{ "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": "sig-mcx", "name": "SIG Sauer MCX", "manufacturer": { "id": "sig-sauer", "name": "SIG Sauer" }, "category": "rifle", "action": "gas-operated-short-stroke", "calibers": [ "5.56x45mm NATO", ".300 AAC Blackout", "7.62x39mm" ], "alsoKnownAs": [ "MCX Virtus", "MCX Spear LT", "MCX Rattler" ], "coversAlso": [ "MCX Virtus", "MCX Spear LT", "MCX Rattler (with differences)" ], "page": "firearms/sig-mcx.html", "bundle": "api/v1/firearms/sig-mcx.json", "lastUpdated": "2026-10-29" }, "notices": [ "SIG Sauer limits owner disassembly: Field strip (receivers apart, recoil assembly and charging handle out, bolt carrier stripped to bolt, cam pin, firing pin and extractor), gas piston and barrel removal per section 4.1.", "This work order is written for the SIG Sauer MCX. It is reported to cover MCX Virtus; MCX Spear LT; MCX Rattler (with differences) — if the firearm on the bench is one of those, check the torque notes: values do not always carry over." ], "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": "community-reviewed" }, "manufacturerDisassembly": { "status": "limited", "limit": "Field strip (receivers apart, recoil assembly and charging handle out, bolt carrier stripped to bolt, cam pin, firing pin and extractor), gas piston and barrel removal per section 4.1.", "statement": "SIG says not to disassemble the MCX beyond the point explained in the manual; anything further is restricted to a certified SIG SAUER armorer or professional gunsmith, and ignoring this voids the warranty. The field-strip section ends 'No further disassembly is authorized.'", "source": { "title": "SIG MCX VIRTUS Operator's Manual: Handling & Safety Instructions (2402117-01 REV 00)", "publisher": "SIG SAUER, Inc.", "reliability": "primary", "url": "https://www.sigsauer.com/pub/media/sigsauer/resources/OPERATORS-MANUAL-SIGMCX-VIRTUS-ENGLISH-2402117-01-REV-00-LR.pdf", "page": "6", "pdfPage": 6, "pageUrl": "https://www.sigsauer.com/pub/media/sigsauer/resources/OPERATORS-MANUAL-SIGMCX-VIRTUS-ENGLISH-2402117-01-REV-00-LR.pdf#page=6", "quote": "Do not attempt to disassemble your SIG SAUER firearm beyond the point explained in this manual. Disassembly beyond the instructions in this manual is restricted to a certified SIG SAUER Armorer or Professional Gunsmith. Failure to comply with these restrictions will void your warranty." } }, "recalls": [], "shopTier": { "tier": 2, "group": "rifle", "rating": "Pew-Takedown editorial rating (1 easy – 3 hardest), not the manufacturer's", "reason": "The upper is simpler than an AR, with no buffer tube and a captive dual recoil-spring op rod. The lower carries an AR-pattern fire-control group and its detents. SIG reserves anything past user level for armorers, so the full strip has the same traps as the AR, which makes it Tier 2.", "confidence": "medium", "partCount": { "value": 28, "kind": "line-items", "covers": "ASSEMBLY-LEVEL only: MCX VIRTUS upper and lower receiver assembly parts lists (sub-assemblies, not small parts)", "basis": "manufacturer-parts-list", "source": { "title": "SIG MCX VIRTUS Operator's Manual: Handling & Safety Instructions (2402117-01 REV 00)", "publisher": "SIG SAUER, Inc.", "reliability": "primary", "url": "https://www.sigsauer.com/pub/media/sigsauer/resources/OPERATORS-MANUAL-SIGMCX-VIRTUS-ENGLISH-2402117-01-REV-00-LR.pdf", "page": "82–84", "pdfPage": 82, "pageUrl": "https://www.sigsauer.com/pub/media/sigsauer/resources/OPERATORS-MANUAL-SIGMCX-VIRTUS-ENGLISH-2402117-01-REV-00-LR.pdf#page=82", "quote": "4 Pivoting Contour Brace" } }, "painPoints": [ { "issue": "The bolt carrier and op-rod springs are under load and fly forward if the bolt catch is touched while the group is out.", "during": "both", "source": { "title": "SIG MCX VIRTUS Operator's Manual: