TacFire KeyMod Picatinny Rail — 5" / 11-Slot, Black Anodized (Model MAR103 / UPC 811261026445)
Give your KeyMod handguard the flexibility to mount legacy Picatinny accessories with the TacFire KeyMod Picatinny Rail (MAR103). This compact, 5-inch rail section provides 11 Picatinny slots of secure, M1913-style mounting real estate in a lightweight, low-profile package — perfect for lights, lasers, backup sights, bipods, vertical grips, or any accessory that still rides on a Picatinny footprint. Built for modular rifle systems, the MAR103 turns KeyMod slots into a reliable, repeatable platform for the accessories you rely on.
Fast overview
Model: TacFire MAR103
UPC: 811261026445
Type: KeyMod to Picatinny rail section
Length: 5 inches
Slots: 11 Picatinny/Weaver-style slots
Finish: Black anodized (matte)
Use: Mount Picatinny accessories on KeyMod handguards
Why add this rail to your build?
Modern free-float handguards are often KeyMod or M-LOK only, but many proven accessories still use Picatinny interfaces. The TacFire 5" KeyMod Picatinny rail gives you the best of both worlds — the lightweight, modular KeyMod platform plus a rugged, repeatable Picatinny surface where you need it most. Use it to position a tactical light ahead of your grip, mount a laser for close work, add a short bipod, or set a backup iron sight — all with the stability and repeatability of a Picatinny rail.
Key features & benefits
Secure Picatinny mounting: 11 full-length Picatinny slots provide plenty of room for most small-to-medium accessories.
KeyMod interface: Attaches quickly and securely to KeyMod-pattern handguards without bulky clamps.
Lightweight aluminum construction: Precision machined from aircraft-grade aluminum for strength without excess weight.
Durable black anodized finish: Low-glare surface resists corrosion and wear in the field.
Low profile, tactical footprint: Adds function without significantly changing your handguard ergonomics or balance.
Straightforward installation: Typically installs with included KeyMod screws/nuts — no special tools required beyond an Allen wrench.
Repeatable fit: Tight tolerances minimize movement and eliminate wobble when properly installed.
Versatile placement: Ideal for spot placement where full continuous rails would be overkill.
Typical Applications
Mounting weapon lights or IR illuminators near the muzzle for close engagements.
Attaching laser aiming modules for quick target acquisition.
Adding a short bipod or hand stop for stability and control.
Mounting backup iron sights or small optics that require a Picatinny footprint.
Customizing competition or duty rifles with hybrid KeyMod + Picatinny layouts.
Compatibility & fitment notes
Designed specifically for KeyMod patterned handguards. Not compatible with M-LOK without an adapter.
Confirm your handguard’s KeyMod slots are free of debris and aligned before installation.
Works with most Picatinny/Weaver accessories that accept standard 1913 rail mounting.
If your handguard uses proprietary hardware or non-standard KeyMod spacing, verify fitment prior to purchase.
Installation (high-level)
Align the rail’s KeyMod tabs with the handguard’s KeyMod slot.
Slide forward so the rail seats in the KeyMod cutout’s toe.
Tighten the supplied screws/nuts using the included Allen wrench or a compatible driver until the rail is snug — avoid over-torquing.
Confirm there is no movement; re-check torque after initial use.
(If your kit did not include hardware, use KeyMod-specific mounting screws and captive nuts sized for your handguard.)
Care & maintenance
Wipe clean with a soft cloth after use; remove grit or carbon buildup from the mounting surfaces.
Inspect mounting screws periodically and re-torque to maintain a solid, wobble-free fit.
Anodized finish is durable but avoid harsh abrasives to preserve the matte surface.
Frequently Asked Questions (FAQ)
Q: Will this rail add a lot of weight to my handguard?
A: No — a 5" aluminum rail section is very lightweight and designed to add minimal mass while providing crucial mounting real estate.
Q: Can I install this on an M-LOK handguard?
A: Not directly. This part is KeyMod-specific. For M-LOK you’ll need a dedicated M-LOK to Picatinny adapter or a rail section designed for M-LOK.
Q: Are mounting screws included?
A: Most MAR103 kits include KeyMod fastening hardware; check your seller listing. If hardware isn’t included, use KeyMod-compatible screws and nuts sized for your handguard.
Q: Will it hold a heavy weapon light or bipod?
A: Yes for most compact lights and short bipods when properly installed and torque-checked. For heavier accessories or extreme use, consider mounting across multiple rail sections or using reinforced mounting solutions.
Technical specifications (at a glance)
Manufacturer: TacFire
Model: MAR103
UPC: 811261026445
Mount Type: KeyMod to Picatinny rail section
Length: 5.00 inches
Picatinny Slots: 11
Material: Aircraft-grade aluminum (precision machined)
Finish: Black anodized (matte)
Weight: Lightweight (typical for 5" aluminum section)
Included: Rail section and KeyMod mounting hardware (verify with seller)
SEO-Friendly Summary
The TacFire KeyMod Picatinny Rail (MAR103) is a compact 5" / 11-slot rail section that converts KeyMod slots into a secure Picatinny mounting surface. Precision machined from aluminum and finished in black anodized, the MAR103 is ideal for attaching lights, lasers, backup sights, and short bipods to KeyMod handguards — giving modular rifle builders reliable Picatinny functionality exactly where it’s needed. UPC: 811261026445.
Add targeted functionality to your KeyMod handguard without the bulk of a full rail — the TacFire 5" KeyMod Picatinny Rail (MAR103) delivers secure, repeatable mounting for mission-critical accessories.
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