{ "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": "ruger-ar-556", "name": "Ruger AR-556", "manufacturer": { "id": "ruger", "name": "Sturm, Ruger & Co." }, "category": "rifle", "action": "gas-operated-direct-impingement", "calibers": [ "5.56x45mm NATO", ".223 Remington" ], "alsoKnownAs": [ "AR-556 MPR" ], "coversAlso": [], "page": "firearms/ruger-ar-556.html", "bundle": "api/v1/firearms/ruger-ar-556.json", "lastUpdated": "2026-10-29" }, "notices": [ "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": "armorer-manual-verified" }, "manufacturerDisassembly": { "status": "published", "limit": null, "statement": null, "source": { "title": "Ruger AR-556 Owner’s Manual", "publisher": "Sturm, Ruger & Co., Inc.", "reliability": "primary", "url": "https://ruger-docs.s3.amazonaws.com/_manuals/AR-556.pdf", "page": "27", "pdfPage": 27, "pageUrl": "https://ruger-docs.s3.amazonaws.com/_manuals/AR-556.pdf#page=27", "quote": null } }, "recalls": [], "shopTier": { "tier": 2, "group": "rifle", "rating": "Pew-Takedown editorial rating (1 easy – 3 hardest), not the manufacturer's", "reason": "72 parts, the standard AR-15 full strip. It needs several captive detents and plungers (takedown and pivot detents, buffer retainer, selector detent, bolt catch plunger), roll pins, and a hammer spring that only works one way round. These are common traps with common jigs, and nothing is timed.", "confidence": "high", "partCount": { "value": 72, "kind": "line-items", "covers": "Complete rifle, standard handguard (72 line items; free-float supplement excluded)", "basis": "manufacturer-parts-list", "source": { "title": "Ruger AR-556 Owner’s Manual", "publisher": "Sturm, Ruger & Co., Inc.", "reliability": "primary", "url": "https://ruger-docs.s3.amazonaws.com/_manuals/AR-556.pdf", "page": "44–45", "pdfPage": 44, "pageUrl": "https://ruger-docs.s3.amazonaws.com/_manuals/AR-556.pdf#page=44", "quote": "72 Extractor" } }, "painPoints": [ { "issue": "The front pivot-pin detent and spring go in sideways under compression and launch across the room without a pivot-pin tool.", "during": "reassembly", "source": { "title": "DIY AR-15 Build: Pivot Pin Installation", "publisher": "ITS Tactical", "reliability": "secondary", "url": "https://www.itstactical.com/?p=10638", "page": null, "pdfPage": null, "pageUrl": null, "quote": "When inserting the detent that holds in the Pivot Pin, it’s quite common for it to turn into a Pegasus Missile and shoot across the room along with the spring that’s under tension." } }, { "issue": "A hammer spring fitted backwards can look right but will not detent the trigger pin. The result is light strikes and the pin walking out.", "during": "reassembly", "source": { "title": "(Gunsmithing the AR-15 #2) The 30-Second AR Check", "publisher": "Gun Tests", "reliability": "secondary", "url": "https://www.gun-tests.com/?p=26007", "page": null, "pdfPage": null, "pageUrl": null, "quote": "A hammer spring installed backwards will give a light primer strike causing misfires, and although it may appear to be laying on and detenting the trigger pin, it in fact will not." } } ], "minutes": { "strip": 45, "rebuild": 70, "basis": "estimated", "note": "Full AR strip: BCG, upper furniture and gas system, lower FCG, buffer, bolt catch, pivot/takedown detents. Rebuild time is driven by the detents and the roll pins.", "source": null }, "stripScope": [ { "assembly": "Upper", "removes": [ "handguard / delta ring or rail", "gas block and gas tube", "front sight (if fitted)", "flash hider", "forward assist", "ejection port cover and pin" ], "tools": [ "armorer's wrench" ] }, { "assembly": "Bolt carrier group", "removes": [ "firing pin retaining pin", "firing pin", "cam pin", "bolt", "extractor pin, extractor, spring", "ejector roll pin, ejector, spring" ] }, { "assembly": "Lower", "removes": [ "buffer, buffer spring, buffer retainer and spring", "castle nut / stock", "pistol grip (selector detent and spring)", "selector", "hammer, trigger, disconnector and springs", "bolt catch roll pin, bolt catch, plunger, spring", "magazine catch", "trigger guard roll pin", "front pivot pin and detent", "rear takedown pin and detent" ], "tools": [ "roll pin punches", "vise block" ] } ], "hardware": { "pins": 