I got that 125 mold in with the pins, and ran it today with the hollow point pin. I had thrown into the pot along with my normal stuff some cast bullets of unknown vintage a friend gave me. Some lead free solder, and my wheelweights. Took quite a while to stop getting wrinkles. But. it is a four hole mold, and with no consistancy to one hole, the base of the bullet up on top was not filling out regularly on them.
I would pour, couple would be fine, and for some reason would not get a consistent fill on the top. Couldn't figure it out.
Should be nice and flat after the sprue cutter cut it, not so, and a little in some parts were not completely filled out.
Not sure what was causing that. Only thing i could think of i might have gotten a little of that oil he provides in there...
they cast by the way mostly to 126grains, and .358 to .359.
poor base fillout is generally caused by inadequate venting, in my experience. First thing to try is loosening the sprue plate; I don't like casting with a floppy sprue plate but sometimes that's what it takes until you vent the mold better.
Another thing I do to all my molds is stone a small 45 degree bevel on the top of the block faces where they contact each other under the sprue plate. This acts as a vent to help base fill. Don't overdo it, a bevel about the thickness of your thumbnail is good, maybe a little more. Use an oiled stone, not a file.
Also, some people swear against it (I don't know why) but smoking your mold with a butane lighter does help fill out, especially with hollow point molds. Most of what I cast any more is hollow points, and I'd like to think I have it down pretty well; if I'm not getting good bullets by the second cast, something is wrong. The first remedies I always turn to are venting and smoking. Do not smoke a mold with matches, wood, candles, or anything else containing wax or oil, only use clean gas from a cigarette lighter.