Is the Lyman M Die a usefull tool for CB?

[257 Shooter]

I have been looking at the Lyman "M" die for expanding case mouths for cast bullets. What is your experince using this die vs the expander ball in your deprime die?

Thanks,

Jim

[9.3X62AL]

I think the Lyman M-die is one of the BEST upgrades a cast boolit shooter can make to his/her reloading effort. Many, perhaps MOST modern die set dimensions sort of "assume" jacketed bullet usage, and the M-die's 2-step expander gives a MUCH better "start" into a case mouth than does a simple flare alone.

[Dframe]

I agree completely with 9.3. the M die is great for use with cast bullets

[GP100man]

seat a booilt then pull it & measure the differences between the 2 ???
i found my 357 brass was (down sizing ) mine & moved to a m die after charging with a lee powder thru die & auto disc measure , funny how that leading in the forcing cone & first 1" of barrel stopped.
the softer the alloy the more you need one & for rifle fo sho!!

WELCOME TO THE :cbpour: FORUM!!!!

GP100man:castmine:

[carpetman]

You'll get posts that the mouth can be flared with a Leatherman, using the grill from a 1952 DeSoto and driving into the case, screwdriver and whatever else you can imagine. The Lyman M is consistent and gets it done.

[STP22]

I can`t remember a time when I did not use the M-die. Standard dies size down too much to begin with...then the expander ball stretches the neck back to an inside diameter for condom bullets. In fact, the manufactuers have to dimension their FL dies for the thinnest brass that`s available to us. So the thicker brass gets quite the "workout" being squeezed down way too much, only to be opened up by the expander ball that does not meet our needs in the first place.

This would explain why some shooters experience split necks much sooner than others. There`s a bit of work hardening going on with the standard FL dies.

If you can reseat a cast boolit in a fired case w/o sizing and have adequate neck tension, you can skip the sizing die altogether. All you need to do is de-cap the fired primer and load`er up again.

[462]

257 Shooter,

Recently bought sets of Lyman dies in .38/.357 and .44 Spl/Mag. just to get their M die, and prefer it to Lee's flaring die. With Lee's flaring die, I was finding that the boolit was being down-sized when seated, like GP100man was experiencing. The M die eliminates that from happening.

I neck-size rifle cases so I use Lee's Universal Neck Expander Die when loading them with boolits.

[mike in co]

THE tool for case opening for cast boolits...period

[1hole]

In '65, my first two die sets were Lyman in .30-06 and .357. The .357 M die worked so well I now have 10 of them and plan to get 3 more. I love to use them instead of conventional expander balls for everything. Not only do they make bullet seating, any type, easier but the necks are left straighter too.

It's always been a mystery to me how conventional expanders stay alive in the market! At least Redding had the good sense to copy them for their handgun dies when Lyman's patents expired.

[Guesser]

Bought my first set of dies in 1957, 32-20, and have been in love with the "M" die ever since. I have them for every caliber and then some.

[higgins]

I've been casting for pistols a long time, and only recently started casting for rifles. When you first start using a rifle M die, you may flare the case mouth too much, which will result in difficult chambering because the crimp die cannot smoothly close the excessive flare. There's no need to force the case mouth beyond the small second step that just barely expands the case mouth larger than what the rest of the neck has been expanded to. Because of small variations in case length, I have found it's better to expand by feel with my antique Lyman Spartan press, rather than trying to adjust the die to properly expand at the top of the stroke, but if you have a press with more leverage you wouldn't be able to feel it as well.

[Dale53]

AL says it all.

Dale53

[mike in co]

I've been casting for pistols a long time, and only recently started casting for rifles. When you first start using a rifle M die, you may flare the case mouth too much, which will result in difficult chambering because the crimp die cannot smoothly close the excessive flare. There's no need to force the case mouth beyond the small second step that just barely expands the case mouth larger than what the rest of the neck has been expanded to. Because of small variations in case length, I have found it's better to expand by feel with my antique Lyman Spartan press, rather than trying to adjust the die to properly expand at the top of the stroke, but if you have a press with more leverage you wouldn't be able to feel it as well.


a) yes you should be no where near the big flare section of this die.

b) there is a reason why one should trim cases to length....

mike in co

[257 Shooter]

Thanks Guys for all the great info! Placed an order for 'M" Dies this morning.

257 Shooter

[cabezaverde]

I use the Lyman multi-expander die a lot for pistols. I will have to check tonight, but I believe the expander configuration is the same as M-dies. I like being able to drop powder through it and expanding the neck at the same time.

For pistol, one of these is a lot less expensive then a bunch of M dies.

[dromia]

Thanks Guys for all the great info! Placed an order for 'M" Dies this morning.

257 Shooter


You are wise to do this. "M" dies are almost as essential to successful cast boolit shooting as a pot, alloy and moulds.

[cabezaverde]

15120
I use the Lyman multi-expander die a lot for pistols. I will have to check tonight, but I believe the expander configuration is the same as M-dies. I like being able to drop powder through it and expanding the neck at the same time.

For pistol, one of these is a lot less expensive then a bunch of M dies.

I got thinking about this, and went to my reloading room to check things out. The photo above shows a true .35 caliber long M die on the right. On the left is the .38 pistol spud from the multi expander die set.

Both expanders measure .356" in their major diameters with my cheap chinese micrometer, below the extra "ridge" that creates a shelf in the case.

To me, that proves that the multi expand die is the equivalent of a set of M dies in all the popular pistol calibers. Plus, you can charge cases through the top.

[257 Shooter]

Thanks Cabezaverde. That is great info. I will add that to my next Midway order.

[TonyT]

I have been looking at the Lyman "M" die for expanding case mouths for cast bullets. What is your experince using this die vs the expander ball in your deprime die?

Thanks,

Jim

I have used the Lyman M dies in 7 different calibers for more than 15 years. A great way to get a cast bullet started into the case.