The test rifle was set up in two different configurations for field testing—a simple lightweight carbine and designated marksman rifle (“DMR”). For use as a defensive carbine, Aimpoint’s Comp4S was the optic, probably the best combat red-dot ever made. Currently issued as the M68 to our troops, it has much less tunneling effect than the T series. The dot is the least “sparkly” Aimpoint uses and includes an ARD reflector. Its mount is rock solid and the AA battery provides run times measured in years. As a DMR, scope duties came from a Leupold Mark 4 MR/T 2.5-8x 36mm being used on another test. Currently used on the Marine Corp’s’ M38, the TMR reticle provides holds and the M2 77-grain BDC turret is matched for MK262 Mod 1 ammunition. Geissele’s Super Precision mount keeps it rock solid.

Range Time

Accuracy on this rifle was a bit surprising to me. Groups at 100 yards with both the 77-grain TMK and Black Hills 55-grain TSX were between 0.50- and 0.60 inches. Even the Barnes AR practice ammunition was under an inch. Not much changed at 300 yards with groups all hovering at or under three inches. Ten-shot rapid fire strings at 300 yards all stayed on the ten-inch steel with no visible elevation change due to barrel heating. As much as I tried to get this Gunner barrel to start climbing under heat, it just would not do it. Maybe under full-auto fire conditions, but push anything but a bull barrel that far and you’re going to get that . . . simple physics.  Nothing anyone would do with this in the real world seemed to do anything to adversely affect accuracy.

Initial testing was completed between classes while teaching at Gunsite Academy. It allowed me to stretch it out on the Military Crest from various positions amongst the trees and scrub. Most testing was completed using the Leupold, although a couple runs were made with the Aimpoint. This is honestly where the weight loss showed its most promise. Running up and down the trail it is noticeably lighter. Moving in and out of, around, and through the branches was much easier compared to a standard rifle I was testing at the same time. After the third or fourth run the weight difference became abundantly clear. Using the Aimpoint and iron sights was even better, with no loss of effectiveness out to 300 yards. After a couple weeks running this rifle (and me) along Military Crest and the Scrambler, the value of an ultra-light AR was clear.

Back home the Robar was used during two other articles being completed at the time.  One was on lightweight ARs in general, and the other on the value of one handed shooting. The real world is not square and void of obstacles allowing, you much of a stance or the use of both hands. Running the PolymAR 15 Ti single handed was almost a revelation. Maneuvering through obstacles, opening doors, curtains, pushing people aside or protecting loved ones with your off hand holding a rifle is hard work. It’s the same experience as clearing buildings, holding a rifle in your shoulder for even moderate periods of time can be tiring. The difference using this rifle was huge. Testing under these conditions only solidified my decision to make this my primary training and testing rifle—it’s just too easy on the shoulders and back without losing any accuracy or reliability.   

Other Thoughts

Two or three different muzzle devices were tried during testing, but none were better than the BCE, especially when you consider how little it weighs. Blast at the shooter is minimal at worst, unnoticed most of the time. Same on the sides, and it does a solid job of managing recoil and muzzle movement. Keeping it light at the muzzle helps with swings between targets and this keeps it very fast, without killing you while shooting it. 

Lancer, Brownells, Magpul, BCM, and the supplied Tango Down magazines all worked in 10-, 20- and 30-round capacities. Insertion was the same as any other AR, all dropped free, and no stoppages or malfunctions occurred with any ammunition used.

My age and eyes almost demand optics these days, and that is a really strong point for this rifle. Even with my additions and the optics the weight was still at 6 pounds, less than some standard ARs weigh bare. That is huge in the long run since you get the advantages without the added weight. It really allows you to properly equip your AR-15 without turning it into a weight for working shoulders.   

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