Rs Reg Front-Biased Yugo Modular Lower Receiver - Precision Engineered

The RS Regulate Yugo Lower-Biased Modular Lower Receiver is the foundation of a rock-solid optic mounting system for Yugo and Serbian pattern AK rifles. If you've got a Zastava M21, PAP, NPAP, or OPAP and want to mount modern tactical optics with precision and confidence, this lower mount pairs with RS Regulate's modular upper mounts to bring AR-15-style optics onto your AK platform. Unlike traditional AK side-rail mounts that can be finicky, the RS AK-300 system is engineered to hold zero and let you dial in proper eye relief and head position—without modifying your rifle or interfering with its operation.

Built from 6061 T6 aluminum and finished in durable matte black hardcoat anodize, this lower receiver is lightweight but built to last. The titanium locking mechanism is low-profile and stays out of your way—it won't protrude from the mount or into your trigger guard. Installation hardware is included; all you need to add is the optic-specific upper mount that matches your particular optic (sold separately). The modular design means you can adjust both the vertical over-bore height and front-to-back position of your optic to dial in the perfect setup for your shooting style and rifle geometry.

This is the front-biased version, designed specifically for Yugo rifles with a front-biased lower rail. If your rifle has a full-length lower rail, you'll want the AK-307M instead. The RS Regulate system is purpose-built to work with your rifle as-is—no permanent modifications, no reliability compromises, just repeatable mounting that holds your optic exactly where you put it.

Key Features

• Modular mount system compatible with Zastava M21, PAP, NPAP, and OPAP Yugo rifles
• Precision adjustment for vertical height and front-to-back optic positioning
• 6061 T6 aluminum construction with matte black hardcoat anodized finish
• Low-profile titanium locking mechanism—won't interfere with charging handle or trigger guard
• Installation hardware included; requires matching optic-specific upper mount (sold separately)
• No permanent rifle modifications required

Specifications

Frequently Asked Questions

What rifles does the Yugo lower receiver fit?

This front-biased lower mount is designed for Yugo and Serbian pattern rifles including the Zastava M21, PAP, NPAP, and OPAP. It specifically fits rifles with a front-biased lower side rail. If your rifle has a full-length lower rail, the AK-307M is the correct choice.

Do I need an upper mount to use this lower receiver?

Yes. The RS Regulate AK-300 system is modular—the lower receiver attaches to your rifle's side rail, and you pair it with an optic-specific upper mount that matches your particular optic. The upper mount is sold separately.

Will this mount require me to modify my rifle?

No. The RS Regulate mounting system is designed to work with your rifle without any permanent modifications. It also won't interfere with the reliable operation of your rifle or block access to the charging handle and trigger guard.

What's included in the box?

The lower receiver comes with all necessary installation hardware. You'll need to purchase the matching optic-specific upper mount separately.