The CMP is auctioning of an XM-3 sniper rifle.
Up for auction is a DEFENSE ADVANCED RESEARCH PROJECT AGENCY (DARPA) XM-3 Sniper Rifle used by the United States Marine Corps. In mid-2005, DARPA worked with Lt. Col. Norm Chandler’s Iron Brigade Armory (IBA) to field items to expeditionary units in Afghanistan. Since they already had a great working relationship, DARPA contracted IBA to build and test lightweight sniper rifles that incorporated the improvements the snipers desired in combat. The mission was to be lighter and smaller than the existing M40s, while having better accuracy, clip-on night vision that did not require re-zero, better optics, and better stock, and it had to be suppressed. The barrel had to be short enough to allow maneuverability yet long enough to deliver a 10” group at 1,000 yards. If the barrel was too heavy, maneuverability would decrease, yet if the barrel was too light it would only be able to shoot a few rounds before the groups started to shift due to barrel temperature. IBA tested a number of barrel lengths, ranging from 16 to 20 inches and in different contours. Each rifle with a different length was assigned an XM designator starting with XM1 through XM3. In each case, everything on the prototype rifles was kept the same except the barrel. During the final phases of testing it was found that the 18” barrels had no issues keeping up with their longer 20” brethren. The final barrel length was set at 18.5”, and the contour was a modified #7. The straight taper on the barrel was only 2” vs. 4” and the overall diameter at the muzzle was .85” vs. .980”. This helped reduce a lot of the rifle’s weight while not negatively affecting accuracy or effective range. A number of the groups at 1,000 yards were <1 MOA.
The Marines of I-MEF were the first to field test the rifles at Camp Pendleton. Shortly after I-MEF took receipt of the XM-3s, the first units in II-MEF took receipt of theirs. By mid-2006 there were dozens of XM-3s in Iraq. There were 52 XM-3s made.
The Chandler brother wrote a pretty detailed article about the XM3 in an issue of Precision Shooting Magazine that I have around here some where. They used the most well proven and toughest components they could find at that time. To make the gun stronger , they even developed it as a single shot bolt action, There is now internal or detachable magazine and no provision to add one. It was a big hit with users at the time. But it didn’t take long to realize it was not that great of an idea for sniping on the modern battlefield.