{ "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": "cz-457", "name": "CZ 457", "manufacturer": { "id": "cz", "name": "Česká zbrojovka (CZ)" }, "category": "rimfire-rifle", "action": "bolt-action", "calibers": [ ".22 Long Rifle", ".22 WMR", ".17 HMR" ], "alsoKnownAs": [ "CZ 457 Lux", "CZ 457 American", "CZ 455 (predecessor)" ], "coversAlso": [ "CZ 455 (similar interchangeable-barrel system)", "CZ 457 Varmint, American, Lux, and At-One variants" ], "page": "firearms/cz-457.html", "bundle": "api/v1/firearms/cz-457.json", "lastUpdated": "2026-10-29" }, "notices": [ "This work order is written for the CZ 457. It is reported to cover CZ 455 (similar interchangeable-barrel system); CZ 457 Varmint, American, Lux, and At-One variants — 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": "high", "verification": "manufacturer-manual-verified" }, "manufacturerDisassembly": { "status": "published", "limit": null, "statement": "CZ publishes bolt removal as the owner's strip and says not to go further: adjustment or repair goes to a competent gunsmith, and after heavy use CZ advises having a gunsmith clean the bolt.", "source": { "title": "CZ 457 Instruction Manual", "publisher": "Česká zbrojovka a.s. Uherský Brod", "reliability": "primary", "url": "https://czubstrapiwebsitestorage.blob.core.windows.net/strapi-global/assets/735342000443_CZ_457_05_2025_en_es_cs_de_fr_48cf870932.pdf", "page": "9", "pdfPage": 10, "pageUrl": "https://czubstrapiwebsitestorage.blob.core.windows.net/strapi-global/assets/735342000443_CZ_457_05_2025_en_es_cs_de_fr_48cf870932.pdf#page=10", "quote": "Do not strip your firearm any further. If you assume that your firearm requires adjustment or repair, entrust this work to a competent gunsmith in a specialized workshop!" } }, "recalls": [], "shopTier": { "tier": 1, "group": "rimfire-rifle", "rating": "Pew-Takedown editorial rating (1 easy – 3 hardest), not the manufacturer's", "reason": "Bolt-action: the barrelled action comes out of the stock on two screws, the bolt comes out on its catch, and the trigger mechanism is an adjustable unit that a shop removes whole rather than strips. The long list (96 rows, 109 pieces) covers many variant and stock parts; the only care points are the striker spring in the bolt and action-screw torque.", "confidence": "medium", "partCount": { "value": 96, "kind": "line-items", "covers": "Single CZ 457 list covering all 457 variants (rows marked * vary by model), incl. spare-parts assemblies; 96 rows", "basis": "manufacturer-parts-list", "source": { "title": "CZ 457 Instruction Manual", "publisher": "Česká zbrojovka a.s. Uherský Brod", "reliability": "primary", "url": "https://czubstrapiwebsitestorage.blob.core.windows.net/strapi-global/assets/735342000443_CZ_457_05_2025_en_es_cs_de_fr_48cf870932.pdf", "page": "12", "pdfPage": 13, "pageUrl": "https://czubstrapiwebsitestorage.blob.core.windows.net/strapi-global/assets/735342000443_CZ_457_05_2025_en_es_cs_de_fr_48cf870932.pdf#page=13", "quote": "L Cheekpiece" } }, "painPoints": [ { "issue": "CZ says not to strip the rifle past bolt removal and to hand the bolt to a gunsmith for cleaning; the trigger mechanism is adjustable and should be left as a unit.", "during": "both", "source": { "title": "CZ 457 Instruction Manual", "publisher": "Česká zbrojovka a.s. Uherský Brod", "reliability": "primary", "url": "https://czubstrapiwebsitestorage.blob.core.windows.net/strapi-global/assets/735342000443_CZ_457_05_2025_en_es_cs_de_fr_48cf870932.pdf", "page": null, "pdfPage": null, "pageUrl": null, "quote": "Do not strip your firearm any further. If you assume that your firearm requires adjustment or repair, entrust this work to a competent gunsmith in a specialized workshop!" } }, { "issue": "Stock screws must go back to a set