SIONICS 12.5″ Upper Receiver Group

(1 customer review)

from: $59995

SIONICS 12.5″ Upper Receiver Group – Base price includes

SIONICS 12.5″ Medium Contour Chrome Lined Barrel

SIONICS 11.8″ Handguard

Don’t forget to add your Bolt Carrier Group, your Charging Handle and your Sights!

Estimated Completion Date May 2, 2023 - May 5, 2023
SKU: S-UR-N-ACH-NS-125 Category: Product ID: 12739


Base Configuration:

Upper Receiver: 7075 M4 AR15 Style 5.56mm NATO
Barrel: SIONICS 12.5” Medium Contour, 41V50, NATO Chamber, 1:7, 5R Rifling, Chrome Lined, Air-Gauged, Radiograph and MP Inspected
Gas System: Carbine-Length – Direct-Impingement
Muzzle Device: A2 Flash Suppressor
Hand Guard: SIONICS 11.8″ M-LOK with 5-Slot Picatinny MLOK Adapter

Optional Installed Add-Ons:

Bolt Carrier Group: Either the SIONICS Phosphate Coated BCG or the SIONICS NP3 Coated BCG

Charging Handle: Radian’s Ambidextrous Raptor Charging Handle

Sights: Either Magpul MBUS or MBUS Pro Flip-Up Iron Sights

Product Features

1 review for SIONICS 12.5″ Upper Receiver Group

  1. Ralph Bartolome (verified owner)

    This upper is extremely underrated and slept on! My “go-to” was my 11.5” Geissele Super Duty and now it’s this (12.5” SIONICS)! Pair this with an A5 buffer system and this thing runs so smooth! Amazing guys to work with and we’re also very helpful. A great company with great products and customer service to match.

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Here at SIONICS, we test fire EVERY BCG, upper receiver group, and firearm.

Our test firing process is simple:

  • BCGs get 5 rounds of M193 and another single round in a separate magazine to ensure function, ejection pattern, and lock-back.
  • All upper receiver groups and firearms get 7 rounds of M193 and another single round in a separate magazine to ensure function, ejection pattern, and lock-back.

SIONICS handguards are incredibly rigid and the inherent design features ensure anti-rotation. Through rigorous testing both by SIONICS and the many LE agencies using SIONICS rifles we can ensure zero retention when using IR/VIS aiming devices.

SIONICS handguards feature QD attachment points at the forward and rear 3 and 9 o’clock positions. SIONICS QD receiver sockets are anti-rotational.

The SIONICS barrels utilize 5R Rifling. 5R Rifling helps fight bullet failure due to a softer angle on the sides of the lands vs. conventional style rifling that utilizes 90° corners of the lands, which is a very hard edge.  Furthermore, with 5R, you have 5 lands in the bore of the barrel.  The odd number of lands does not directly oppose one another. The combination of these two things deforms the bullet less – less distortion to the bullet jacket when the bullet makes the jump from the case into the rifling.  This helps fight bullet failure and increases the inherent accuracy of the barrel.  Lastly, the gentler edges of lands on the 5R Rifling allow easier cleaning of the bore.  The 90° corners of conventional rifling make it harder to reach lead and other contaminants when cleaning.  The softer edges of the lands on 5R Rifling allow for a much more thorough cleaning process.