Its realistic niche is for a designated marksman or a hunter working from a blind.
The rifle I tested was a combination of all three variants offered by Aero Precision. It came with an adjustable Magpul CTR stock designed for the 16-inch carbine, a 15-inch forend for an 18-inch midlength rifle and a 20-inch barrel for a full-length rifle. The goal was to have a relatively handy weapon yielding maximum muzzle velocity. A variable-length stock allowed adjustments for various shooting positions and for body armor. Of the two colors available, I chose the flat dark earth cerakote, mainly to reduce the gun’s visibility and its tendency to warm up in direct sunlight during hot Tennessee summers. The edges of the receiver and the forend have all been carefully chamfered and smoothed, making gloveless handling comfortable. Extensively ventilated KeyMod handguards with a full-length Picatinny top rail proved well suited for field use, requiring only a short rail segment up front for the bipod, or a direct KeyMod bipod stud. The stock offered a quick-detach socket on both sides, and the QD rail-mounted receptacle for the front of the sling completed this field-ready rifle.
In cold weather, the all-metal forend would be insulated with rail covers, while in warmer weather, free air flow around the barrel would take priority. Due to the long barrel, the rifle starts out front-heavy, but adding a scope and a full 20-round magazine brings the balance to the front of the magazine well.
In keeping with the intended use of this rifle, I put a 1-6x Vortex Razor HD scope on it. With the optic set to six power, the M5E1 can be used to engage goblin-sized targets out to 600 yards from a bipod or an improvised rest. At intermediate magnification, it’s excellent for unsupported shooting. And at true 1x with daylight-bright reticle illumination, it works as an expedient red-dot sight for tracking motion. A rifle-length barrel with a flash hider keeps muzzle flash from showing up in the field of view, even in low light. The same length and the attendant inertia keep the muzzle rise to a minimum, so shooters can spot their own targets through the scope at all magnifications. The recoil is negligible, allowing full concentration on marksmanship without concern for the kick.
The rifle functioned reliably with over a dozen types of ammunition, from steel-cased ball to hunting soft points and match hollow points. The trigger is smooth during take-up, with a crisp breakpoint but still at military standard weight. Running it in winter gloves, I came to appreciate it for the tactile feedback it provided. The enlarged integral trigger guard helped make gloved use safe.
My M5E1 was test fired from a rest at the factory on my request, grouping around 1 minute of angle with Federal 168-grain Gold Match ammunition. All of my testing was conducted by a former Marine Corps rifleman under less formal conditions from sandbags or from a Lead Sled, usually with some crosswind.
The shooters remarked that they considered the rifle capable of better precision than it demonstrated, though I am convinced that 0.75 MOA is quite respectable, especially when the limitation of the six-power scope is considered. The barrel twist rate is 1 in 10, optimal for 175-grain bullets, while the older 1-in-12 standard works fine for the 168s. For short-range plinking or CQB training, the difference in mechanical accuracy would be of negligible importance, but heavier bullets would work best for deliberate long-range precision work. With initial muzzle velocity around 2,500 feet per second, most 175-grain loads stay supersonic out past 1,000 yards – well outside of the optical range of our setup.
The fit and finish of the rifle are excellent. Internals showed almost no visible wear after the first 400 rounds. While the lower has a threaded opening for a tension screw, I found it unnecessary because play between the lower and the upper was already negligible. I would have preferred an extended charging handle latch, but that’s an easy fix.
The rifle weighs 9.6 pounds empty, on par with an M1A match or FN FAL. Loaded and scoped, it tips in at 13.6 pounds. Its realistic niche is for a designated marksman or a hunter working from a blind. Despite the weight, the gun travels well slung, thanks to the absence of any protrusions. The M5E1 is an evolutionary improvement on the basic AR10 theme, and is a very enjoyable to operate and unfailingly reliable. With the recent price drop bringing the complete gun to the $1,300 to $1,600 range, depending on the variant, it is quite competitive with other precision alternatives. And that has long been Aero’s chosen field, good performance at a reasonable price. ASJ