2026/08/USP-Operators-Manual-8.25.2026-FINAL.pdf", "page": "27", "pdfPage": 27, "pageUrl": "https://hk-usa.com/wp-content/uploads/2026/08/USP-Operators-Manual-8.25.2026-FINAL.pdf#page=27", "quote": null } }, "recalls": [], "shopTier": { "tier": 2, "group": "pistol", "rating": "Pew-Takedown editorial rating (1 easy – 3 hardest), not the manufacturer's", "reason": "About 52 key numbers (91 pieces in HK's list counting variant rows) with several traps: the lanyard block is under spring tension, the control-lever detent plate is spring-loaded, the trigger-bar detent spring launches if the bar slips, and the disconnector is hard to get back in. Borderline Tier 3 for an LEM or variant-converted gun.", "confidence": "medium", "partCount": { "value": 54, "kind": "line-items", "covers": "USP full size, .40 S&W and 9 mm (incl. LEM sub-list) per this page's transcription; 89 rows, 54 distinct key numbers (highest 52). Compact, USP45 and Tactical/Expert lists omitted.", "basis": "manufacturer-parts-list", "source": { "title": "Heckler & Koch USP Operator’s Manual", "publisher": "Heckler & Koch", "reliability": "primary", "url": "https://hk-usa.com/wp-content/uploads/2026/08/USP-Operators-Manual-8.25.2026-FINAL.pdf", "page": "57", "pdfPage": 57, "pageUrl": "https://hk-usa.com/wp-content/uploads/2026/08/USP-Operators-Manual-8.25.2026-FINAL.pdf#page=57", "quote": "52 Magazine complete (10-rd, .40 cal.)" } }, "painPoints": [ { "issue": "The trigger-bar detent and its spring are held only by the trigger bar; if the bar slips while compressing it, the detent flies.", "during": "both", "source": { "title": "Detailed Disassembly of The Heckler & Koch USP (Dr. Killjoy, ed. Jeray)", "publisher": "hk-manuals archive (HK enthusiast write-up)", "reliability": "anecdotal", "url": "https://hk-manuals.s3.amazonaws.com/files/Armorer/USP/Detailed_Disassembly_of_the_HK_USP.pdf", "page": null, "pdfPage": null, "pageUrl": null, "quote": "If you let the trigger bar slip while it's compressing the detent spring, good luck finding the *&#$!!@$ thing on the floor : )" } }, { "issue": "The lanyard block holds the hammer spring under tension and comes out with it.", "during": "both", "source": { "title": "Detailed Disassembly of The Heckler & Koch USP (Dr. Killjoy, ed. Jeray)", "publisher": "hk-manuals archive (HK enthusiast write-up)", "reliability": "anecdotal", "url": "https://hk-manuals.s3.amazonaws.com/files/Armorer/USP/Detailed_Disassembly_of_the_HK_USP.pdf", "page": null, "pdfPage": null, "pageUrl": null, "quote": "Let the lanyard block out easy, it's under tension." } }, { "issue": "The control-lever detent plate is under spring pressure and goes airborne if its pin is pushed out carelessly.", "during": "both", "source": { "title": "Detailed Disassembly of The Heckler & Koch USP (Dr. Killjoy, ed. Jeray)", "publisher": "hk-manuals archive (HK enthusiast write-up)", "reliability": "anecdotal", "url": "https://hk-manuals.s3.amazonaws.com/files/Armorer/USP/Detailed_Disassembly_of_the_HK_USP.pdf", "page": null, "pdfPage": null, "pageUrl": null, "quote": "The plate is under slight spring pressure so don't let it go airborne." } }, { "issue": "A USP Compact owner lost the disconnector during a trigger conversion and describes it as nearly impossible to install correctly.", "during": "reassembly", "source": { "title": "Sigs vs HK's - Topic", "publisher": "SIGforum", "reliability": "anecdotal", "url": "https://sigforum.com/eve/forums/a/tpc/f/430601935/m/6900042305", "page": null, "pdfPage": null, "pageUrl": null, "quote": "Ended up losing the disconnect SOMEWHERE. It was only about impossible to install correctly anyway, so I suppose it serves it right to get lost." } } ], "minutes": { "strip": 35, "rebuild": 50, "basis": "estimated", "note": "Frame detail strip (lanyard block, hammer spring, detent plate, control lever, sear/catch/disconnector, trigger bar and detent, hammer, trigger) plus slide; rebuild longer for the detent spring and disconnector.", "source": null }, "stripScope": [ { "assembly": "Slide", "removes": [ "firing pin and spring", "firing pin block", "extractor", "rear sight", "front sight" ], "tools": [ "roll-pin punches", "sight pusher" ] }, { "assembly": "Frame", "removes": [ "lanyard block / hammer spring", "control lever and detent plate", "disconnector, catch, sear", "trigger bar, detent and flat spring", "hammer and strut", "trigger and pivot pin", "slide release" ], "tools": [ "tweezers", "plastic pick", "HK trigger return spring pliers" ] } ], "hardware": { "pins": 11, "springs": 13, "detents": 5, "basis": "counted from the manufacturer's parts list (one per key