Aimrite�s Competition Carbon railgun was designed to accommodate heavier twin 5/8� (16mm) bands while firing the more rigid spring steel European notched shafts. Shaft sizes include 6.6, 7 and 7.5mm. The Competition's barrel has a wall thickness of .078� (2mm) of high grade carbon fiber. This reduces flex dramatically when under heavy power which in turn results in more energy transfer to the spear shaft and most importantly, a more accurate shot. The shaft rides atop Aimrite�s integral track which also adds strength and rigidity to the barrel. Each gun is individually hand assembled and tested with all precision engineered Aimrite components. Guns come "ready to use".