A barrel shroud with rails is really your best option. It will allow you to place a grip in a much more comfortable location.

__________________

A5, 12" PPS Brass (.690) with Apex tip, Tacamo HK 416 shroud, Tacamo AK-47 Sight Cover, JCS Gold Powertube, E-Grip (APE), Core CQB Wire Stock w/ RVA, Palmer Inline Stabilizer, Lapco Cyclone Ratchet, 450 round Hopper, 48 oz CO2 with remote line