Lyman M Dies

[Lucky Joe]

I have a quick question. Today I found in a gun shop a couple of M Die's, by Lyman. They are a .45 ACP and a .45 Colt, my question is do any of you use them and if so will they help me make better ammunition. Or would the Lee Crimp Die be a better way to go?

[454PB]

M dies are designed to put a flare and slight expansion on the mouth of the case and prevent shaving of the boolit while seating. Most all handgun cartridge die sets come with expanders that do this, but most rifle dies don't. The Lee FCD is for another purpose altogether, it applies a heavy crimp and also sizes the case (and in some cases the boolit) to factory load dimensions. So the short answer to your question is no.....M dies aren't needed for handgun ammo, and the Lee FC dies serve to resize loaded ammo and are not normally needed.

[Lucky Joe]

454,

After I posted this question I went to the Lyman site and studied the M dies. I realized my mistake. Thanks for you reply, my goal is to make my ammunition as good as I can. Lots to learn and this is a good place to do that. I'm going to leave this up and write it off as a humbling experience.

[Pepe Ray]

Lucky Joe
I Might be interested.
What sizes were marked on the die? How did they differentiate between the Colt and ACP? Perhaps the dealer marked it on a tag? What was the price? How tuff is it to re-examin them? Is this enough questions?
Pepe Ray

[454PB]

454,

After I posted this question I went to the Lyman site and studied the M dies. I realized my mistake. Thanks for you reply, my goal is to make my ammunition as good as I can. Lots to learn and this is a good place to do that. I'm going to leave this up and write it off as a humbling experience.

There should be nothing humbling about it at all. There are many specialized tools available for handloading, and we can't all know what they are used for. We learn by asking!

[jonk]

M dies are quite useful for cast bullets, esp. without gas check. However they are caliber specific, so I use a Lee Universal flare die.

[1hole]

I agree with jonk that the best use of a Lyman M die is with cast bullets. I wouldn't load any lead bullets without that M die for my expander. It appears that Redding agrees, they now have a copy in their handgun die sets. That said, I feel almost as strongly about its use with jacketed flat-based rifle bullets.

The M expander's short second step above bullet diameter simply allows any bullet to enter the case smoothly, even without doing a mouth flare as such. Easy entry is a significant aid to straight bullet seating in jacketed bullet rifle cartridges.

[dromia]

Ditto what 1hole said, I find that the "step" the "M" die forms is far superior to just a case flair, a la Lee expander die for instance.

The positive step formed by the "M" die really helps the boolit seat straight in the case ensuring concentric rounds.

I have them for all my calibres and have different diameter plugs for the same calibre for different boolits and cases, these are easily made by anyone with lathe skills and access to a lathe.

[georgewxxx]

Always wondered what Federal, Winchester, and Remington use to seat in their factories.