13, "springs": 12, "detents": 8, "basis": "counted from the manufacturer's parts list (one per key number unless a quantity is given)" }, "specialTools": [ { "tool": "AR armorer's wrench", "usedFor": "Castle nut, barrel/muzzle" }, { "tool": "upper and lower vise blocks", "usedFor": "Holding receivers" }, { "tool": "roll pin punches and starters (1/8, 3/32, 5/64 in)", "usedFor": "Bolt catch, trigger guard, gas block roll pins" }, { "tool": "pivot pin detent tool", "usedFor": "Front pivot pin detent" }, { "tool": "slave pin", "usedFor": "Trigger/hammer reassembly" } ], "fitOnRebuild": [ { "check": "Hammer spring orientation and pins flush", "why": "A reversed spring will not detent the trigger pin.", "source": { "title": "(Gunsmithing the AR-15 #2) The 30-Second AR Check", "publisher": "Gun Tests", "reliability": "secondary", "url": "https://www.gun-tests.com/?p=26007", "page": null, "pdfPage": null, "pageUrl": null, "quote": "Hammer spring is correctly installed with both legs horizontal, spread out against inside wall of receiver, and laying on top of trigger in properly in the at pin’s outboard groove, acting as a detent for same." } }, { "check": "Gas block alignment with port", "why": "A misaligned gas block short-strokes. Standard check.", "source": null }, { "check": "Function check (safety, trigger reset, feeding, extraction)", "why": "Standard after any detail strip. No single source.", "source": null }, { "check": "Re-zero sights or scope", "why": "Sights and optics come off for coating, and point of impact must be re-confirmed. This is a standard check, so no source.", "source": null } ], "assessed": "2026-10-29" }, "videos": [ { "title": "Ruger® AR-556® Disassembly Tech Tip", "url": "https://www.youtube.com/watch?v=qSiRy_QkHX8", "platform": "youtube", "embedUrl": null, "shows": [ "field-strip" ], "appliesTo": null, "published": "2015-06-10", "note": null, "channel": { "id": "UC9Ge9rpeTPQxnjlMH0VDwIA", "name": "RugerFirearms", "url": "https://www.youtube.com/@RugerFirearms", "owner": "Sturm, Ruger & Co., Inc." }, "accessed": "2026-10-15" }, { "title": "Ruger® AR-556® Reassembly Tech Tip", "url": "https://www.youtube.com/watch?v=o3grmup0Jms", "platform": "youtube", "embedUrl": null, "shows": [ "reassembly" ], "appliesTo": null, "published": "2015-06-10", "note": null, "channel": { "id": "UC9Ge9rpeTPQxnjlMH0VDwIA", "name": "RugerFirearms", "url": "https://www.youtube.com/@RugerFirearms", "owner": "Sturm, Ruger & Co., Inc." }, "accessed": "2026-10-15" }, { "title": "Ruger® AR-556® Cleaning Tech Tip", "url": "https://www.youtube.com/watch?v=hKuof-yI9Qo", "platform": "youtube", "embedUrl": null, "shows": [ "cleaning" ], "appliesTo": null, "published": "2015-06-09", "note": null, "channel": { "id": "UC9Ge9rpeTPQxnjlMH0VDwIA", "name": "RugerFirearms", "url": "https://www.youtube.com/@RugerFirearms", "owner": "Sturm, Ruger & Co., Inc." }, "accessed": "2026-10-15" }, { "title": "Ruger® AR-556® Delta Ring Tech Tip", "url": "https://www.youtube.com/watch?v=rxLnFn8UG-Y", "platform": "youtube", "embedUrl": null, "shows": [ "detail-strip" ], "appliesTo": null, "published": "2015-06-09", "note": null, "channel": { "id": "UC9Ge9rpeTPQxnjlMH0VDwIA", "name": "RugerFirearms", "url": "https://www.youtube.com/@RugerFirearms", "owner": "Sturm, Ruger & Co., Inc." }, "accessed": "2026-10-15" }, { "title": "Ruger® AR-556® MPR 450 Bushmaster Proper Magazine Alignment Tech Tip", "url": "https://www.youtube.com/watch?v=W0D-KJgXgWQ", "platform": "youtube", "embedUrl": null, "shows": [ "operation" ], "appliesTo": "Ruger AR-556 MPR in .450 Bushmaster (per description)", "published": "2021-11-22", "note": null, "channel": { "id": "UC9Ge9rpeTPQxnjlMH0VDwIA", "name": "RugerFirearms", "url": "https://www.youtube.com/@RugerFirearms", "owner": "Sturm, Ruger & Co., Inc." }, "accessed": "2026-10-15" } ], "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": "Press the magazine release and remove the magazine.", "partsFreed": [ "Magazine" ] }, { "n": 3, "instruction": "Pull the charging handle fully to the rear and lock the bolt back with the bolt catch." }, { "n": 4, "instruction": "Visually inspect the chamber and magazine well, then physically feel the