Lee 2 Cavity - Slanted/Uneven Bullet Bases?

I am fairly familiar with Lee molds. Most of mine are the 6 bangers. I own a few dual cavities, but most are roundball molds and see light use. I recently picked up a Bulgarian Makarov (fun little pistol!) and needed 95 gr pills. No 6 cavities to be found, so I went with the only option. Everything ran well for probably 500 or so casts. I noticed what appeared to be a ridge on the right side of the bullets after the spru was knocked off. I started paying attention, and just about every cast looked this way. It starts almost halfway across the bases, and probably is probably .040 higher than the rest of the base. Forget about accuracy! All the pins and screw appear tight. What is going on?

It sounds like the mold blocks are misaligned. Check for manufacturing defects, then check to insure that the pins are protruding the same amount.

I would make sure the bolt is snug on the handles then carefully check the alignment holes and pins for a bit of lead or contamination.
I assume you lubricated the pins after the first cast (had to ask but don't need an answer)

Things don't quit working for no reason. I would place money on the pins

Its more likely than not that the alignment pins have pushed back and or fallen out.This is not uncommon with lee moulds,and catches you by surprise.After a bit/lot of use the beeswax you dob onto the pins will glue them in.My favorite lee has had the pins fall out numerous times,but the moment you see the fin on the cast you know what it is and correct.Dont lose the pins,which i did first up.

If you can't fix it send it to Lee, enclose a note saying you bought it less than a year ago. They'll send you a new one and you're only out the postage.

Lee tells you to lube the pins with bullet lube,this sticks the pins in place .hopefully.Oil does not leave a residue to seal the pins.If you get a new mold from lee,youll likely have the same issues if its not lubed like they say.Beeswax leaves lots of hard residue,and seals the pins in place.Lee molds are good value for money.....they are not foolproof.