I find that the trick with the Lee throwers is to be very consistent in your action. Yes, sometimes the “feel” just doesn’t feel right, granules of powder get cut or bind in the drum. It all depends on your application, the variation from a “clunky” throw might make fuck-all difference to a plinking load. If I’m just chucking pistol or lever gun ammo together and get that, I’ll just throw a couple of quick charges into a plastic cup to clear it and get back to loading. If it happens regularly, a quick strip and clean, check for burring on the edges, reassemble paying attention to how tight you put it back together, will usually fix the problem.
One thing that I’ve seen blokes do that I believe gives them bad results, ( with any thrower ), is having the arm in the “up” or charging position when introducing the case to the thrower. Any impact or movement of the thrower, no matter how slight, will cause settling of the powder in the drum and give differing charges. I’ve also watched blokes slam the charge handle up and down, which causes the powder to jump, then wonder why they can’t get a consistent charge.
I’ve got a Lyman that is total crap when it comes to throwing consistent charges no matter what I do with it, I bought it “as new” second hand, I reckon I now know why the original owner got rid of it. The adjustment is also over complicated and unnecessary. I’ve used Harrels and not been happy with those either. I have an expensive MVA dedicated blackpowder thrower that I won in the U.S. While it is very accurate, it is slow and tiresome to use and a pain in the arse to change the charge amount.
I suppose it may just be familiarity with the Lee’s, ( talking 10’s of 1000’s of rounds ), but I can quickly set a charge amount and go on to throw consistent lots of 50 in a short amount of time. I can get good results with mine with anything from as little as 3.5gr of pistol powders right through various “stick” rifle powders up to 115 grains of blackpowder. ( I don’t subscribe to the urban myth about static in plastics and blackpowder )