chamber to confirm it is empty.", "warning": "Check the magazine well as well as the chamber — a round can hang up there." }, { "n": 5, "instruction": "If the hammer is cocked, place the selector on SAFE." }, { "n": 6, "instruction": "Remove all live ammunition from the work area." } ], "videos": [] }, { "id": "disassemble", "title": "Disassemble", "videos": [ { "title": "Ruger® AR-556® Disassembly Tech Tip", "url": "https://www.youtube.com/watch?v=qSiRy_QkHX8", "platform": "youtube", "embedUrl": null, "shows": [ "field-strip" ], "appliesTo": null, "published": "2015-06-10", "note": null, "channel": { "id": "UC9Ge9rpeTPQxnjlMH0VDwIA", "name": "RugerFirearms", "url": "https://www.youtube.com/@RugerFirearms", "owner": "Sturm, Ruger & Co., Inc." }, "accessed": "2026-10-15" }, { "title": "Ruger® AR-556® Delta Ring Tech Tip", "url": "https://www.youtube.com/watch?v=rxLnFn8UG-Y", "platform": "youtube", "embedUrl": null, "shows": [ "detail-strip" ], "appliesTo": null, "published": "2015-06-09", "note": null, "channel": { "id": "UC9Ge9rpeTPQxnjlMH0VDwIA", "name": "RugerFirearms", "url": "https://www.youtube.com/@RugerFirearms", "owner": "Sturm, Ruger & Co., Inc." }, "accessed": "2026-10-15" } ], "procedures": [ { "procedure": "field-strip", "title": "Field Strip", "level": "field-strip", "configuration": false, "steps": [ { "n": 1, "instruction": "Complete the Clear and Make Safe procedure and release the bolt forward." }, { "n": 2, "instruction": "From the left-hand side of the lower receiver, push the rear takedown pin to the right, then pull it from the right side until the detent stops further travel.", "warning": "Ruger's caution: the upper receiver will move forward once the pin is disengaged and can pinch your fingers if you are holding the magazine well. Hold the upper and lower together until you are ready to open the rifle.", "tip": "If the pin is stiff, Ruger sanctions using a punch and gently tapping with a hammer. It loosens with use." }, { "n": 3, "instruction": "Pivot the upper receiver forward on the front pivot pin.", "tip": "Tipping the upper forward on the front pivot pin is all Ruger's field strip requires. Driving the front pivot pin out as well fully separates the receivers, which is only needed to work on them separately." }, { "n": 4, "instruction": "Push the front pivot pin out to its captured position and separate the upper from the lower receiver.", "partsFreed": [ "Upper receiver assembly" ] }, { "n": 5, "instruction": "Pull the charging handle partway rearward and withdraw the bolt carrier group.", "partsFreed": [ "Bolt carrier group" ] }, { "n": 6, "instruction": "Pull the charging handle down and out of its channel.", "warning": "The charging handle comes out after the carrier, never before.", "partsFreed": [ "Charging handle" ] } ] } ] }, { "id": "refinish", "title": "Refinish", "components": [ { "name": "Upper receiver assembly", "procedure": "field-strip", "level": "field-strip", "step": 4 }, { "name": "Bolt carrier group", "procedure": "field-strip", "level": "field-strip", "step": 5 }, { "name": "Charging handle", "procedure": "field-strip", "level": "field-strip", "step": 6 } ], "manufacturerPartsList": { "parts": 72, "scope": "AR-556 (standard handguard); the manual's free-float handguard supplemental list is not included. Exploded views on pp. 46, 47 & 48" }, "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": [ { "title": "Ruger® AR-556® Reassembly Tech Tip", "url": "https://www.youtube.com/watch?v=o3grmup0Jms", "platform": "youtube", "embedUrl": null, "shows": [ "reassembly" ], "appliesTo": null, "published": "2015-06-10", "note": null, "channel": { "id": "UC9Ge9rpeTPQxnjlMH0VDwIA", "name": "RugerFirearms", "url": "https://www.youtube.com/@RugerFirearms", "owner": "Sturm, Ruger & Co., Inc." }, "accessed": "2026-10-15" } ], "procedures": [ { "procedure": "reassembly", "title": "Reassembly", "configuration": false, "steps": [ { "n": 1, "instruction": "Insert the bolt into the carrier with the extractor oriented toward the ejection port side." }, { "n": 2, "instruction": "Push the bolt fully into the carrier, drop the cam pin into its hole, and rotate it 90 degrees.", "warning": "If the cam pin is not rotated, the