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

Springfield New Coas 01
Springfield New Coas 01

Making the A-Cut: Springfield Armory's COA-Ready Operator, TRP & DS Prodigy Pistols

Springfield has already released a COA-ready version of its Echelon earlier this year, and the new models will bring the A-Cut to the company’s hammer-fired handguns, including the 1911 Operator, 1911 TRP and 1911 DS Prodigy.

Skills Check: Snake-Eyes Drill

Our drill this month trains you to form a stable firing platform early enough to gain optimal control before the shot breaks. Timing is of the essence.

A Memorial Day Conversation With Grey Team

Grey Team was founded to help armed services members and veterans with the physiological impacts traumatic brain injuries, post-traumatic stress disorder, chronic pain and more.

42 New Handguns for 2026

Within the entire firearm marketplace, handguns continue to be some of the most popular offerings, and for good reason.

The Armed Citizen® May 25, 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.

President’s Column | Hope Is Not a Strategy

It was great meeting so many enthusiastic and supportive NRA members at the NRA Annual Meeting in Houston. Your words of encouragement and suggestions are propelling your NRA 2.0 forward.

Interests



Get the best of American Rifleman delivered to your inbox.