torque.", "during": "reassembly", "source": { "title": "CZ 457 Instruction Manual", "publisher": "Česká zbrojovka a.s. Uherský Brod", "reliability": "primary", "url": "https://czubstrapiwebsitestorage.blob.core.windows.net/strapi-global/assets/735342000443_CZ_457_05_2025_en_es_cs_de_fr_48cf870932.pdf", "page": null, "pdfPage": null, "pageUrl": null, "quote": "Check tightening of the stock fixing screws (pos. 73 and 74) and tighten them as necessary with the torque of 3.5 Nm." } } ], "minutes": { "strip": 25, "rebuild": 35, "basis": "estimated", "note": "Action out of the stock on two screws, bolt stripped (striker, extractors), trigger unit off as a whole, sights; rebuild mostly the bolt and action-screw torque.", "source": null }, "stripScope": [ { "assembly": "Stock", "removes": [ "stock fixing screws (pos. 73, 74)", "barrelled action out of the stock" ] }, { "assembly": "Action", "removes": [ "bolt (bolt catch)", "trigger mechanism as a unit", "magazine catch", "sights / scope base" ] }, { "assembly": "Bolt", "removes": [ "cocking piece and striker with spring", "extractors" ] } ], "hardware": { "pins": 8, "springs": 10, "detents": 2, "basis": "counted from the manufacturer's parts list (one per key number unless a quantity is given)" }, "specialTools": [ { "tool": "Torque driver (3.5 Nm)", "usedFor": "Stock fixing screws" }, { "tool": "Sight pusher", "usedFor": "Dovetail sights, if fitted" } ], "fitOnRebuild": [ { "check": "Stock screw torque 3.5 Nm", "why": "Inconsistent action-screw torque shifts zero.", "source": { "title": "CZ 457 Instruction Manual", "publisher": "Česká zbrojovka a.s. Uherský Brod", "reliability": "primary", "url": "https://czubstrapiwebsitestorage.blob.core.windows.net/strapi-global/assets/735342000443_CZ_457_05_2025_en_es_cs_de_fr_48cf870932.pdf", "page": null, "pdfPage": null, "pageUrl": null, "quote": "tighten them as necessary with the torque of 3.5 Nm." } }, { "check": "Trigger pull and travel check", "why": "The trigger is adjustable; confirm it is unchanged after the unit comes off.", "source": null }, { "check": "Re-zero", "why": "Sights or scope base removed.", "source": null } ], "assessed": "2026-10-29" }, "videos": [ { "title": "How to Change the Stock on a CZ 457", "url": "https://www.youtube.com/watch?v=5S0M1MEWNYI", "platform": "youtube", "embedUrl": null, "shows": [ "adjustment", "field-strip" ], "appliesTo": "CZ 457", "published": "2026-09-15", "note": null, "channel": { "id": "UCbdPQRXAzqkD0VFwEwmsgqQ", "name": "CZ Firearms", "url": "https://www.youtube.com/@CZ_Firearms", "owner": "Česká zbrojovka a.s. (Czech Republic)" }, "accessed": "2026-10-15" }, { "title": "How to Change the Barrel and Caliber on a CZ 457", "url": "https://www.youtube.com/watch?v=mnSKzzLABuU", "platform": "youtube", "embedUrl": null, "shows": [ "adjustment", "detail-strip", "detail-reassembly" ], "appliesTo": "CZ 457", "published": "2026-09-15", "note": null, "channel": { "id": "UCbdPQRXAzqkD0VFwEwmsgqQ", "name": "CZ Firearms", "url": "https://www.youtube.com/@CZ_Firearms", "owner": "Česká zbrojovka a.s. (Czech Republic)" }, "accessed": "2026-10-15" }, { "title": "How to Adjust the Trigger on a CZ 457", "url": "https://www.youtube.com/watch?v=TayJ6quo2U0", "platform": "youtube", "embedUrl": null, "shows": [ "adjustment" ], "appliesTo": "CZ 457", "published": "2026-09-15", "note": null, "channel": { "id": "UCbdPQRXAzqkD0VFwEwmsgqQ", "name": "CZ Firearms", "url": "https://www.youtube.com/@CZ_Firearms", "owner": "Česká zbrojovka a.s. (Czech Republic)" }, "accessed": "2026-10-15" }, { "title": "How to Disassemble the CZ 457 Magazine", "url": "https://www.youtube.com/watch?v=nOVwABWuPa8", "platform": "youtube", "embedUrl": null, "shows": [ "detail-strip", "maintenance" ], "appliesTo": "CZ 457 