Something is wrong with your balancing method / technique / equipment if you had to remove 3/8" from any 10x6 prop. Having flown AMA combat for over 20 years and prepping my share of props, there is nothing wrong with removing material from one extreme end. Usually it takes less than a 1/8" to get the job done.
If you are talking about balancing an APC or Scimitar Series wood prop with the pointed tips, then you don't want to alter the shape. I've used sandpaper to balance and re-pitch APCs. It isn't brain surgery, check your results at full throttle while you hold the model. If it runs smooth, then that's all you need.