M16 (AR-15) caliber .223 (5.56mm) full or semi-auto magazine fed rifle. The original issue was designated as the M16A1 and replaced the M14 during Viet Nam. It fired a 55 grain FMJ (Full Metal Jacket) projectile (M193) in a standard weight 1 in 12 twist barrel select fire. Later on after the war it was redesigned as the M16A2 which fired a heavier 62 grain projectile (M855) for greater distance with a hardened steel insert (green tip) for greater penetration on harder targets. The barrel was changed to a heavier 1 in 7 twist to stabilize the longer projectile. The sights were Changed to allow adjustment of the rear sight by thumb screws for windage and elevation marked from 300 to 800 meters. Select fire was changed from semi-auto to burst (3 rounds). I built my gun on the M16A2 configuration using GI parts and using a Bushmaster receiver (Semi-auto only). My barrel has a 1 in 9 twist (Quality Parts). I also have the current issued AN/PVS-4 Night Vision Scope for it, and a military .22 adapter kit. A laser sight is mounted on top of the barrel. I have a 20mm AR15 scope with bullet drop compensator and a night observation sight that I constructed from the eyepiece from a pair of AN/PVS-5 Night Vision Goggles that mounts onto the carrying handle, which is used in conjunction with the laser sight for night time aiming. I also have the GI M7 bayonet with M10 scabbard and M9 bayonet for it.
This is the previous rifle mounted with USGI (Current Gulf War issued) AN/PVS-4 Night Vision Sight
Olympic Arms .223 AR15 type flat top rifle. I built this rifle using an Olympic Arms flat top receiver, fitted with an Olympic Arms ultra-match 24 inch bull barrel. It is fitted with a free floating round hand guard, a JP match trigger and topped with a 4-12 x 50mm mil-dot Tasco scope.. I have used it successfully on groundhogs out to 300 yards using Military green tip M855 ammo.