number unless a quantity is given)" }, "specialTools": [ { "tool": "HK trigger return spring pliers", "usedFor": "Trigger rebound/return spring" }, { "tool": "tweezers and a plastic pick", "usedFor": "Detent plate, trigger bar detent and flat spring (per the enthusiast guide)" }, { "tool": "dovetail sight pusher (or brass drift and padded vise)", "usedFor": "Removing and refitting dovetailed sights for coating" } ], "fitOnRebuild": [ { "check": "Control-lever variant parts match", "why": "USP variants (1-10) and the 2005 catch/hammer revision use different detent plates and catches; mixed parts will not function", "source": { "title": "Heckler & Koch USP Operator’s Manual", "publisher": "Heckler & Koch", "reliability": "primary", "url": "https://hk-usa.com/wp-content/uploads/2026/08/USP-Operators-Manual-8.25.2026-FINAL.pdf", "page": null, "pdfPage": null, "pageUrl": null, "quote": "In 2005, the USP catch was modified to fit the revised USP hammer." } }, { "check": "Function check: trigger reset, sear/striker engagement, safeties", "why": "Standard post-reassembly check on any pistol whose fire-control parts were removed; a mis-seated spring shows up here, not on the bench", "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": "Remove the magazine.", "warning": "A cartridge can be in the chamber whether or not a magazine is fitted, and will fire if the trigger is pulled." }, { "n": 3, "instruction": "Retract and lock the slide fully to the rear." }, { "n": 4, "instruction": "Visually AND physically check with your finger that there is no cartridge in the chamber.", "warning": "HK's instruction: never rely solely on a mechanical device or your memory to decide whether the pistol is loaded." }, { "n": 5, "instruction": "Unload all magazines and remove all live ammunition from the 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 clearing and safety check." }, { "n": 2, "instruction": "Depress the slide release and allow the slide to move forward." }, { "n": 3, "instruction": "Hold the pistol so your thumb covers the rear of the frame and your fingers rest on top of the slide." }, { "n": 4, "instruction": "With the firing hand, pull the slide back until the retention tab of the slide release is visible through the recess on the left side of the slide.", "tip": "That recess, not a takedown notch, is the index." }, { "n": 5, "instruction": "With the other hand, press on the axle of the slide release from the RIGHT side of the frame and remove the slide release completely from the LEFT side.", "partsFreed": [ "Slide release" ] }, { "n": 6, "instruction": "Holding the recoil assembly in place, slide the slide with barrel and recoil spring assembly forward off the frame.", "warning": "Keep hold of the recoil assembly. Released under spring tension it can injure someone or be lost.", "partsFreed": [ "Slide assembly" ] }, { "n": 7, "instruction": "Turn the slide upside down and carefully push the recoil spring forward, up, and out to either the left or right side, separating it from the barrel and slide.", "warning": "The recoil spring assembly is captive. HK does not recommend disassembling it further.", "partsFreed": [ "Recoil spring assembly" ] }, { "n": 8, "instruction": "Pivot the barrel slightly forward and press upward on the barrel through the ejection port to separate it from the slide.", "partsFreed": [ "Barrel" ] }, { "n": 9, "instruction": "Stop here.", "warning": "HK states that only a certified HK armorer should disassemble the pistol further." } ] } ] }, { "id": "refinish", "title": "Refinish", "components": [ { "name": "Slide release", "procedure": "field-strip", "level": "field-strip", "step": 5 }, { "name": "Slide assembly", "procedure": "field-strip", "level": "field-strip", "step": 6 }, { "name": "Recoil spring assembly", "procedure": "field-strip", "level": "field-strip", "step": 7 }, { "name": "Barrel", "procedure": "field-strip", "level": "field-strip", "step": 8 } ], "manufacturerPartsList": { "parts": 89, "scope": "USP full size, .40 S&W and 9 mm (incl. LEM USP Full Size sub-list). Omitted: USP45 (p.59), USP Compact .40/9mm (p.61), USP Compact .45 (p.63), and Tactical/Expert/45 Elite lists (p.64). Exploded view p.56." }, "partsDiagrams": [], "materials": [ { "component": "Frame", "material": "polymer", "finish": null, "appliesTo": "all USP models", "note": null, "source": { "title": "Heckler & Koch USP Operator’s Manual", "publisher": "Heckler & Koch", "reliability": "primary", "url": "https://hk-usa.com/wp-content/uploads/2026/08/USP-Operators-Manual-8.25.2026-FINAL.pdf", "page": null, "pdfPage": null, "pageUrl": null, "quote": "A