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Zaffiri Precision Premium Upper Parts Kit (UPK) - Fits Glock 19 Gen 4 Slide Assemblies - Stainless Steel & Hardened Polymer Internal Components - UPK-G19G4
Product Description
When assembling a custom compact slide or giving your trusted everyday carry weapon a complete internal overhaul, tracking down separate small pins and springs is a hassle. Mixing and matching components from mystery brands often leads to stacked tolerance issues on your bench, leaving you with annoying light primer strikes, gritty firing pin drag, or an extractor that hangs up on chambered casings. The **Zaffiri Precision Premium Upper Parts Kit (UPK-G19G4)** solves this issue cleanly. It bundles every necessary small internal spring, plunger, rod, and liner into a single, high-quality package to guarantee your compact slide builds out completely level and runs flawlessly.
Every internal part in this kit is manufactured to meet or exceed original factory spec dimensions, using high-strength stainless steel and hardened polymers for critical wear items. The kit features a premium stainless steel firing pin assembly and heavy-duty striker spring engineered to deliver crisp, authoritative primer ignition across all ammunition types. It comes fully packaged with a precision safety plunger, an extractor depressor rod assembly, a standard-weight captured dual-spring recoil guide rod, and a durable polymer channel liner to protect the internal slide walls from spring scraping.
Instead of hoping separate loose parts work together smoothly, this kit gives you a calibrated, drop-in internal completion system. It is the ideal solution for populating a bare Zaffiri compact slide build, updating a high-mileage factory slide, or completing a custom Gen 4 multi-fit framework project.
*Armorer Bench Notes & Real-World Installation Guidance: This Zaffiri Precision Upper Parts Kit arrives organized with all internal small parts securely packaged within its factory container. CRITICAL GENERATION-SPECIFIC COMPATIBILITY DIRECTIVE: This component selection is engineered natively to fit Glock 19 Gen 4 slide architectures only. Because Generation 4 slides utilize a wider front nose ring shoulder to seat the larger dual-recoil spring assembly—yet still retain the cylindrical safety plunger style and specific firing pin safety spacing shapes of older generations—these parts will not interchange with Gen 3 or Gen 5 slides. Armorer Workbench Assembly Sequence: 1. Always use a dedicated channel liner tool to tap the polymer channel sleeve straight into the slide pocket—forcing it in crooked can warp the liner and cause a sluggish firing pin. 2. When locking the firing pin spring cups together over the striker spring tail, ensure they are seated completely flush before releasing tension. 3. Ensure the small plastic spring bearing at the base of the extractor rod faces outward to correctly support your slide backplate. Lubrication Parameter: Keep the inside of the striker channel liner completely dry. Spraying oils, liquid lubes, or grease inside the firing pin track collects loose powder soot and gun dust, creating a sticky paste that slows down the striker and triggers light primer strikes downrange.*
Key Features
- Complete Gen 4 Compact Array: Provides every single necessary small part, spring, plunger, and backplate required to fully populate a bare Gen 4 compact slide without missing components.
- Heavy-Duty Striker Core: Outfitted with a premium stainless steel firing pin assembly engineered to deliver clean vertical strikes and positive primer ignition.
- Turnkey Captured Guide Rod: Includes a standard-weight stainless steel guide rod with a pre-captured Gen 4 dual-recoil spring assembly, saving you assembly steps on the bench.
- High-Tensile Springs Pack: Features factory-calibrated spring rates across the striker, safety plunger, and extractor assemblies to maintain crisp timing.
- Self-Lubricating Channel Liner: Outfitted with a slick polymer sleeve designed to line the inner slide walls, preventing spring scraping and internal wear.
- Perfect Match-Grade Fit: Engineered to match original factory spec clearances precisely, completely eliminating stacked tolerance jams and slide binding.
Product Specifications
- Brand: Zaffiri Precision (Largo, Florida)
- Model Line: Factory Premium Slide Internal Component Overhaul Series
- MPN/SKU: UPK-G19G4 (Also cataloged as ZAF-UPK-G19G4-GEN4)
- UPC Code Profile: 810220065167
- Firearm Model Fitment: Glock® 19 Gen 4 Slides Only
- Striker Pin Base Material: Premium Ground Stainless Steel Core Billet
- Spring Composition Standard: High-Tensile Tempered Spring Steel Wire
- Recoil Guide Rod Style: Gen 4 Dual-Spring Captured Rod with Standard Factory Weight
- Channel Liner Profile: Injection-Molded Low-Friction Polymer Cylinder Sleeve
- Compatible Cartridge Caliber: 9x19mm Parabellum (9mm Luger / 9mm NATO)
- Full Kit Component Checklist: Firing Pin, Striker Spring, Spacer Sleeves, Spring Cups, Safety Plunger, Plunger Spring, Extractor Depressor Rod, Spring Bearing, Extractor Spring, Slide Cover Plate, Channel Liner, Captured Dual-Recoil Compact Guide Rod Assembly
- Packaging Format Class: Zaffiri Precision Multi-Compartment Factory Packaging
- Product Type Category: Handgun Small Parts / Slide Internal Assembly Kits
- Overall Fitment Class: Compact Gen 4 Slide Internals
- Net Kit Assembly Weight: ~2.50 Ounces (Total combined small parts mass)
- Country of Manufacture: Proudly Made in the United States of America
- Warranty Tracking Protection: Fully Backed by Zaffiri Precision Materials Guarantee