Handling & Safety Instructions (2402117-01 REV 00)", "publisher": "SIG SAUER, Inc.", "reliability": "primary", "url": "https://www.sigsauer.com/pub/media/sigsauer/resources/OPERATORS-MANUAL-SIGMCX-VIRTUS-ENGLISH-2402117-01-REV-00-LR.pdf", "page": null, "pdfPage": null, "pageUrl": null, "quote": "THE BOLT CARRIER ASSEMBLY IS UNDER SPRING TENSION AND WILL SPRING FORWARD IF THE BOLT CATCH IS INADVERTENTLY DEPRESSED POSSIBLY CAUSING INJURY." } }, { "issue": "SIG gives no owner procedure beyond the bolt and extractor. Lower and fire-control detail strip is armorer-level (SIG MCX Technical Armorer's Manual).", "during": "both", "source": { "title": "SIG MCX VIRTUS Operator's Manual: Handling & Safety Instructions (2402117-01 REV 00)", "publisher": "SIG SAUER, Inc.", "reliability": "primary", "url": "https://www.sigsauer.com/pub/media/sigsauer/resources/OPERATORS-MANUAL-SIGMCX-VIRTUS-ENGLISH-2402117-01-REV-00-LR.pdf", "page": null, "pdfPage": null, "pageUrl": null, "quote": "Disassembly beyond the instructions in this manual is restricted to a certified SIG SAUER Armorer or Professional Gunsmith." } }, { "issue": "The AR-pattern hammer spring in the lower can be fitted backwards and fail to detent the trigger pin.", "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": 40, "rebuild": 60, "basis": "estimated", "note": "Upper (BCG, op rod and recoil springs, handguard, gas system), lower AR-pattern FCG, detents.", "source": null }, "stripScope": [ { "assembly": "Upper", "removes": [ "handguard", "BCG and dual recoil-spring op rod", "charging handle", "gas block/piston (armorer level)" ] }, { "assembly": "Bolt", "removes": [ "firing pin, cam pin, bolt", "extractor" ] }, { "assembly": "Lower", "removes": [ "fire-control group", "selector and detent", "bolt catch", "magazine release", "takedown/pivot pins and detents", "brace/stock" ] } ], "hardware": { "pins": 5, "springs": 1, "detents": 0, "basis": "counted from the manufacturer's parts list (one per key number unless a quantity is given)" }, "specialTools": [ { "tool": "roll pin punches", "usedFor": "Lower parts" }, { "tool": "pivot pin detent tool", "usedFor": "Pivot pin detent" }, { "tool": "SIG armorer tools", "usedFor": "Anything past user level (see MCX Technical Armorer's Manual)" } ], "fitOnRebuild": [ { "check": "Hammer spring orientation", "why": "AR-pattern FCG.", "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": "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": "Tactical Tip: Changing Barrels MCX VIRTUS", "url": "https://www.youtube.com/watch?v=BQGj3j4Nvw8", "platform": "youtube", "embedUrl": null, "shows": [ "maintenance" ], "appliesTo": "MCX VIRTUS (per the title)", "published": "2017-11-30", "note": null, "channel": { "id": "UCvoH9K7l8MTVs6NO6KybLUA", "name": "SIG SAUER Academy", "url": "https://www.youtube.com/@SIGSAUERACDY", "owner": "SIG SAUER Academy (SIG SAUER, Inc. training division; site footer '© SIG SAUER 2026', logins via auth.sigsauer.com)" }, "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": "Place the selector on safe." }, { "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 bolt back 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 and release the bolt forward." }, { "n": 2, "instruction": "Push out the rear takedown pin and pivot the upper receiver open on the front pivot pin.", "partsFreed": [ "Rear takedown pin" ] }, { "n": 3, "instruction": "Push out the front pivot pin and separate the upper from the lower receiver.", "partsFreed": [ "Upper receiver assembly" ] }, { "n": 4, "instruction": "Pull the charging handle rearward and withdraw the bolt carrier group and recoil spring assembly out of the upper.", "warning": "The dual recoil springs are under compression.", "partsFreed": [ "Bolt carrier group", "Recoil spring assembly" ] }, { "n": 