It is not the Dillon it is the powder that you chose. Varget is a great powder and I use it for several loads. But no powder dropper is impervious to large stick powder making a bridge once in awhile. I also have a Harrell powder drop, The best made at over $300 just for the measure and guess what Varget will hang up there also. So either polish away or choose a different powder.
Do you shoot all of your guns box stock?? Tweaking is part of the game, And there are many on the 1050s, You will soon find out.\
Hoofy gave you great advice and the place to solve your problem