I've had wierd success with extruded powders in throwers & have yet to try 'em in my 550 .... time'll tell.
I've a Reading thrower that does very well with the finer stuff, runnig a single stage use, but when doing extrudeds, I'll set the thing to throw, sometimes 2 grains low, & use a powder trickler.
Same-same using Lee's powder scoop kit &, at the low end, use the trickler to fill the pan to the right weight.
Sometimes that's the best you can do.
I'd appreciate any further input too, other than a change of powder - & then again, I'd appreciate that info too.
Never used some of the latest powders that seem to flow ... stuck in the early 70's I am ....
(... which is no help at all for a progressive - edit = time delay due to a dying PC .... )