I use choppers for all the fletching I do. They do take some practice to get consistently good results. I feel that the base grind on the feather makes a huge difference in how well the chopper works. I get the worst results with Trueflight feathers and the best with Gateway and the feathers that Sagittarius Archery sells.
Guy
I get the best chopping results when the bases are ground narrow. Thick doesn't seem to matter much but a wide base can and will fold over as the blade comes down and that will change the way the feather itself cuts. Narrow bases don't fold. That's why I've always liked Gateway feathers and those that Sagitarrius Archery sells, they both have narrow bases and I get consistently good chops on them.
Guy