magazine", "published": "2026-09-15", "note": null, "channel": { "id": "UCbdPQRXAzqkD0VFwEwmsgqQ", "name": "CZ Firearms", "url": "https://www.youtube.com/@CZ_Firearms", "owner": "Česká zbrojovka a.s. (Czech Republic)" }, "accessed": "2026-10-15" } ], "configurations": [], "tools": [ { "name": "Bore guide", "required": true, "usedFor": "Cleaning from the breech without damaging the throat or the crown.", "substitute": "There is no good substitute. A rod run into an unguided chamber scrapes the throat." }, { "name": "Hex key or screwdriver matching the action screws", "required": false, "usedFor": "Removing the barrelled action from the stock. Not needed for routine cleaning." }, { "name": "Torque wrench", "required": false, "usedFor": "Reinstalling action screws to a consistent value, which is an accuracy variable on every bolt rifle." } ], "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 safety in the on position." }, { "n": 3, "instruction": "Lift the bolt handle and draw the bolt fully rearward, extracting and ejecting any chambered round." }, { "n": 4, "instruction": "Remove the detachable magazine.", "partsFreed": [ "Magazine contents" ] }, { "n": 5, "instruction": "Inspect the chamber and magazine well with a light and 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": [ { "title": "How to Change the Stock on a CZ 457", "url": "https://www.youtube.com/watch?v=5S0M1MEWNYI", "platform": "youtube", "embedUrl": null, "shows": [ "adjustment", "field-strip" ], "appliesTo": "CZ 457", "published": "2026-09-15", "note": null, "channel": { "id": "UCbdPQRXAzqkD0VFwEwmsgqQ", "name": "CZ Firearms", "url": "https://www.youtube.com/@CZ_Firearms", "owner": "Česká zbrojovka a.s. (Czech Republic)" }, "accessed": "2026-10-15" }, { "title": "How to Change the Barrel and Caliber on a CZ 457", "url": "https://www.youtube.com/watch?v=mnSKzzLABuU", "platform": "youtube", "embedUrl": null, "shows": [ "adjustment", "detail-strip", "detail-reassembly" ], "appliesTo": "CZ 457", "published": "2026-09-15", "note": null, "channel": { "id": "UCbdPQRXAzqkD0VFwEwmsgqQ", "name": "CZ Firearms", "url": "https://www.youtube.com/@CZ_Firearms", "owner": "Česká zbrojovka a.s. (Czech Republic)" }, "accessed": "2026-10-15" }, { "title": "How to Disassemble the CZ 457 Magazine", "url": "https://www.youtube.com/watch?v=nOVwABWuPa8", "platform": "youtube", "embedUrl": null, "shows": [ "detail-strip", "maintenance" ], "appliesTo": "CZ 457 magazine", "published": "2026-09-15", "note": null, "channel": { "id": "UCbdPQRXAzqkD0VFwEwmsgqQ", "name": "CZ Firearms", "url": "https://www.youtube.com/@CZ_Firearms", "owner": "Česká zbrojovka a.s. (Czech Republic)" }, "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 remove the magazine." }, { "n": 2, "instruction": "Shift the safety to its Off position. The bolt will not come out with the safety engaged.", "warning": "The safety is off from here on. Muzzle discipline matters more than ever." }, { "n": 3, "instruction": "Open the bolt, depress the bolt catch, and pull the bolt out of the rifle.", "partsFreed": [ "Bolt" ] }, { "n": 4, "instruction": "Clean the bore from the breech using a bore guide, and clean the bolt face, lugs, and chamber." }, { "n": 6, "instruction": "While the rifle is apart, check that the two stock fixing screws are tight; the manual specifies 3.5 Nm.", "tip": "Torque, not feel. Over-tightening a rimfire action into its stock will shift point of impact." } ] }, { "procedure": "stock-removal", "title": "Remove the Barrelled Action from the Stock", "level": "detail-strip", "configuration": false, "steps": [ { "n": 1, "instruction": "Verify the rifle is unloaded and remove the bolt and magazine." }, { "n": 2, "instruction": "Remove the action screws from the bottom of the stock, noting which screw came from which hole.", "tip": "They