I have the Lee REAL Molds 54 cal.along with a couple of Lyman. I use a Lee production bottom pour pot.I have a couple questions.
What temp. do you bring your lead to?
What practice do you use to maintain consistent bullets?
I see different sizes in the same batch. Haven't measured but see it when loading.Some fit tighter than others.
Also,what do you guys use to clean and lube the molds.I have noticed that the spur cutter gets tight to move.

I clean my moulds with dish washing soap and a tooth brush " just for that job". Then I heat it up on a stove to get it hot and dry, I use a birthday candle to lube the cutter. I have a drip o matic lee production pot. To be honest the bottom pour will not fill the mould fast enough. I laddle big bullets. I also try to squeeze the handles the same every time.
If your seeing different sizes your mould is not filling out. I am betting on a couple things. The lead and mould are not hot enough, AND the bottom pour is not flowing fast enough and if your not already doing it keep the mould close to the spout. If it were me I would laddle those big bullets. Ron

+1 on ladle pouring.
I really can't image the bottom pouring those big bullets. the heat needed for the bullets to pour right. I am making some 380gr 54cals tonight, I will take some temps when I get good looking bullets made.

I spray my moulds with moly or smoke them with a candle helps the bullet drop out.

I use Rapine Mold Lube. It's a black paint like substance I purchased about twenty years ago. I have a crafter's paint brush and I paint the entire inside of the mold. Then I smoke it with a candle real good.

As for the lead I heat it real hot. I want it to be hot and shine. To test the temperature I dip the corner of the mold in for the count of ten real slow. Lift the mold up and it lead should not stick to it, or you can light tap it and make it call back.

Then I put a chunk of candle wax in the molten lead and light it. After the flame burns off, I have a tin scraper that I pull all the sludge to the side and lift it out.

I also use a ladle to get my lead out.

ok just finished, stopped when I used up half my 10lb pot. when I got perfect bullets, took the temp, 750degrees at setting 8 about an inch down my pot. I used an hot plate to warm the mold then dipped the corner in the lead for 30seconds.

I use to use really hot soapy water. the last 4 molds I got in, I tried tooth paste and an tooth brush. really happy with the results. no mold release in the cavity not even smoking.

little kroil or paraffin on the screw, may get in the cavities so i do it as close to the start as the session.

btw, I have really gotten away from taking temps when I cast.

fluxing with an wood dowel rod, just stirring the lead. use my lee ladle to skim the impurities, I have an spout ladle I use to cast with. i figure it can hold 1 to 2lbs of lead.

As a caster we all learn different techniques that work for us. There are no bad ones if you are getting good boolitz.

I bottom pour all, even 950 grain 50 BMG boolitz.

I use a 10 lb. 30 yr old LEE BP pot. I keep the spout clean by using my clean ingots.

All LEE pots require different setting on the dial to hold the correct temp for that alloy and mold. No two are the same. The thermostate on LEE pots is just reading the radiant heat from the pot threw to the tower that houses the Thermostat. If some have a fan blowing near there cast setup it, will require a much higher setting to reach the optimum melt temp for that alloy and mold.

Every mold is it's own character and requires different handling. For My Hard cast I use a WW alloy and usually water drop. But everything under 30 call I heat treat in the oven for hard Cast, if that is what I want.

Bullet size as dropped from the mold can be controlled some, to a point, that being the actual cavity size/ and material the mold is made from. A alloy of pure lead will drop the smallest boolits, the more tin, antimony, arsinic, and other impurities will cause/allow the boolit to cast larger. Good quality lino type will cast the largest boolits of most readily used alloys. Mold temp is also a factor here!!! The hotter a mold gets the larger it will cast, Thermo expansion. if I am water dropping frosted boolits they will average .001+ larger that a cooler mold that is dropping shiny boolits as Corey has displayed.

I use Bullplate to lube my molds, I do treat some cavities with Rapine Mold Prep as mentioned by Cayugad. Bullplate allows for the sprue to be cut while still is a semi fluid state for max temp when water dropping, love the stuff. {A google search will explain what Bullshop Bullplate is. }

Just my 14 cents.