5, "instruction": "Remove the firing pin retaining pin, tip out the firing pin, rotate and lift the cam pin, and withdraw the bolt.", "warning": "Keep the cam pin with the rifle.", "partsFreed": [ "Firing pin", "Cam pin", "Bolt" ] }, { "n": 6, "instruction": "Withdraw the gas piston from its cylinder, noting orientation.", "partsFreed": [ "Gas piston" ] } ] } ] }, { "id": "refinish", "title": "Refinish", "components": [ { "name": "Rear takedown pin", "procedure": "field-strip", "level": "field-strip", "step": 2 }, { "name": "Upper receiver assembly", "procedure": "field-strip", "level": "field-strip", "step": 3 }, { "name": "Bolt carrier group", "procedure": "field-strip", "level": "field-strip", "step": 4 }, { "name": "Recoil spring assembly", "procedure": "field-strip", "level": "field-strip", "step": 4 }, { "name": "Firing pin", "procedure": "field-strip", "level": "field-strip", "step": 5 }, { "name": "Cam pin", "procedure": "field-strip", "level": "field-strip", "step": 5 }, { "name": "Bolt", "procedure": "field-strip", "level": "field-strip", "step": 5 }, { "name": "Gas piston", "procedure": "field-strip", "level": "field-strip", "step": 6 } ], "manufacturerPartsList": { "parts": 28, "scope": "MCX VIRTUS 'Upper Receiver Assembly Parts List' (5.8, p.83) and 'Lower Receiver Assembly Parts List' (5.10, p.84) with diagrams. Earlier MCX (first-gen) and MCX-SPEAR LT manuals' lists were not used." }, "partsDiagrams": [], "materials": [ { "component": "Handguard", "material": "aluminum", "finish": null, "appliesTo": "SIG MCX (manual covers 5.56 NATO / 300 BLK rifle, SBR, pistol)", "note": null, "source": { "title": "SIG MCX Owners Manual: Handling & Safety Instructions", "publisher": "SIG SAUER, Inc.", "reliability": "primary", "url": "https://www.sigsauer.com/media/sigsauer/resources/MCX.pdf", "page": null, "pdfPage": null, "pageUrl": null, "quote": "The MCX is fitted with an aluminum handguard which provides KeyMod mounting interfaces for accessories at the 3-6-9 clock positions." } }, { "component": "Receiver (upper/lower)", "material": "ALUMINUM", "finish": null, "appliesTo": "SIG MCX", "note": null, "source": { "title": "SIG MCX Owners Manual: Handling & Safety Instructions", "publisher": "SIG SAUER, Inc.", "reliability": "primary", "url": "https://www.sigsauer.com/media/sigsauer/resources/MCX.pdf", "page": null, "pdfPage": null, "pageUrl": null, "quote": "DO NOT USE WIRE BRUSHES ON ALUMINUM SURFACES SUCH AS THE UPPER/LOWER RECEIVERS AS THIS CAN SCRATCH THE FINISH." } } ], "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 gas piston in its correct orientation." }, { "n": 2, "instruction": "Fit the bolt into the carrier, install and rotate the cam pin, then the firing pin and its retaining pin." }, { "n": 3, "instruction": "Insert the bolt carrier group and recoil spring assembly into the upper receiver and seat them." }, { "n": 4, "instruction": "Mate the upper to the lower receiver and press both pins home." }, { "n": 5, "instruction": "Cycle the action several times and perform the function check." } ], "instruction": null } ] }, { "id": "torque", "title": "Torque", "coverage": "sourced", "manufacturer": [ { "fastener": "Barrel clamp screws #1 and #2 (T27 Torx)", "appliesTo": "SIG MCX (first-generation MCX owner's manual)", "qualifier": "exact", "value": 60, "valueMax": null, "unit": "in-lb", "converted": { "value": { "N-m": 6.8, "in-lb": 60, "ft-lb": 5 }, "valueMax": null }, "sequence": "Start tightening screw #1 with the T-27 Torx wrench, alternating between screw #1 and screw #2 with even pressure until the barrel clamps are snug; then 60 in-lb on #1, 60 in-lb on #2, and re-tighten #1 to 60 in-lb. Check the barrel index pins first and make sure all mating surfaces are clean.", "threadlocker": null, "source": { "title": "SIG MCX