ideal and cardboard boxed Lymans vs plastic boxed Lymans

[farmbif]

I have a few Lyman molds some old and some newer. some time after they changed to the orange plastic box the quality seemed to go down and there were problems with molds dropping undersized bullets. all of the older ideal and cardboard boxed molds seem to drop bullets that are right on the right size or even a bit oversize. like my old 358156 ideal mold that I lube size at .360, its great. I use the same clip on wheel weight alloy with a bit of tin added for everything in center fire cartridges.
is it safe to assume that this is how it is and the older molds had better quality control

[.22-10-45]

I believe the early Ideals were purposely made oversize to overcome the tolerance issues in firearm bore sizes. Then too, in those days, sizing was thought to improve a bullet. An oversize cherry ( mould cavity cutting tool), will allow a longer cutter life as cutter dia. is reduced when re-sharpening. I have noticed the nice curves and radius of the earlier Ideals and Lyman are now replaced with angular shapes..probably due to CNC and bottom line economics. Perhaps as the older cherries became worn undersize, there just were no more of the old school cutter grinders left to create new ones so they just kept using the old ones. There is no excuse for undersize cherries with modern methods. Others here have mentioned that improper alloy is the reason for them dropping undersize.
On a side note, Bill Loos told of a former worker at Lyman during the late 1970''s who saw scrap gon's overflowing with discarded mould cherries...what a waste.

[Larry Gibson]

The cherries for Ideal moulds for bullets that are used in smokeless powder cartridges were originally designed and made to cut cavities for Lyman #1 alloy. That alloy was a quadra alloy containing lead, antimony, tin and copper. #1 alloy drops a smaller diameter bullet because the alloy shrinks more when it solidifies. When Lyman bought out Ideal they continued to use many of the already made cherries. Lyman then standardized on Lyman #2 alloy back in the '70s and all newer cherries were made to cut cavities that drop bullets at the nominal diameter of the particular bullet. That nominal diameter is the first three numbers of the mould designation such as in 457xxx.

Thus, expecting a Lyman mould to drop a larger bullet with a softer alloy, such as COWWs, which shrinks more on solidification is an unrealistic expectation. That expectation is what has led to the complaints and myth that newer Lyman moulds drop undersize bullets. As mentioned, cherries are made initially slightly over sized so they can be sharped several times to get numerous cavities cut. That gives a +/- to what varied moulds will drop the same bullet diameter at. About 15 years back i offered to test any "new" Lyman mould that was claimed to cast undersized bullets. If the mould would not cast to the nominal diameter with #2 I would buy the mould for what the owner paid. I tested 20+ moulds sent to me by forum members and did not have to buy a single one as all cast to nominal or slightly larger diameter.