What exactly is the difference between the various op-rod choices?

  1. What exactly is the difference between the various op-rod choices?
  • The 16” Carbine (See photo below) is now the workhorse of the AR-15 community. The op-rod on the bottom is a regular Carbine-length, which measures 6 3/8”. The modified carbine op-rod is exactly the same length, but the shaft (the black portion) is 2 5/16” long while the regular Carbine shaft is 2 25/32”. The modified rod allows for more travel when using a free-floating hand guard’s wider barrel nut. You will need at least 1 7/8” ID clearance for the piston chamber to seat properly under your hand guard.
  • The 18” Mid-Length op-rods measure 8 3/8” total. We have discontinued the Mid-Length standard op-rod. 
  • The 20” Rifle-length op-rods (not pictured) measure 11 3/4” in total length. We have discontinued the Rifle standard op-rod.