I have this Adams Arms upper Adams Arms - Standard 5.56 Midlength I'm trying to figure out which quad rail hand guard i can swap out to that will fit this upper either drop in or free float, prefer one I can do myself. I own all the AR tools needed for basic work, I just want to make sure I get one that fits so I will not have to go by trial and error and end up returning it. Their FAQ's show the hand guards that are compatible, but I know we have folks on here that could easily answer which one would be good to go. I'd like to add my sling to this rifle and I do not see a way to do that with the current hand guard for the 2 point sling. I also like the looks of the quad rail as well . Thanks This is the list of handguards we currently know will work with our system without any modifications, this list will be updated as more handguards are discovered to work with our system: The Free Floating or Drop In rails available on our website Samson Star-C Samson Star-C- EX-P Samson Star-M Samson Star-M- EX-P Samson Star-R Samson Star-4 Samson Star-4-DI Samson Star-4-EX Samson Star-DI Samson Evolution Series 4 EX Samson Evolution Series 7 Samson Evolution Series 7 EX Samson Evolution Series 9 Samson Evolution Series 9 EX Samson Evolution Series 12.37 Daniel Defense Standard Length Omega Rails Daniel Defense Standard Length Lite Rails Daniel Defense Standard Length Omega X Rails Daniel Defense 9.5 FSP Lite Daniel Defense 12.5 FSPM Lite Daniel Defense EZ Car 7.0 Ergo Grip AR Z Float Ergo Grip AR Z Rail Midwest Industries Gas Piston Two Piece Free Float Forearm Arms #50 Bi-Level S.I.R. System Magpul MOE handguards (most recent version cut to accept gas pistons) Troy Industries Drop In Carbine (Mid length and Rifle length require removal of handguard tension screw and arm) Troy Industries TRX Battlerail Extreme 9" and 7.2" PRI Gen III Delta Carbon Fiber Forearm Newtown Firearms Modular Free Floating Carbine Rail The modified M4 style handguards provided with our standard system Wanna kill these ads? We can help!