Powder Flow

 Ball/spherical powders do meter better than extruded powders, by virtue of their short dimensions. However, the difference isn't significant when it comes to shooting, as extruded powders are more forgiving of minor weight fluctuations. With extruded powders, it helps to slow down the movement of the powder bar, so that it takes about one full second to move the bar from one side of the measure to the other.

 Keep in mind that all powder scales, regardless of being digital or beam, are accurate to +/- .1 grain. And the internal volume of the individual cases will vary more than that.

For 55 grain bullets I personally use H-322, and for 70 grain and heavier I use RL-15, both short-grained extruded powders. I have found it is easier to find a sweet load with the extruded powders in general than with ball/spherical powders.

I have also exprienced the same issues as sublimaz41.  But what I have observed, is a problem with vibration.  If you cycle out the current rounds, ie: Powder fill, bullet seat, and crimp. and then restart with size and primer and then powder fill, I have noticed that with extruded powders, I can have a +/ 3.0 grain change on the first load.  Now if I dump the first load, after cycling the machine, every thing is fine.  Subsequent loads (I have tested over 100 at a time) loaded powder within +/- .2.  Now for rifle rounds this is no problem.  But there seems to be a vibration that ends up depositing more powder when using extruded powders.

I have directly bolted my 550 to a 4x4 bench and used in on a 2x2 bench with the same issues.

Maybe we can get an answer to this problem.

Roger - Anm2_man     

Yes, there are differences in consistency between the different powder types.

Fine-grained ball powders typically meter best.
Long-grained extruded powders have more variability.
Flake powders generally fall somewhere in between.

This general behavior is seen with all powder throws, not just the Dillon powder throw.

I can almost always choose a ball or fine-grained extruded powder that is ideal for my needs.