firing pin will not seat. Never force the firing pin." }, { "n": 3, "instruction": "Drop the firing pin into the rear of the carrier, tail first, and let it seat fully." }, { "n": 4, "instruction": "Install the firing pin retaining pin. If it will not go in, the cam pin is missing or not rotated.", "warning": "This is the design’s built-in check. Do not defeat it." }, { "n": 5, "instruction": "Insert the charging handle into its channel and push it partway forward." }, { "n": 6, "instruction": "Insert the bolt carrier group into the charging handle’s track and slide both fully home." }, { "n": 7, "instruction": "Mate the upper to the lower, press the front pivot pin home, close the receivers, and press the rear takedown pin home." }, { "n": 8, "instruction": "Charge the rifle and 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: \"Tighten the Delta Ring by turning it counterclockwise with your thumb and index finger (two-finger tight).\" (Ruger AR-556 Owner’s Manual, PDF p. 37) \"CAUTION: Do not over tighten the Delta Ring. Use two fingers only to tighten.\" (Ruger AR-556 Owner’s Manual, PDF p. 37)" }, { "id": "function-check", "title": "Function check", "checks": [ "Verify the rifle is unloaded with no magazine inserted before each step.", "Charge the rifle to cock the hammer, place the selector on SAFE, and press the trigger. The hammer must not fall.", "Move the selector to SEMI and press the trigger. The hammer should fall.", "Hold the trigger to the rear, charge the rifle, then release the trigger slowly and listen for the disconnector to release the hammer to the trigger.", "Press the trigger again. The hammer should fall.", "Insert an empty magazine, charge the rifle, and confirm the bolt locks back." ], "videos": [] } ], "troubleshooting": [ { "symptom": "The firing pin retaining pin will not go in.", "cause": "The cam pin is missing, or it is in but not rotated 90 degrees, so it blocks the retaining pin's hole.", "fix": "Pull the firing pin, seat the cam pin in its hole and rotate it a quarter turn, then reinstall the firing pin and the retaining pin.", "damageRisk": "Never force or trim the retaining pin. Without the cam pin rotated the bolt cannot lock, and the rifle is unsafe to fire." }, { "symptom": "The bolt carrier group will not slide back into the upper receiver.", "cause": "The charging handle is not in its channel ahead of the carrier, or the bolt is not pushed forward into its unlocked position on the carrier.", "fix": "Insert the charging handle part way, push the bolt fully forward in the carrier, then feed the carrier key into the charging handle's track and slide both home together." }, { "symptom": "The upper and lower will not close, or the rear takedown pin will not seat.", "cause": "The bolt carrier group is not fully forward in the upper, or the hammer is forward and fouling the carrier.", "fix": "Push the carrier fully into battery. If the receivers still will not close, cock the hammer before mating them.", "damageRisk": "Forcing the receivers shut on a hammer bends the disconnector and hammer hooks." }, { "symptom": "The takedown pins are extremely stiff on a new rifle.", "cause": "New receiver holes and detents are tight.", "fix": "Ruger's own instruction is to use a punch and gently tap the pin through. It becomes easier to remove over time." } ], "sources": [ { "n": 1, "id": null, "title": "TM 9-1005-319-10: Rifle, 5.56mm, M16A2/M4 Carbine", "publisher": "U.S. Department of the Army", "reliability": "primary", "url": null, "accessed": null }, { "n": 2, "id": "ruger-ar-556-manual", "title": "Ruger AR-556 Owner’s Manual", "publisher": "Sturm, Ruger & Co., Inc.", "reliability": "primary", "url": "https://ruger-docs.s3.amazonaws.com/_manuals/AR-556.pdf", "accessed": "2026-09-15" }, { "n": 3, "id": "tier-73313a6b", "title": "DIY AR-15 Build: Pivot Pin Installation", "publisher": "ITS Tactical", "reliability": "secondary", "url": "https://www.itstactical.com/?p=10638", "accessed": "2026-10-29" }, { "n": 4, "id": "tier-0310b242", "title": "(Gunsmithing the AR-15 #2) The 30-Second AR Check", "publisher": "Gun Tests", "reliability": "secondary", "url": "https://www.gun-tests.com/?p=26007", "accessed": "2026-10-29" } ] }