Cross Machine Tool

Cross Machine Tool Upur-3A Billet AR-15 Side Charging Upper Receiver - Slick Side - .458 Socom Compatible

Cross Machine Tool Upur-3a Billet Ar-15 Side Charging Upper Receiver - Slick Side - .458 Socom Compatible - Upper Receiver for AR-15 - view 1
Cross Machine Tool Upur-3a Billet Ar-15 Side Charging Upper Receiver - Slick Side - .458 Socom Compatible - Upper Receiver for AR-15 - view 2
Cross Machine Tool Upur-3a Billet Ar-15 Side Charging Upper Receiver - Slick Side - .458 Socom Compatible - Upper Receiver for AR-15 - view 3
Cross Machine Tool Upur-3a Billet Ar-15 Side Charging Upper Receiver - Slick Side - .458 Socom Compatible - Upper Receiver for AR-15 - view 4

Cross Machine Tool

Overview

The Cross Machine Tool Upur-3a Billet AR-15 Side Charging Upper Receiver is a complete assembly designed for the .458 SOCOM caliber, featuring a slick side profile that enhances aesthetics and reduces weight. This upper receiver is compatible with AR-15 platforms and allows for a unique side charging operation, which can improve accessibility and maneuverability when cycling the action. It is often incorporated into builds that utilize a carbine gas system, making it a solid choice for those looking to create a reliable and powerful .458 SOCOM setup.

Specifications

MPNUPUR-3A
Receiver TypeSlick Side
Caliber.458 SOCOM
AssemblyComplete
PlatformAR-15

Available Merchants

Price Alert

Log in to set a price alert on this product.

No Available merchants at this time.

Build history on GunPartPicker

Builders on GunPartPicker first added the Cross Machine Tool Upur-3A Billet AR-15 Side Charging Upper Receiver - Slick Side - .458 Socom Compatible to a build in February 2026.

Trending upper receivers →

Updated · from real builds on GunPartPicker

Not sure which upper receiver to pick?

We ranked every upper receiver by how often it shows up in real builds on GunPartPicker.

Read the guide: Most Popular AR-15 Upper Receivers →

Check it against the live catalog:

Frequently Built With

The part most often added in each category by the builds that include this one

Radian Raptor Charging Handle & Talon Safety Selector Combo - OD Green

Radian Raptor Charging Handle & Talon Safety Selector Combo - OD Green

Charging Handle$155in 25% of them
WMD Guns 5.56 AR-15 Bolt Carrier Group Without Hammer - NIB-X Finish - Black

WMD Guns 5.56 AR-15 Bolt Carrier Group Without Hammer - NIB-X Finish - Black

Bolt Carrier Groupin 13% of them
Aero Precision M4E1 Complete Lower Receiver W/MOE SL Grip & SL-S Carbine Stock

Aero Precision M4E1 Complete Lower Receiver W/MOE SL Grip & SL-S Carbine Stock

Lower Receiver$234 · out of stockin 25% of them
Triarc Systems Track 2.0 5.56 Mid-Length AR-15 Barrel - 14.5"

Triarc Systems Track 2.0 5.56 Mid-Length AR-15 Barrel - 14.5"

Barrelin 13% of them
Knights Armament Urx 4 M-LOK Handguard 10.75"

Knights Armament Urx 4 M-LOK Handguard 10.75"

Handguard$285 · out of stockin 13% of them
Rise Armament Super Sporting AR15/10 Single Stage Trigger - Flat - Dtom Special Edition

Rise Armament Super Sporting AR15/10 Single Stage Trigger - Flat - Dtom Special Edition

Trigger$108in 13% of them

Build Configuration Breakdown

Aggregated and anonymized data showing how builders use this product

Gas System

50.4%
Mid-Length50.4%
Carbine25.9%
Pistol11.1%
Rifle11%
Blowback1.3%
Other0.3%

Review this product

Share your thoughts with other customers

Be the first to review

No reviews yet. Be the first to review this product!