SDM-R Rifle

I am planni9ng to build a SDM-R Rifle (AKA AMU Rifle). MUch of the info I have seen on the internet specifies a 20 " heavy barrle with flutes and a gas manifold secured by 4 set screws with the ability to attach a front sight to it. The pictures I have seen show a rifle with a standard front sight. Can't tell about the flutes. A friend of mine(retired USAF E-8) is a civilian DMR instructoor for the Army. The ones he has seen had the standard front sight and no flutes. He also has talked to the head of the AMU who said they did not build them with barrel flutes. Any other observations? Terry

i believe that these bbls are available from white oak armament. john hollinger makes some great bbls that have all the flutes and adjustment flats milled in. not inexpensive, but really good. chk out the white oak website .

I have one of Johns match rifle barels on my space gun, Excellent barrels! The question is what is the barrel configuration that the Army actuall uses. I have identfied all the components needed to finish the rifle except for the barrel. Right now I am leaning toward a non fluted barrel as it does not appear that the AMU used fluted barrels. Terry

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Originally Posted by LTCJohnston

I am planni9ng to build a SDM-R Rifle (AKA AMU Rifle). MUch of the info I have seen on the internet specifies a 20 " heavy barrle with flutes and a gas manifold secured by 4 set screws with the ability to attach a front sight to it. The pictures I have seen show a rifle with a standard front sight. Can't tell about the flutes. A friend of mine(retired USAF E-8) is a civilian DMR instructoor for the Army. The ones he has seen had the standard front sight and no flutes. He also has talked to the head of the AMU who said they did not build them with barrel flutes. Any other observations? Terry

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Terry, I am a life MMA member and spend considerable time at the AMU. I am building 10 such rifles as we speak so here is the skinny:

The AMU has and does use both fluted and unfluted AMU taper barrels. Most come as blanks from Douglas or Krieger.

The fluted barrel is very difficult to make as the stress relief requiremets for the flute process takes 4+ hours to do on a CNC mill. The only advantage the fluted barrel has is better heat dissapation. The AMU/DMR taper profile is now more commonly used. Extensions are M4.

The rifles are flat top, standard front sight, 20" SS barrel with a .223 Wylde chamber. Finish length 20", bore: .218, Groove: .224, Groves: 4.

Standard A2 stock, Daniel or LaRue floating hand quard. Sights are unit specific but the Trijicon 4x32 TA01 is the most popular. Harris bi-pods are used primarily.

A picture of one is attached. I am second from left, Sgt Grany Singley, Nat Service Rifle Champion is holding the gun and was my coach at Benning this last October.

Just wondering if you had success building your rifle yet?