Sport-4S Kit by Zenitco: Complete Overview and Installation Guide

Overview of the “Sport-4S” Kit by Zenitco

The “Sport-4S” kit is a modern upgrade solution designed for AK-platform rifles and carbines. It provides an extended, ergonomic grip and allows for the installation of additional accessories.

In this overview, weÂ’ll cover:

• key features
• differences from other models
• specifications
• installation process

Purpose and Compatibility

The “Sport-4S” is designed for firearms with a 415 mm barrel length, such as:

• AK-74M
• Saiga (configuration 30)

Not compatible with shorter models:

• AK-104
• AK-105
• Saiga configuration 33

For compact rifles, shorter kits like “Sport-1” are more suitable.
If you need a longer setup extending toward the front sight base, consider the “Leader” series.

Design and Materials

The kit is made from aircraft-grade reinforced aluminum and features a precision-machined construction.

Key elements:

• top low-profile Picatinny rail
• side “Basis” mounting interfaces
• reinforced lower interface
• integrated front mini Picatinny rail

This allows users to mount:

• flashlights
• laser aiming devices
• foregrips and other accessories

Difference from “Sport-4”

The main difference lies in the lower interface:

• Sport-4 - lightweight version
• Sport-4S -reinforced version

Mounting differences:

• lightweight ? cam-lock attachment
• reinforced ? screw-based mounting with steel inserts

Weight:

• Sport-4: ~313 g
• Sport-4S: ~350 g

The reinforcement adds only 37 g, while significantly improving durability.

When Reinforcement Matters

The reinforced version is recommended when:

• using long foregrips (creating leverage)
• applying higher mechanical stress
• operating in demanding conditions

For standard use, the lightweight version is often sufficient.

Kit Components

• B-10LS lower handguard rail – 1 pc
• B-31LV upper handguard rail – 1 pc
• DL-2S additional attachment rail – 1 pc
• Mounting plate (Sport-4S side bar) – 1 pc
• Cam clamp – 1 pc
• Leader hand stopper – 1 pc
• Picatinny fork – 1 pc
• Screws: M5x7 – 11 pcs, M5x9 – 1 pc
• User manuals – 4 pcs

The handguard can also be used independently.

Installation Process

1. Preparation

• ensure the firearm is unloaded
• remove the magazine
• perform basic disassembly

2. Removing Factory Parts

• receiver cover
• recoil spring assembly
• bolt carrier group
• gas tube
• factory handguard

3. Installing the Handguard

The handguard is installed using a tight-fit method:

• inserted into the receiver
• gently seated using a spacer and hammer

Important:
Aluminum slightly conforms to the receiver, ensuring a tight fit and consistent zero retention.

4. Assembly

• gas tube
• top mount
• front extension
• side clamp
• lower support
• front locking piece

All screws should be loosely fitted first, then fully tightened.

5. Final Setup

• check overall rigidity
• install additional accessories as needed

Final Thoughts

The “Sport-4S” offers:

• strong and reliable construction
• extended ergonomic grip
• versatile mounting platform

It occupies a middle ground between compact and extended solutions in the product lineup.

Conclusion

If you are looking for:

• a balance between length and handling
• enhanced structural rigidity
• maximum accessory compatibility

the “Sport-4S” is one of the most versatile options available.