are often different lengths.", "partsFreed": [ "Action screws", "Floorplate or magazine assembly" ] }, { "n": 3, "instruction": "Lift the barrelled action out of the stock.", "partsFreed": [ "Stock" ] } ] } ] }, { "id": "refinish", "title": "Refinish", "components": [ { "name": "Bolt", "procedure": "field-strip", "level": "field-strip", "step": 3 }, { "name": "Action screws", "procedure": "stock-removal", "level": "detail-strip", "step": 2 }, { "name": "Floorplate or magazine assembly", "procedure": "stock-removal", "level": "detail-strip", "step": 2 }, { "name": "Stock", "procedure": "stock-removal", "level": "detail-strip", "step": 3 } ], "manufacturerPartsList": { "parts": 96, "scope": "Single CZ 457 list (English section) covering all 457 variants; rows marked * vary by model or are absent in some. Includes the \"Spare parts assemblies\" sub-list (M, H1, H2, V, Z, S, L). ES/CS/DE/FR copies omitted." }, "partsDiagrams": [], "materials": [ { "component": "Stock", "material": "walnut", "finish": "varnished", "appliesTo": "CZ 457 American", "note": null, "source": { "title": "CZ 457 American", "publisher": "CZ-USA", "reliability": "primary", "url": "https://cz-usa.com/product/cz-457-american/", "page": null, "pdfPage": null, "pageUrl": null, "quote": "The varnished American-style stock is made from high quality walnut, with checkering on the grip that incorporates a fleur-de-lis motif." } } ], "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": "How to Change the Barrel and Caliber on a CZ 457", "url": "https://www.youtube.com/watch?v=mnSKzzLABuU", "platform": "youtube", "embedUrl": null, "shows": [ "adjustment", "detail-strip", "detail-reassembly" ], "appliesTo": "CZ 457", "published": "2026-09-15", "note": null, "channel": { "id": "UCbdPQRXAzqkD0VFwEwmsgqQ", "name": "CZ Firearms", "url": "https://www.youtube.com/@CZ_Firearms", "owner": "Česká zbrojovka a.s. (Czech Republic)" }, "accessed": "2026-10-15" } ], "procedures": [ { "procedure": "stock-removal", "title": "Remove the Barrelled Action from the Stock", "configuration": false, "steps": [ { "n": 4, "instruction": "To reinstall, seat the action in the stock, start both screws by hand, then tighten the front screw first and the rear second to a consistent torque.", "warning": "Inconsistent action screw torque is one of the most common causes of a rifle that will not hold zero. Consult your stock maker’s specification rather than guessing." } ], "instruction": null }, { "procedure": "reassembly", "title": "Reassembly", "configuration": false, "steps": [ { "n": 1, "instruction": "Confirm the bolt is correctly assembled and the bolt head is properly oriented." }, { "n": 2, "instruction": "Align the bolt with the receiver raceway and slide it forward into the action." }, { "n": 3, "instruction": "Close the bolt handle and cycle the bolt several times to confirm smooth travel and correct cocking." }, { "n": 4, "instruction": "Confirm the bolt release retains the bolt when the action is opened fully." }, { "n": 5, "instruction": "Perform the function check." } ], "instruction": null } ] }, { "id": "torque", "title": "Torque", "coverage": "sourced", "manufacturer": [ { "fastener": "Stock fixing screws (key nos. 73 and 74)", "appliesTo": null, "qualifier": "exact", "value": 3.5, "valueMax": null, "unit": "N-m", "converted": { "value": { "N-m": 3.5, "in-lb": 31, "ft-lb": 2.6 }, "valueMax": null }, "sequence": null, "threadlocker": null, "source": { "title": "CZ 457 Instruction Manual", "publisher": "Česká zbrojovka a.s. Uherský Brod", "reliability": "primary", "url": "https://czubstrapiwebsitestorage.blob.core.windows.net/strapi-global/assets/735342000443_CZ_457_05_2025_en_es_cs_de_fr_48cf870932.pdf", "page": "9", "pdfPage": 