Lyman 429421 vs MP 432-256 vs MP H&G503

[alamogunr]

Because I recently acquired a .44 Special FA 97, I have been researching cast bullet loads. Almost all mention the Lyman 429421. The MP432-256 is mentioned separately as a modern replacement. I didn't remember having the MP mold and ordered the same mold directly from Miha. While waiting for it to arrive, I discovered the mold among some I had not used in awhile. When the latest mold arrived, It was identified as H&G503 Clone.

Is there any appreciable difference in the three bullets? From what I can see they are essentially the same with a slight difference in the lube groove in the Lyman 429421. It is full round.

I admit that trying to differentiate between similar molds, I don't trust my eyes.

If the MP molds are identical, I've got unintentional duplicate molds. I'm going to cast with all three and see if I can detect any difference in performance.

[HWooldridge]

You might give some thought to your uses before picking a particular design. I have owned a SAECO mold for almost 40 years that throws the old 250 gr Keith design and that one bullet is all I have ever used in all my 44 Specials...then I bought a CA Bulldog and discovered it really likes a 220 gr bullet that I typically use in my 44-40 - so I save 12% in lead cost. Any terminal energy differences between the two don't mean much for my uses.

With regard to your three designs, you can measure the meplat sizes and lube groove widths to derive some differences.

[JAC43]

Hi John,

To answer your question I think you have identical MP molds between the two, and your Lyman is close but not quite the same in dimensions. My 429421 seats about .010" deeper than the MP H&G #503, and the length outside the case on the Lyman is about .015" shorter. Of course the 429421 has changed throughout the years so its a fair bet your mold is different than mine. Good luck with your FA 97.

[Mal Paso]

The 432-256 is the #503 clone and the last version of the H&G 503. The forward drive band is longer than the 429421 and is just inside the throats of my Colt when chambered. The 429421 was designed for 44 Special, the #503 was the redesign for 44Mag not that there is a problem with the 429421 in 44Mag.

They both work fine in Special or Mag, I like the longer front band on the #503.