new to me mold 429421

[1bluehorse]

Picked up a used Ideal/Lyman 429421 DC the other day for 40 bucks (round lube groove)...it's pretty well used for sure, had to clean up screws and holes with a tap and die set but the cavities seemed pretty good, however it wouldn't drop bullets for spit...however I did cast a few bullets and with some very fine compound ran a few of them in the cavitys with a drill...they drop much better now..have to run the sprue plate very loose otherwise I get quite a bit of flash on the base of the far bullet (any ideas there for a fix?)...good news, (and maybe bad depending on what one wants) one cavity drops (first cast using WW) 258+ to 259+gr and miced at .432+ and the other drops about 2gr lighter and miced at .4315ish... (I mic'ed over the lube groove to hit both the base and first drive band as the very bottom of the bullets were a bit suspect to me....) weights were from a low of 256.6/257.8 to a high of 258.5/259.8, with a obvious line between the two cavitys..I think I'm happy with that...I need to get a .431 sizer though....opinions? ideas to make it better or leave it alone..

[leadman]

I have had the same thing with some of the Lyman molds. Either the top of the block is worn or the sprue plate is bent. The original thin sprue plate did bent very easily. Lyman makes a mold rebuild kit that has a thicker sprue plate and all the hardware parts.
I adjust the sprue plate pivot screw while looking at the side of the mold so I make sure it is laying flat on the top of the mold.

[Shuz]

Tighten the sprue plate, and/or reduce the lead pressure into the mould, assuming you are using a bottom drop furnace, and your issues may disappear. Size your boolits to .431 with a good lube like WFFL or Lars carnuba red, you should be "good to go".

[1bluehorse]

What I've found with this mold (it must have been used a bit) was the corner of the mold where the sprue plate screws in, has been "rounded" down a bit, I assume from wear...not sure what can be done with that...or if it will be necessary, as long as I can get good bases on the bullets the sprue plate being a bit loose shouldn't be a problem, other than it's a bit annoying.....and I just ordered a .431 sizer die...