10, "pageUrl": "https://czubstrapiwebsitestorage.blob.core.windows.net/strapi-global/assets/735342000443_CZ_457_05_2025_en_es_cs_de_fr_48cf870932.pdf#page=10", "quote": "Check tightening of the stock fixing screws (pos. 73 and 74) and tighten them as necessary with the torque of 3.5 Nm." } } ], "reported": [ { "fastener": "Action screws (both)", "appliesTo": "CZ 457 in a KRG Bravo Chassis (Gen 2)", "qualifier": "exact", "value": 45, "valueMax": null, "unit": "in-lb", "converted": { "value": { "N-m": 5.1, "in-lb": 45, "ft-lb": 3.7 }, "valueMax": null }, "sequence": null, "threadlocker": null, "source": { "title": "KRG Bravo Chassis (Gen 2) Installation Instructions (INST-BRV)", "publisher": "Kinetic Research Group (KRG)", "reliability": "secondary", "url": "https://kineticresearchgroup.com/download/79805/", "page": "PDF p. 2", "pdfPage": 2, "pageUrl": "https://kineticresearchgroup.com/download/79805/#page=2", "quote": "***for CZ-457 ONLY apply 45 in-lbs of torque to each action screw." } }, { "fastener": "Action screws (front and rear)", "appliesTo": "CZ 457 in an MDT Oryx chassis", "qualifier": "range", "value": 15, "valueMax": 45, "unit": "in-lb", "converted": { "value": { "N-m": 1.7, "in-lb": 15, "ft-lb": 1.2 }, "valueMax": { "N-m": 5.1, "in-lb": 45, "ft-lb": 3.7 } }, "sequence": "Push the action rearward against the recoil lug and torque the front action screw first, then the rear (manual p. 1: 'first torquing the front then the rear action screw').", "threadlocker": null, "source": { "title": "MDT Oryx Chassis System — User Manual (13694, Version 07.14.26), attached to MDT help-centre article 'ORYX Chassis Installation Guides'", "publisher": "MDT Sporting Goods Ltd. (Modular Driven Technologies, MDT)", "reliability": "secondary", "url": "https://support.mdttac.com/hc/article_attachments/51468856863892", "page": "PDF p. 2 (inlet-specific torque table)", "pdfPage": 2, "pageUrl": "https://support.mdttac.com/hc/article_attachments/51468856863892#page=2", "quote": "CZ457 — 5mm Hex Wrench — 15-45 inch-pounds" } }, { "fastener": "Action screws (front and rear)", "appliesTo": "CZ 457 in an MDT Field Stock (same row in the MDT XRS chassis manual)", "qualifier": "range", "value": 20, "valueMax": 45, "unit": "in-lb", "converted": { "value": { "N-m": 2.3, "in-lb": 20, "ft-lb": 1.7 }, "valueMax": { "N-m": 5.1, "in-lb": 45, "ft-lb": 3.7 } }, "sequence": "Front then rear.", "threadlocker": null, "source": { "title": "MDT Field Stock — User Manual (13739, Version 03.3.26), attached to MDT help-centre article 'Field Stock Installation' (image-only PDF; read from the rendered page)", "publisher": "MDT Sporting Goods Ltd. (Modular Driven Technologies, MDT)", "reliability": "secondary", "url": "https://support.mdttac.com/hc/article_attachments/51745558131092", "page": "PDF p. 2 (inlet-specific torque table)", "pdfPage": 2, "pageUrl": "https://support.mdttac.com/hc/article_attachments/51745558131092#page=2", "quote": "CZ457 — 4mm Hex Wrench — 20-45 inch-pounds" } }, { "fastener": "Action screws (front and rear)", "appliesTo": "CZ 457 in an MDT LSS Gen3 chassis (same row in the MDT ACC Premier Gen2 manual)", "qualifier": "exact", "value": 45, "valueMax": null, "unit": "in-lb", "converted": { "value": { "N-m": 5.1, "in-lb": 45, "ft-lb": 3.7 }, "valueMax": null }, "sequence": "Front then rear.", "threadlocker": null, "source": { "title": "MDT LSS Gen3 Chassis — User Manual (13735, Version 07.07.26 / table page 06.04.26), attached to MDT help-centre article 'LSS GEN3 Chassis Installation'", "publisher": "MDT Sporting Goods Ltd. (Modular Driven Technologies, MDT)", "reliability": "secondary", "url": "https://support.mdttac.com/hc/article_attachments/51874557357204", "page": "PDF p. 2 (inlet-specific torque table)", "pdfPage": 2, "pageUrl": "https://support.mdttac.com/hc/article_attachments/51874557357204#page=2", "quote": "CZ457 — 4mm Hex Wrench — 45 inch-pounds" } }, { "fastener": "Action screws (front then back)", "appliesTo": "CZ 457 in an MDT ACC Elite chassis", "qualifier": "maximum", "value": 45, "valueMax": null, "unit": "in-lb", "converted": { "value": { "N-m": 5.1, "in-lb": 45, "ft-lb": 3.7 }, "valueMax": null }, "sequence": "Push the action back towards the buttstock; tighten front then back. 