I used a lot of FlySky remote both air and ground and owned FS GT3B and GT3C it can easily passed 260 ft for ground models. I did learn something why some might get short range but you can easily troubleshoot by doing below check list.
- Open the receiver case, make sure the antenna grounding is soldered to the PCB board.
- Make sure the receiver antenna is parallel to TX antenna.
- Keep the receiver and antenna away from ESC and RF noise from servo and brushed motor.
- Make sure ESC's BEC supply steady 5V current to receiver.