How hot does your hotend go, also e3d hotends have 2 versions lite6 and v6. the lite6 can only handle temps up to 245 celcius with proper cooling, if you go higher than this you can melt the ptfe tube (bowden)
the v6 uses a heatbrake, this seperates the ptfe tube (bowden) from te hotend and therefore can handle themps up to 400 celcius also with proper cooling
so check cooling of your hotend, check the temps and check your filament specifications, what temps are adviced to print with,
if everything turns OK and still having issues with jamming, try turning your hotend temp up with 5 degrees and try again.
hope this helps a bit