'Torque to preference while tuning, ensuring the final torque does not exceed 45 in-lbs.'", "threadlocker": null, "source": { "title": "MDT ACC Elite Chassis System — User Manual (13733, Version 01.20.2026), attached to MDT help-centre article 'ACC Elite Chassis System Installation Guides/Manual' (image-only PDF; read from the rendered page)", "publisher": "MDT Sporting Goods Ltd. (Modular Driven Technologies, MDT)", "reliability": "secondary", "url": "https://support.mdttac.com/hc/article_attachments/50441627587092", "page": "PDF p. 3 ('CZ457 Installation', step 3)", "pdfPage": 3, "pageUrl": "https://support.mdttac.com/hc/article_attachments/50441627587092#page=3", "quote": "3. While pushing the action back towards the buttstock, insert the supplied action screws, using a 4MM Hex Drive, torque up to 45 inch-pounds, first tightening the front then back action screw." } }, { "fastener": "Scope base clamp screws (4)", "appliesTo": "CZ 452 / CZ 455 / CZ 457 with the MDT CZ Rimfire Scope Base", "qualifier": "range", "value": 15, "valueMax": 20, "unit": "in-lb", "converted": { "value": { "N-m": 1.7, "in-lb": 15, "ft-lb": 1.2 }, "valueMax": { "N-m": 2.3, "in-lb": 20, "ft-lb": 1.7 } }, "sequence": "Slide the rail forward until its recoil lug bears on the front of the ejection port, then torque; re-check after 100-150 rounds.", "threadlocker": null, "source": { "title": "MDT CZ Rimfire Scope Base (CZ 452, CZ 455, CZ 457) — Instructions V2.0 April 2022, attached to MDT help-centre article 'CZ 452/455/457 scope base installation'", "publisher": "MDT Sporting Goods Ltd. (Modular Driven Technologies, MDT)", "reliability": "secondary", "url": "https://support.mdttac.com/hc/article_attachments/30236314345748", "page": "PDF p. 3, step 4", "pdfPage": 3, "pageUrl": "https://support.mdttac.com/hc/article_attachments/30236314345748#page=3", "quote": "4. Torque all screws to 15-20 in-lb. After taking out your CZ for some fun (100-150 rounds), check all four screws and re-torque if necessary." } }, { "fastener": "Action screws (front then back)", "appliesTo": "CZ 457 in an XLR chassis (supplied recoil lug placed in the lug pocket)", "qualifier": "exact", "value": 35, "valueMax": null, "unit": "in-lb", "converted": { "value": { "N-m": 4, "in-lb": 35, "ft-lb": 2.9 }, "valueMax": null }, "sequence": "Stand the rifle on the recoil pad to seat the lug, hand-tighten front then back, then torque front then back.", "threadlocker": null, "source": { "title": "XLR Industries — Chassis & Buttstock Instructions (2022), linked from xlrindustries.com 'XLR Chassis System Instructions' (image-only PDF; read from the rendered page)", "publisher": "XLR Industries", "reliability": "secondary", "url": "https://cdn.shopify.com/s/files/1/0995/2330/files/ChassisButtstock-Instructions-2022.pdf?v=1657120420", "page": "PDF p. 3, step 8", "pdfPage": 3, "pageUrl": "https://cdn.shopify.com/s/files/1/0995/2330/files/ChassisButtstock-Instructions-2022.pdf?v=1657120420#page=3", "quote": "• For CZ-457 and Anschutz torque to 35 INCH-pounds." } } ], "notes": null }, { "id": "function-check", "title": "Function check", "checks": [ "Verify the rifle is unloaded and the magazine is empty before each check.", "Cycle the bolt and confirm it cocks and closes fully into battery.", "With the action cocked, engage the safety and press the trigger. The firing pin must not