06-19-2014, 05:45 PM
Good article. I would add that the filth from carbon fouling is placed in a different location on an op-rid driven gun, versus DI.
Colt made a prototype/test op-rod AR15 back in 1968 called the Model 703. It was deemed inferior to the standard AR15 across the board.
![[Image: Colt_model_703_piston_AR_prototype_zps93b1cf04.jpg]](http://i6.photobucket.com/albums/y232/Alpha-Romeo3/Hunting%20Download/Colt_model_703_piston_AR_prototype_zps93b1cf04.jpg)
![[Image: colt703b.jpg]](http://home.comcast.net/~cjan99999/colt703b.jpg)
Colt made a prototype/test op-rod AR15 back in 1968 called the Model 703. It was deemed inferior to the standard AR15 across the board.