Bushmaster ACR Caliber Conversion System Comes to Market

by
posted on October 11, 2018
** When you buy products through the links on our site, we may earn a commission that supports NRA's mission to protect, preserve and defend the Second Amendment. **
finalacr-beauty-shot-1.jpg

After eight years of anticipation, the Bushmaster Unicorn, also known as the ACR caliber conversion, has finally hit the market. This caliber conversion system for the ACR, a platform that offers fully ambidextrous controls, improved ergonomics, an ultra reliable gas -piston operating system, and tool-less configuration and caliber adaptability, is promised to be the first of many caliber options. For now however, these conversions will be offered in .450 Bushmaster, and 6.8 Rem. SPC II. For a complete list of the options now available, please see the chart below:

Product Specifications

Product

Order #

Barrel

Magazine Capacity

2018 MSRP

16” .450 Bushmaster ACR Conversion

90023

16” FNC Treated 4150 CMV, 1:24”
twist

5 Round Polymer

$699

18.5” .450 Bushmaster ACR Conversion

90024

18.5” FNC Treated 4150 CMV, 1:24” twist

5 Round Polymer

$699

16” 6.8 Rem. SPC II ACR Conversion

90028

16” FNC Treated 4150 CMV, 1:11” twist

25 Round

$699

 

Latest

Ukraine Operators
Ukraine Operators

Ukraine Operators Use Drone Round to Defeat UAS

Ukrainian operators recently tested and defeated drones with the Drone Round—a purpose-built cartridge that requires no firearm modifications, no new equipment and no additional training.

From The Counter: The Gun Store Prime Directive

When visiting a firearm retailer, know when it’s appropriate to interject, and when you should keep quiet.

Red-Dot Occlusion Training: A Performance-Booster for You & Your Optic-Equipped Handgun

Red-dot occlusion is a passive technique that shooters can use to remain target-focused, thereby speeding up their performance with optic-equipped handguns.

New for 2026: Dead Air Nomad Ti Over-The-Barrel (OTB) Suppressor

The Dead Air Silencers Nomad Ti OTB is designed to be a compact and lightweight suppressor for the backcountry hunter.

I Carry: Diamondback SDR in a Galco Hornet Holster

For our latest "I Carry" episode above, we paired the six-round Diamondback SDR DA/SA snubnose revolver with a simple leather holster from Galco, along with one of the latest EDC flashlights from Streamlight.

The Armed Citizen® May 8, 2026

Read today's "The Armed Citizen" entry for real stories of law-abiding citizens, past and present, who used their firearms to save lives.

Interests



Get the best of American Rifleman delivered to your inbox.