release.", "Disengage the safety without touching the trigger. The firing pin must not release.", "Press the trigger and confirm the firing pin releases cleanly.", "Confirm the bolt release retains the bolt.", "Load dummy rounds and confirm they feed from the magazine and eject cleanly." ], "videos": [] } ], "troubleshooting": [], "sources": [ { "n": 1, "id": "cz-457-manual", "title": "CZ 457 Instruction Manual", "publisher": "Česká zbrojovka a.s. Uherský Brod", "reliability": "primary", "url": "https://czubstrapiwebsitestorage.blob.core.windows.net/strapi-global/assets/735342000443_CZ_457_05_2025_en_es_cs_de_fr_48cf870932.pdf", "accessed": "2026-09-14" }, { "n": 2, "id": "kinetic-research-group-krg-7bcb41", "title": "KRG Bravo Chassis (Gen 2) Installation Instructions (INST-BRV)", "publisher": "Kinetic Research Group (KRG)", "reliability": "secondary", "url": "https://kineticresearchgroup.com/download/79805/", "accessed": "2026-09-27" }, { "n": 3, "id": "cz-usa-specs-32c54d", "title": "CZ 457 American", "publisher": "CZ-USA", "reliability": "primary", "url": "https://cz-usa.com/product/cz-457-american/", "accessed": "2026-10-03" }, { "n": 4, "id": "mdt-sporting-goods-ltd-modular-drive-9d8d3c", "title": "MDT Oryx Chassis System — User Manual (13694, Version 07.14.26), attached to MDT help-centre article 'ORYX Chassis Installation Guides'", "publisher": "MDT Sporting Goods Ltd. (Modular Driven Technologies, MDT)", "reliability": "secondary", "url": "https://support.mdttac.com/hc/article_attachments/51468856863892", "accessed": "2026-10-11" }, { "n": 5, "id": "mdt-sporting-goods-ltd-modular-drive-5108b3", "title": "MDT Field Stock — User Manual (13739, Version 03.3.26), attached to MDT help-centre article 'Field Stock Installation' (image-only PDF; read from the rendered page)", "publisher": "MDT Sporting Goods Ltd. (Modular Driven Technologies, MDT)", "reliability": "secondary", "url": "https://support.mdttac.com/hc/article_attachments/51745558131092", "accessed": "2026-10-11" }, { "n": 6, "id": "mdt-sporting-goods-ltd-modular-drive-2e5c91", "title": "MDT LSS Gen3 Chassis — User Manual (13735, Version 07.07.26 / table page 06.04.26), attached to MDT help-centre article 'LSS GEN3 Chassis Installation'", "publisher": "MDT Sporting Goods Ltd. (Modular Driven Technologies, MDT)", "reliability": "secondary", "url": "https://support.mdttac.com/hc/article_attachments/51874557357204", "accessed": "2026-10-11" }, { "n": 7, "id": "mdt-sporting-goods-ltd-modular-drive-0f66dd", "title": "MDT ACC Elite Chassis System — User Manual (13733, Version 01.20.2026), attached to MDT help-centre article 'ACC Elite Chassis System Installation Guides/Manual' (image-only PDF; read from the rendered page)", "publisher": "MDT Sporting Goods Ltd. (Modular Driven Technologies, MDT)", "reliability": "secondary", "url": "https://support.mdttac.com/hc/article_attachments/50441627587092", "accessed": "2026-10-11" }, { "n": 8, "id": "mdt-sporting-goods-ltd-modular-drive-7e62d6", "title": "MDT CZ Rimfire Scope Base (CZ 452, CZ 455, CZ 457) — Instructions V2.0 April 2022, attached to MDT help-centre article 'CZ 452/455/457 scope base installation'", "publisher": "MDT Sporting Goods Ltd. (Modular Driven Technologies, MDT)", "reliability": "secondary", "url": "https://support.mdttac.com/hc/article_attachments/30236314345748", "accessed": "2026-10-11" }, { "n": 9, "id": "xlr-industries-cd365d", "title": "XLR Industries — Chassis & Buttstock Instructions (2022), linked from xlrindustries.com 'XLR Chassis System Instructions' (image-only PDF; read from the rendered page)", "publisher": "XLR Industries", "reliability": "secondary", "url": "https://cdn.shopify.com/s/files/1/0995/2330/files/ChassisButtstock-Instructions-2022.pdf?v=1657120420", "accessed": "2026-10-11" } ] }