Owners Manual: Handling & Safety Instructions", "publisher": "SIG SAUER, Inc.", "reliability": "primary", "url": "https://www.sigsauer.com/media/sigsauer/resources/MCX.pdf", "page": "PDF p. 64 (section 4.1.5 Barrel Installa", "pdfPage": 64, "pageUrl": "https://www.sigsauer.com/media/sigsauer/resources/MCX.pdf#page=64", "quote": "Tighten screw #1, to 60 inch pounds with a torque wrench. Then tighten screw #2 to 60 inch pounds. Final step is to re-tighten screw #1 to 60 inch pounds." } }, { "fastener": "Barrel clamp screws #1 and #2 (T-27 Torx)", "appliesTo": "SIG MCX VIRTUS (rifle, patrol, pistol variants)", "qualifier": "exact", "value": 60, "valueMax": null, "unit": "in-lb", "converted": { "value": { "N-m": 6.8, "in-lb": 60, "ft-lb": 5 }, "valueMax": null }, "sequence": "Start tightening screw #1 with the T-27 Torx wrench, alternating between screw #1 and screw #2 with even pressure until the barrel clamps are snug; then 60 in-lb on #1, 60 in-lb on #2, and re-tighten #1 to 60 in-lb. Check the barrel index pins first and make sure all mating surfaces are clean.", "threadlocker": null, "source": { "title": "SIG MCX VIRTUS Operator's Manual: Handling & Safety Instructions (2402117-01 REV 00)", "publisher": "SIG SAUER, Inc.", "reliability": "primary", "url": "https://www.sigsauer.com/pub/media/sigsauer/resources/OPERATORS-MANUAL-SIGMCX-VIRTUS-ENGLISH-2402117-01-REV-00-LR.pdf", "page": "PDF p. 64 (section 4.1.5 Barrel Installa", "pdfPage": 64, "pageUrl": "https://www.sigsauer.com/pub/media/sigsauer/resources/OPERATORS-MANUAL-SIGMCX-VIRTUS-ENGLISH-2402117-01-REV-00-LR.pdf#page=64", "quote": "Tighten screw #1, to 60 inch pounds with a torque wrench. Then tighten screw #2 to 60 inch pounds. Last step is to re-tighten screw #1 to 60 inch pounds." } }, { "fastener": "Barrel clamp screws #1 and #2 (T27 Torx)", "appliesTo": "SIG MCX-SPEAR LT", "qualifier": "exact", "value": 60, "valueMax": null, "unit": "in-lb", "converted": { "value": { "N-m": 6.8, "in-lb": 60, "ft-lb": 5 }, "valueMax": null }, "sequence": "Seat both index pins completely; pinch the left and right clamp together until they contact the upper receiver; with a T27 Torx wrench tighten alternately between screw #1 and #2 until just hand tight; then 60 lb-in on #1, 60 lb-in on #2, and #1 again.", "threadlocker": null, "source": { "title": "SIG MCX-SPEAR LT Operator's Manual: Handling & Safety Instructions (2402988-01 REV00)", "publisher": "SIG SAUER, Inc.", "reliability": "primary", "url": "https://www.sigsauer.com/media/sigsauer/resources/OPERATORS-MANUAL-MCX-SPEAR-LT-2402988-01-REV00-WEB-FILE.pdf", "page": "PDF p. 70 (section 4.7 Barrel Installati", "pdfPage": 70, "pageUrl": "https://www.sigsauer.com/media/sigsauer/resources/OPERATORS-MANUAL-MCX-SPEAR-LT-2402988-01-REV00-WEB-FILE.pdf#page=70", "quote": "Start with screw #1 and apply a torque of 60 lb-in. Move to screw #2 and apply torque of 60 lb-in. Return to screw #1 and tighten again to ensure that the screw is at 60 lb-in." } } ], "reported": [ { "fastener": "Barrel screws", "appliesTo": "SIG Sauer MCX", "qualifier": "exact", "value": 60, "valueMax": null, "unit": "in-lb", "converted": { "value": { "N-m": 6.8, "in-lb": 60, "ft-lb": 5 }, "valueMax": null }, "sequence": null, "threadlocker": null, "source": { "title": "Torque Specs (Torque Specs by Brand — Sig Sauer MCX)", "publisher": "Fix It Sticks (compiled reference list)", "reliability": "tertiary", "url": "https://store.fixitsticks.com/pages/torque-specs", "page": null, "pdfPage": null, "pageUrl": null, "quote": "Barrel Screws: 60 in-lbs" } }, { "fastener": "Arisaka Zero Retention Clamp screws (left/right clamps to the U-bracket)", "appliesTo": "SIG MCX Virtus (5.56 or 300BLK) with SIG Standard, SIG SD Suppressor, MI Standard or MI Suppressor handguard and an Arisaka