[MetaEngineer]

I would urge you to not run 1:1 shooter with a 775 or 775pro. The motors don't have enough torque for this and will be overloaded. During prototyping, we overheated a 775 that way running an 6 inch single wheel shooter. It pegged our power supply current limit at 30 amps at 10 volts for 300 watts. Launch power actually seemed less than same motor with a 3:1 versaplanetary, which took 15 amps at 12 volts for 180 watts.

A 775pro with 3:1 versaplanetary outperformed both by a wide margin. I measured 5340 RPM at the wheel, so 16020 RPM at the motor. This is near the motor's peak efficiency, so motor heating is not an issue. The versaplanetary gets hotter than the motor due to the extremely high RPM. Current Draw was 16 amps at 12 volts for 192 watts, though the analog ammeter may not be super accurate. With the right compression but otherwise imperfect mounting, this setup launched boulders more than the required distance.

The suggestion of a CIMile for 2.41:1 would work, and I estimate you'd get maybe 6800 RPM at the wheel. External 2:1 reduction with chain or belt should work too, resulting in maybe 8000 RPM. I'd be curious to hear what actual wheel speeds you achieve. Keep an eye on temps and beware wheels and tread material coming apart at high speed.