Product Review: Ultramag .50 BMG Upper Kit for AR-15, by Michael Z. Williamson

I recently tested the Ultramag .50, manufactured by Safety Harbor Firearms (SHF) of Florida.The Ultramag .50 is a bolt action, side-fed magazine, .50 BMG upper that uses the AR-15 lower and trigger group. The two big advantages to this setup are that [in the US,] the Ultramag .50 [barreled upper receiver] requires no paperwork to purchase, and is not on record as a large caliber weapon, since it is bought strictly as “replacement parts.” As far as anyone is concerned, you own an AR-15, which can be more discreet if either purchased privately, or by using a forging such as this and drilling the five holes required to legally manufacture your own “single shot” lower (though the Ultramag is magazine fed).

The lower need not have a bolt catch, disconnector or buffer assembly. It only needs the hammer, trigger and fire selector. A magazine release is not needed, but I believe a flush fit 10 round magazine body filled with lead would help reduce recoil, though I have not tried this yet. I did equip the lower with a MagPul PRS adjustable stock in lieu of the factory stock. The kit as tested included: 29″ barrel with fluting, 5 round magazine upgrade from 3 round, an extra 5 round magazine, back up iron sights (BUIS) and carrying handle. I opted to use an adjustable Harris bipod, not the fixed length bipod from Safety Harbor, though this was for personal preference. I’m sure their factory bipod is quite sturdy. Safety Harbor Firearms includes a heavier hammer and spring and an anti-walk hammer pin with the kit. List price for this kit is $2,595. It’s possible to save quite a bit with less options. While they do offer 18″ and 22″ barrels, those have always seemed too short for .50 BMG to me, since it was designed originally for a 36-40″ barrel. They told me delivery would be 8-10 weeks, and it arrived right at 9 weeks, in a professionally fitted cardboard box within a box, instructions for changing the trigger group, a contact number for support and a catalog for accessories.

Fit, finish and operation of the Ultramag .50 can be described as flawless. One of the magazines had a very minor ding, possibly from shipping, that made it a bit sticky. SHF said to send it back and they’d replace it at once, no questions asked.

I mounted a Smith & Wesson 4-12 X 40 scope on the integral rail. This was previously on a different rifle and rail, and my first shots were about 12″ low at 100 yards. Shooting was very consistent, and once I got zeroed the bullets went exactly where the crosshairs were, every time. This was only a warm up, and I didn’t get to shoot to any longer ranges to do a full shooting report. One of the disadvantages of flat Eastern states is finding a rifle range that will allow a weapon this powerful. I have to drive almost two hours to reach one. Recoil with the 8-chambered muzzle brake is comparable to a 12 gauge shotgun. I do recommend a recoil pad and a good shoulder seat with the stock. Seating it a little high can sting. I recommend Loctite for the scope mount—every two rounds was enough to loosen the mounting screws to where the mount would wobble. This is a problem with the scope rings that I acquired separately, which were not part of the Ultramag kit.

The .50 BMG round holds the record for sniping at 2,430 meters, and at ranges not much less can easily disable an engine or other heavy equipment. At $3.50-$7 per round and 20+ pounds, it’s certainly not a close in or primary survival weapon. However, for defending the approach to a remote retreat it’s just about the most accurate and powerful round available to civilians in the US. – Michael Z. Williamson