Re: IMR 4895 Metering
You'll have to try and see but I'll bet you'll find you have half a grain of variance. You can live with that if you stay well under max or you can throw, weigh and trickle every charge and return it back to the press.
Some guys polish the funnel and take a taper reamer to the powder drop tube to avoid powder bridging tendencies.
Me, I have a 550 and I gave up with stick powders on the dillon. I'll just go through my preps on the single stage for my "good" ammo. For my plinking loads I'll use the dillon and ball powder like BLC2, W748, or WC844 and the consistency is very good. (I polished my measure interior with a dremel but never touched the dillon powder drop tube)
For IMR 4895 I use the uniflow and toss a couple tenths light and trickle up.
ETA Bridging is a serious issue. if you get a bridge in the drop tube, you will drop a light load which is no big deal. The next one is the whammo load, it'll have all the extra that was stuck which may leave you with god knows how much over loaded....5 grains, 10 grains, 20 grains. Scary stuff!