I have used it on my 200 gr swc used in a .45acp, a 158gr swc used in .38 and .357, and a 255gr fp used in a .45colt.
I use a single stage RCBS rockchucker press, so I am positioning the bullets by hand, but the lube is hard and doesnt wipe off on anything.
On the 200gr and the 158 gr, I shoot as cast. When I lube them, I put about 100 to 150 at a time into a round cardbord quart container, the kind that ice cream comes in. I squirt in about a 2 inch long line over the top. I do not heat or thin the lube, although I do use it in my garage, and in winter its really cold, you could try heating it by letting the bottle sit in a cup of hot water for 10 minutes, I might try it next time. But it works ok even in the cold.
I gently tumble the lube on, this only puts on a really thin coating of lube. I have found if I'm shooting 1000fps or less, this is enough. After I tumble them well, I lay them out on a sheet of wax paper sitting them up on their bases. this is the longest task. Sitting each one up on its base. In winter I set a lamp with a 60 watt bulb about a foot over them to keep them warm over night to dry. the next day I put them in the tuperware container I store them in.
The 255gr I use in the .45 Colt I size. these are used in a hot load about 1150 fps so I also give them a second coat of lube. I give them a light coat of lube like the first batch. After they dry the next day I pump them thru the simple lee .452 sizer. After that I lube them again the same way with another light coat. They come out looking a slight golden color. After they dry over night, they are fine. After shooting 100 rounds of this, I find only a slight streak of leading in the barrel. With the other slower loads, I get no leading at all. The .45colt is fired in a RugerBlackhawk with a 45/8 bbl, and is not a pleasant load to fire a lot, even with rubber pachmyr grips.
I think if you put a thick coat on all at once, they do not dry thouroughly, and might be causing your problem. Try using a really light coat. When I use it, it looks like it is not going to be enough, but a little really does cover a lot of bullets.
The Lee manul says that some users of this lube heat it by sitting the bottle in a cup of hot water. And some actually thin it with something that I cannot remember right now. I am in work right now, I will look it up in the manual tonite and post what they use here.
I hope this helps.