AR Sponsor
Posted: 4/6/2026 11:29:15 AM EDT
|
I am checking compatability of our new Ripley Rail with a number of piston systems and just need two dimensions. If you have any of the following piston driven AR-15 uppers, can you take the forend off and measure the distance from: 1. The top of the picatinny rail to the top of the piston rod. 2. if there is an easy way to measure from the top of the piston rod to the highest point on the piston gas system (i.e. top of the gas block, and/oror largest diameter of the piston rod if it bulks up larger than the part that goes into the upper receiver) I already know the Superlative Arms system works, and that the POF does not, but would like to check these systems: LMT Caracal HK 416 / MR 556 / BRN-4 Adams Arms Any help you can provide would be appreciated! |
Your best source for bullpup upgrades including the Hellion, Tavor, and AUG! www.manticorearms.com
|
Originally Posted By goer001: I have an older AA kit with the railed gb. If you want measurements lmk, but I assume you are wanting measurements from the newer low profile. @goer001 Actually being they still offer both, dimensions of the older railed one would be super handy! Sven Manticore Arms |
Your best source for bullpup upgrades including the Hellion, Tavor, and AUG! www.manticorearms.com
|
For gas blocks with a rounded top, it might be easier to measure from the top of the rail to the top of the piston rod, the diameter of the rod at that location, the diameter of the gas block on the same plane as the rod axis, and calculate the gas block height that way. Also, you're probably already familiar, but the Hk, and maybe Caracal, use a taller receiver/rail and slightly higher and larger diameter rod. I have legacy MR556A1/legacy 416 blueprints if needed. ETA: from the MR556A1 blueprints, from bore to rod centerline is 20.5mm, bore to top of rail is 37mm, GB width at piston is 14mm, so GB is 27.5 above bore and 9.5mm below rail. |
|
Originally Posted By EzGoingKev: Do you know those guns run a proprietary rail system that is taller than a standard AR? Originally Posted By EzGoingKev: Originally Posted By Manticore_Arms: HK 416 / MR 556 / BRN-4 Do you know those guns run a proprietary rail system that is taller than a standard AR? Yes, but our Patent Pending Ripley Rail mounts to the picatinny of the upper receiver and has plenty of space in the forend, so it couldn’t care less  
|
Your best source for bullpup upgrades including the Hellion, Tavor, and AUG! www.manticorearms.com
AR Sponsor