ZRC", "qualifier": "exact", "value": 20, "valueMax": null, "unit": "in-lb", "converted": { "value": { "N-m": 2.3, "in-lb": 20, "ft-lb": 1.7 }, "valueMax": null }, "sequence": "Reinstall the handguard first; alternate tightening the clamps, finger tight, then torque.", "threadlocker": null, "source": { "title": "Arisaka Zero Retention Clamp — MCX Virtus (SIG Standard / SIG SD Suppressor / MI Standard / MI Suppressor handguards), dated 07/25/2023 (ArisakaZRC-Virtus-03)", "publisher": "Arisaka Defense", "reliability": "secondary", "url": "https://arisakadefense.com/content/ArisakaZRC-Virtus-03.pdf", "page": "PDF p. 3, step 6", "pdfPage": 3, "pageUrl": "https://arisakadefense.com/content/ArisakaZRC-Virtus-03.pdf#page=3", "quote": "Alternate tightening the clamps in place. Once finger tight, torque to 20 inch lbs." } } ], "notes": "The manufacturer's documents give no torque value. They say: \"Reinstall the clamp and tighten the screw snug plus ¼ turn.\" (SIG MCX Owners Manual: Handling & Safety Instructions, PDF p. 54 (Collapsible Stock Installation/Removal)) \"Tighten the screw until snug plus 1/4 turn.\" (SIG MCX Owners Manual: Handling & Safety Instructions, PDF p. 56 (3.8.5 Folding Stock Installation/Removal))" }, { "id": "function-check", "title": "Function check", "checks": [ "Verify the rifle is unloaded with no magazine inserted before each step.", "Cycle the action by hand and confirm the bolt locks and returns fully to battery.", "With the selector on safe, press the trigger. The hammer must not fall.", "Move the selector to fire, cycle the action, and press the trigger. The hammer should fall.", "Hold the trigger back, cycle the action, and release slowly to feel the disconnector reset.", "Confirm the magazine seats and locks positively and any hold-open engages on an empty magazine.", "Confirm the gas regulator is on the correct setting for how you are shooting the rifle." ], "videos": [] } ], "troubleshooting": [], "sources": [ { "n": 1, "id": null, "title": "SIG Sauer MCX Operator’s Manual", "publisher": "SIG Sauer, Inc.", "reliability": "primary", "url": null, "accessed": null }, { "n": 2, "id": "fix-it-sticks-compiled-reference-lis-f5c37b", "title": "Torque Specs (Torque Specs by Brand — Sig Sauer MCX)", "publisher": "Fix It Sticks (compiled reference list)", "reliability": "tertiary", "url": "https://store.fixitsticks.com/pages/torque-specs", "accessed": "2026-09-27" }, { "n": 3, "id": "sig-sauer-inc-b7b33f", "title": "SIG MCX Owners Manual: Handling & Safety Instructions", "publisher": "SIG SAUER, Inc.", "reliability": "primary", "url": "https://www.sigsauer.com/media/sigsauer/resources/MCX.pdf", "accessed": "2026-09-27" }, { "n": 4, "id": "sig-sauer-inc-7a56b7", "title": "SIG MCX VIRTUS Operator's Manual: Handling & Safety Instructions (2402117-01 REV 00)", "publisher": "SIG SAUER, Inc.", "reliability": "primary", "url": "https://www.sigsauer.com/pub/media/sigsauer/resources/OPERATORS-MANUAL-SIGMCX-VIRTUS-ENGLISH-2402117-01-REV-00-LR.pdf", "accessed": "2026-09-27" }, { "n": 5, "id": "sig-sauer-inc-da0075", "title": "SIG MCX-SPEAR LT Operator's Manual: Handling & Safety Instructions (2402988-01 REV00)", "publisher": "SIG SAUER, Inc.", "reliability": "primary", "url": "https://www.sigsauer.com/media/sigsauer/resources/OPERATORS-MANUAL-MCX-SPEAR-LT-2402988-01-REV00-WEB-FILE.pdf", "accessed": "2026-09-27" }, { "n": 6, "id": "arisaka-defense-5b19ff", "title": "Arisaka Zero Retention Clamp — MCX Virtus (SIG Standard / SIG SD Suppressor / MI Standard / MI Suppressor handguards), dated 07/25/2023 (ArisakaZRC-Virtus-03)", "publisher": "Arisaka Defense", "reliability": "secondary", "url": "https://arisakadefense.com/content/ArisakaZRC-Virtus-03.pdf", "accessed": "2026-10-11" }, { "n": 7, "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" } ] }