Ruger AR-556 MPR 5.56 NATO
Model: 8514
Ruger AR-556 MPR 5.56 NATO
Model: 8514
Full Specifications
About This Firearm
Ruger's AR-556 MPR stretches the standard AR-15 formula with an 18-inch cold hammer-forged barrel, a Ruger Elite 452 two-stage trigger rated at 4.5 lbs, and a full-length M-LOK free-float handguard. At 108.8 oz unloaded, it is one of the heavier rifles in this segment, but that weight sits forward on the 18-inch barrel and helps settle the rifle during sustained strings of fire. The 1:8" twist rate stabilizes everything from 55-grain training loads to 77-grain match bullets, and the 7075-T6 receivers with Type III hard coat anodizing match the material spec found on rifles that sell for considerably more.
The included Magpul MOE SL stock and MOE grip are ready to use out of the box, though the flat-top upper ships without sights. Owners who plan to run an optic from day one will appreciate the clean rail, while iron-sight shooters will need to budget for a set of flip-ups. The Ruger Radial-Port flash suppressor on the 1/2x28 threaded muzzle is functional but easy to swap for a brake or suppressor mount.
Where the MPR earns its keep is at distances past 200 yards. The longer barrel squeezes roughly 50-75 fps more velocity from the same ammunition compared to a 16-inch gun, and the two-stage trigger gives a cleaner break for precision work. For shooters who want one AR that handles both range days and the occasional coyote hunt, the MPR does that job better than most mid-tier options.
Best For
Strengths & Limitations
- The 18-inch cold hammer-forged barrel and Ruger Elite 452 two-stage trigger at 4.5 lbs give the MPR genuine precision capability that most mid-tier ARs cannot match with their mil-spec triggers and 16-inch barrels.
- Magpul MOE SL stock, MOE grip, and 9310 alloy steel bolt come standard — parts that many competitors charge extra for or leave to the buyer to source.
- At 38.25 inches overall and 108.8 oz, the MPR is noticeably longer and heavier than standard 16-inch ARs, making it a poor choice for home defense or any role that rewards compactness.
- Ships with no iron sights on the flat-top upper, so buyers who do not already own an optic need to budget for one before the rifle is ready to shoot.
- The single included magazine is stingy at this tier — several competitors in the same bracket ship with two.
Category Rankings
How the Ruger AR-556 MPR 5.56 NATO ranks among full-size 5.56 NATO rifles.
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Frequently Asked Questions
What is the advantage of the 18-inch barrel on the Ruger MPR over a standard 16-inch AR?
The extra two inches of barrel length give the MPR roughly 50-75 fps more muzzle velocity with the same ammunition compared to a 16-inch barrel. That translates to a flatter trajectory and more energy at 300+ yards, which matters for precision shooting and varmint hunting. The trade-off is 38.25 inches of overall length and 108.8 oz of weight, so the MPR is less handy indoors or in tight spaces than a standard-length AR.
Does the Ruger Elite 452 two-stage trigger need to be replaced?
Most owners keep it. The 452 trigger is rated at 4.5 lbs with a distinct first-stage take-up and a clean second-stage break, which places it well above mil-spec triggers in feel and consistency. Competitive shooters who want a sub-3-lb pull will still upgrade to an aftermarket unit like a Geissele or LaRue, but for general range use and hunting the factory trigger is more than adequate.