set of mounting grooves for installing accessories is molded in the polymer frame of all USP models." } } ], "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": "Position the barrel in the slide so the muzzle fits the hole in the front of the slide, and the locking block sits within the ejection port with its angled locking surfaces visible along the bottom of the slide." }, { "n": 2, "instruction": "Install the recoil spring assembly so the front of the recoil spring guide rod engages the small hole in the front of the slide." }, { "n": 3, "instruction": "Align the opposing angled locking surfaces on the rear end of the recoil spring guide rod with those on the bottom of the barrel locking block.", "tip": "This alignment is the whole trick to USP reassembly." }, { "n": 4, "instruction": "Push the rear of the recoil spring assembly forward far enough that the recoil spring retainer engages the shelf on the front of the barrel locking block." }, { "n": 5, "instruction": "Hold the slide in the non-firing hand with your thumb keeping the rear of the recoil spring assembly in place." }, { "n": 6, "instruction": "Check the position of the sear axle on the frame and make sure it does not protrude from either side.", "warning": "A proud sear axle will stop the slide going on, and is easy to miss." }, { "n": 7, "instruction": "Hold the frame in the firing hand and position the rear of the slide above the front edge of the frame." }, { "n": 8, "instruction": "Slowly draw the slide back onto the frame, pressing down on the disconnector with the rear of the slide so the metal inserts in the frame enter the grooves inside the slide." }, { "n": 9, "instruction": "Retract the slide until the recess on its left side sits over the slide release axle hole, and hold it there." }, { "n": 10, "instruction": "Insert the slide release from left to right into the frame until it is flush with the side of the frame." }, { "n": 11, "instruction": "Clear the pistol and check it for correct assembly and operation.", "warning": "HK requires a function check every time the pistol has been disassembled. Match it to your control variant." } ], "instruction": null } ] }, { "id": "torque", "title": "Torque", "coverage": "reported-only", "manufacturer": [], "reported": [ { "fastener": "Red-dot optic mounting screws (6-32 flat head, supplied) into EGW rear-dovetail sight mount", "appliesTo": "HK USP / USP Tactical 9mm, .40, .45 (not USP Compact, Expert, Elite) with the EGW 'Trijicon RMR / SRO, Holosun 407c / 507c Mount for HK USP' (replaces the rear sight; for Trijicon RMR/SRO, Holosun 407", "qualifier": "exact", "value": 15, "valueMax": null, "unit": "in-lb", "converted": { "value": { "N-m": 1.7, "in-lb": 15, "ft-lb": 1.2 }, "valueMax": null }, "sequence": "Remove the rear sight, install the EGW mount in the dovetail, tighten the set screw if applicable, place the optic on the mount, then apply blue Loctite and torque the optic screws.", "threadlocker": "Blue Loctite on the provided mounting screws (EGW instructions)", "source": { "title": "Trijicon RMR / SRO, Holosun 407c / 507c Mount for HK USP (EGW product page, installation instructions section)", "publisher": "Evolution Gun Works (EGW)", "reliability": "secondary", "url": "https://egwguns.com/trijicon-rmr-sro-holosun-407c-507c-mount-for-h-k-usp", "page": null, "pdfPage": null, "pageUrl": null, "quote": "Torque mounting screws to 15in/lbs" } }, { "fastener": "Red-dot optic mounting screws (supplied) into EGW rear-dovetail sight mount (Docter/Venom/Viper/FastFire footprint)", "appliesTo": "HK USP / USP Tactical 9mm, .40, .45 (not USP Compact, Expert, Elite) with the EGW 'HK USP Red Dot Mount | Fits Vortex Venom & Burris FastFire' (replaces the rear sight)", "qualifier": "exact", "value": 15, "valueMax": null, "unit": "in-lb", "converted": { "value": { "N-m": 1.7, "in-lb": 15, "ft-lb": 1.2 }, "valueMax": null }, "sequence": "Remove the rear sight, install the EGW mount in the dovetail, tighten the set screw if applicable, place the optic on the mount, then apply blue Loctite and torque the optic screws.", "threadlocker": "Blue Loctite on the provided mounting screws (EGW instructions)", "source": { "title": "HK USP Red Dot Mount | Fits Vortex Venom & Burris FastFire (EGW product page, installation instructions section)", "publisher": "Evolution Gun Works (EGW)", "reliability": "secondary", "url": "https://egwguns.com/vortex-viper-venom-hk-usp-sight-mount-fits-burris-fastfire-and-docter", "page": null, "pdfPage": null, "pageUrl": null, "quote": "Torque mounting screws to 15 in/lbs" } } ], "notes": "The manufacturer's documents give no torque value. They say: \"DO NOT OVER TIGHTEN THREAD PROTECTORS.