First time bottom pour pot owner here. Also kinda frustrated.
For the past 1.5 months I have tried dialing in the bullet quality of my RCBS pro melt 2. I dont think it's an issue with the pot, I think it's an issue with my "settings" for lack of a better term.
I'm casting a 73 grain 227 bullet with a 6 cavity brass mold. (I have tried 2 other 22cal molds, one brass one aluminum, all with the same problems)
When I bottom pour I get anywhere from 50-75% rejects. I'm pretty picky about my rejects. The most common rejects are based on the bearing band fillout (rounded in places or beveled) and little wrinkles in the lube groove nearest to where the mold closes. With a ladle pour I can get down to 10% rejects if I have my rhythm going really well.
My process so far for trying out new settings is to adjust my mold guide, flow rate, and/or temperature on the PM2 and then cast 100 bullets with the bottom pour pot then 100 with the ladle out of the top of my PM2. With 100 225 bullets, the level of lead in the pot doesn't change much, but I get a decent sample size. Then after 100 of ladle pour, I go back to the bottom pour for about 50 bullets to make sure I was getting the same results as when I began.
So it's the same alloy (cww+2%) and same temp for the two groups of 100 bullets. The alloy is super clean.
I've tried, casting fast, casting slow, Temps as low as 690, as high as 750. The mold guide about .650 inches from the spout down to 1
25 from the spout.
With a bottom pour, there is something about the way the lead is delivered to each cavity that are causing these issues. I'm at my wits end of what to do.
For the life of me I cannot find the sweet spot to get this bottom pour pot to cast consistent quality. I'd be fine with 25% rejects, in an ideal world 15% or less would be nice. The problem with my current results is that there is no time or effort saved when I have to recast a bunch more bullets.
I have read many archive posts on the subject of ladle pour vs bottom pour. But what I do not see is an explanation of the settings everyone is using to get excellent quality bullets from a bottom pour pot.
What are your secrets? How can I close the gap with my bottom pour quality to get it closer to a ladle pour.