Extruder slipping?

I've followed the Triffid Hunter calibration guide and got everything moving the correct distances, however whilst extruding the extruder motor (Bowden extruder) makes noise and the gear holding the filament flicks back a step like it wasn't able to feed through properly.The grip between the extruder gear and the filament is definitely strong enough. I have checked everything for blockages and it does extrude but always with this slipping, I know it's not retraction as it's happening whilst simply extruding filament straight down. Any advice for me? I've hit a wall with this, it's my first printer and i'm happy to listen to any suggestions.
My printer is a Sunhokey Prusa i3 with 0.4 print head diameter and a bowden extruder.

Lower your feedrate, if you are absolutely sure that your idler bearing is tigh enough and that your hotend is at right temperature for the filament and filament is coming out of your hotend without any problems, then by lowering your feedrate the clicking will disappear

Check the current going to the extruder stepper. Mine did this when it was under-powered.

Not sure what controller or stepper drivers you are using, but here's the documentation on adjusting stepper current for a Melzi w/integrated stepper drivers.

[reprap.org]

I ended up manually adjusting the potentiometer for the current to the extruder stepper while the printer was printing and skipping. I turned it down ever so slightly, skipping/stuttering got worse, then adjusted it up in small increments until the skipping stopped. I adjusted it downward again until the skipping started, then up just a hair. Extruder stepper runs slightly warm now instead of room temperature. Haven't had any more issues with the extruder stepper since, it does what it is told to now. :-)

Ground yourself and use insulated tools.

-speedeep