\" (Heckler & Koch USP Operator’s Manual, PDF p. 9 (\"Instructions for use of HK thread protectors\")) \"Secure the bases by tightening the two 3 mm Allen screws on the right side of the frame, DO NOT OVERTIGHTEN (see figure 35 & 36).\" (USP Operator's Manual (3_1_21), p. USP Match counterweight section)" }, { "id": "function-check", "title": "Function check", "checks": [ "Verify the pistol is unloaded with no magazine inserted before each check.", "With the hammer down, press the trigger for a double-action hammer fall (on DA/SA variants).", "Cock the hammer, engage the safety or decocker as fitted, and confirm the expected behaviour: a safety must block the trigger; a decocker must lower the hammer without the firing pin being struck.", "Rack the slide and press the trigger for a single-action break.", "Hold the trigger back, rack the slide, release slowly and confirm the reset.", "Confirm the slide locks open on an empty magazine." ], "videos": [] } ], "troubleshooting": [ { "symptom": "The recoil spring assembly will not stay in the slide, or springs back out while fitting the barrel.", "cause": "The angled locking surfaces on the rear of the guide rod are not aligned with those on the bottom of the barrel locking block, so the recoil spring retainer never engages its shelf.", "fix": "Seat the guide rod's front in the hole at the front of the slide, line up the opposing angled surfaces, then push the rear of the assembly forward until the retainer catches the shelf on the front of the locking block.", "damageRisk": "Levering the assembly in against the barrel bends the guide rod." }, { "symptom": "The slide will not go back onto the frame.", "cause": "The sear axle is protruding from the side of the frame, or the rear of the slide is not pressing the disconnector down.", "fix": "Check the sear axle is flush on both sides of the frame, then set the rear of the slide above the front edge of the frame and draw it back slowly so it presses the disconnector down as the frame inserts enter the slide grooves.", "damageRisk": "Forcing the slide over a proud sear axle shears it." }, { "symptom": "The slide release will not go back in.", "cause": "The slide is not held at the point where the recess on its left side sits over the axle hole.", "fix": "Retract the slide until the recess lines up with the hole, hold it there, and insert the slide release from left to right until flush." }, { "symptom": "A compact USP feels wrong after reassembly, or the slide short-cycles.", "cause": "The USP9 Compact and USP40 Compact recoil springs have been swapped.", "fix": "The USP9 Compact spring is coloured red. Fit the one that belongs to the calibre." } ], "sources": [ { "n": 1, "id": "hk-usp-manual", "title": "Heckler & Koch USP Operator’s Manual", "publisher": "Heckler & Koch", "reliability": "primary", "url": "https://hk-usa.com/wp-content/uploads/2026/08/USP-Operators-Manual-8.25.2026-FINAL.pdf", "accessed": "2026-09-15" }, { "n": 2, "id": "heckler-koch-usa-heckler-koch-inc-c57c15", "title": "USP Operator's Manual (3_1_21)", "publisher": "Heckler & Koch USA (Heckler & Koch, Inc.)", "reliability": "primary", "url": "https://hk-usa.com/wp-content/uploads/2023/09/USP-Operators-Manual-3_1_21-1.pdf", "accessed": "2026-09-27" }, { "n": 3, "id": "evolution-gun-works-egw-903259", "title": "Trijicon RMR / SRO, Holosun 407c / 507c Mount for HK USP (EGW product page, installation instructions section)", "publisher": "Evolution Gun Works (EGW)", "reliability": "secondary", "url": "https://egwguns.com/trijicon-rmr-sro-holosun-407c-507c-mount-for-h-k-usp", "accessed": "2026-10-11" }, { "n": 4, "id": "evolution-gun-works-egw-0f830c", "title": "HK USP Red Dot Mount | Fits Vortex Venom & Burris FastFire (EGW product page, installation instructions section)", "publisher": "Evolution Gun Works (EGW)", "reliability": "secondary", "url": "https://egwguns.com/vortex-viper-venom-hk-usp-sight-mount-fits-burris-fastfire-and-docter", "accessed": "2026-10-11" }, { "n": 5, "id": "tier-e7087083", "title": "Detailed Disassembly of The Heckler & Koch USP (Dr. Killjoy, ed. Jeray)", "publisher": "hk-manuals archive (HK enthusiast write-up)", "reliability": "anecdotal", "url": "https://hk-manuals.s3.amazonaws.com/files/Armorer/USP/Detailed_Disassembly_of_the_HK_USP.pdf", "accessed": "2026-10-29" }, { "n": 6, "id": "tier-9aca1ea3", "title": "Sigs vs HK's - Topic", "publisher": "SIGforum", "reliability": "anecdotal", "url": "https://sigforum.com/eve/forums/a/tpc/f/430601935/m/6900042305", "accessed": "2026-10-29" } ] }