I am looking to setup an AE M5 on a shorty barrel and wanted to know if anyone is running theirs under handguards. Which free floating handguards are you guys running that allow a recessed fit?
I've got a 8.5" 300 Blackout upper with a YHM handguard that covers most of the QD mount and my Phantom fits inside with room to spare. The handguard was on the original upper and happened to work so I left it that way - looks pretty cool and makes it less likely to grab the can. It should just be a matter of checking inside diameters against your can's outside diameter and allowing some extra.
Any handguard with a 1.7" ID should be gtg. JP, Apex Machine, Seekins, Sampson Mfg are a few options off the top of my head. Many more probably fit the bill. I tried with a KAC URX4 (1.55" ID) but it was too tight. Depending on your rate of fire, grip locations, and how much of the can you cover it's very possible to see a significant jump in the heat you're feeling through the handguard. Just a heads up as you consider the available options...