The OTIS Technology CRS-2-74 and the OTIS FRAK Program

By Christopher R. Bartocci

In May of 2011, the U.S. Army put out a solicitation as part of the M4 Product Improvement for the FRAK or Forward Rail Assembly Kit. This is to replace the outdated M4 and M5 Rail Adapter System that has been in use since the late 1990s. OTIS Technology had earlier put out to market the TRS Rail system. Although OTIS Technology is noted for world class cleaning gear, the company has other areas of expertise as well. OTIS Technology built a research and development center in Phoenix, New York in 2010 where R&D would take place for OTIS to enter new markets. When the Request For Proposal (RFP) came out for the FRAK rail, OTIS Technology was up to the challenge. However, they had less than 6 months to come up with a design that would meet the criteria and be worthy of competing with the likes of Knight's Armament and ADCOR just to name two.

The best way to go about designing a better handguard was to look at what the old one is and how it can be made better. The first thing to come to mind is making the handguard free floating. By free floating the barrel you will not only increase accuracy but increase cooling of the barrel. The other benefit is there is no weight added to the barrel or any force. The weight comes from the gadgets that are put on the rail and weigh it down. This includes flashlights, bipods, lasers, IR pointers as well as thermal/night vision devices. The force is eliminated from the vertical pistol grip not being attached to the barrel to possibly cause the barrel to bend if it got hot enough from the downward force on the grip. This was going to be the approach that OTIS engineers would take. But how to do it?

The best way to attach the handguard to the rifle is to mount it to the barrel nut directly. To get the handguard/rail secure, the delta/slipring spring weld and snap ring are removed from the barrel nut. If you were to try to mount the rail with the delta/slipring assembly on the rifle, you would not be able to get enough bite on the rail to securely attach it. The patent for this type of attachment belongs to Richard Swan, President of A.R.M.S., Inc. OTIS established a partnership and contract with Richard Swan to use his technology to mount the rail to the barrel nut. With the most difficult part taken care of, OTIS engineers were able to develop an incredible rail in less than 6 months. The OTIS rail only used the A.R.M.S. mounting method with some minor modifications. The rail body itself was designed by OTIS engineers to fully meet the specifications put out in the requirements.

One issue was how would you replace thousands of rails quickly, especially if you had to remove the delta/slipring assembly? OTIS engineers came up with a fixture and hydraulic cutter. You would set the upper receiver in this fixture, hit a button, there are upper and lower blades on each side of the delta/slipring that would come together and snap the delta/slipring in two places and pop it off. Then the spring weld and snap ring are removed with a pair of pliers. Then the OTIS FRAK rail would install in minutes. This proved to be a very quick and efficient way to do the conversion. The barrel was not removed nor was the front sight base removed, which can have negative effects on the rifle.

The FRAK rail was manufactured from 7075 T6 aircraft aluminum, the same material as the upper and lower receivers of the M16/M4 rifles. The request required a minimum of 14 rail notches per side, which was met. The handguard is in 3 pieces. The main handguard fits over the top of the barrel and there is a groove in the top for the gas tube. On the inside to the rear you will see the single radial cut in the end of the barrel nut (raised scallop portion) that fits into place. Then the collet is screwed into the bottom of the rear of the rail over the barrel nut. This secures the rail to the barrel nut by two screws. Then the bottom rail is installed in the upper rail and secured by 4 smaller screws. OTIS engineers put this rail through a series of rigorous tests. Fixtures were built to do drop testing, temperature reading, installation timing and so on.

The OTIS FRAK rail was submitted for government testing and did quite well. In the end they did not win the solicitation. However, they have made themselves known to be a threat to some of the biggest names in rail manufacturers. Their engineering staff is capable of producing military grade weapon components. OTIS Technology has since released their FRAK for sale to the commercial market as the CRS rail. The commercial version is manufactured from a less expensive and easier to machine 6061 aircraft aluminum and hard coat anodized black. Currently it is only offered in carbine length but prototypes do exist in both mid length and rifle length handguards. As for military customers, the OTIS rail is manufactured from the stronger and more expensive 7075 T6 aircraft aluminum.

This author has tested for nearly two years the prototype FRAK rail on a custom LMT Defender rifle. This prototype is identical to the current production with the only differences being this one is manufactured from 7075 T6 aluminum and there are two QD attachment points on the rear left and right side of the handguard. Over these years more than 5,000 rounds have been fired both semi- and full automatic. The handguard has never come loose and the laser sight returns to zero every time it was removed and put back on. A sample of the current production of the CRS commercial version was obtained and was installed on a LMT upper receiver. An EOTech sight was attached to the rail, zeroed at 50 meters and removed. Then it was reinstalled with full return to zero performing as advertised.

OTIS Technology has made several departures from just cleaning kits over the past couple years. They are branching out into different areas of the firearms industry including government procurements. This rail is but one example and although it was not adopted, it was a success. The rail is military grade and has been tested to the highest standards by a group of engineers who left nothing to chance. This rail will compete with any rail out on the market among the top tier manufacturers.

This article first appeared in SmallArmsReview.com on February 7, 2014


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