Lee powder through expanders vs. Lyman M Die

[Michael J. Spangler]

How do you guys like one vs. the other? I’m currently using the lee for 45/70
I find the lee is very case length sensitive. I have to adjust it just right to get a touch of flare on the case mouth but if a case is a little long (new picked brass that made it in the mix and hasn’t been trimmed) it bumps against the inside of the die and put a wrinkle in the case.
Kind of annoying.
Are the Lyman M dies more forgiving? I know I’ve used them in other cartridges but never for the 45/70.
Thanks!

[jimb16]

With M dies, it creates a step. If you take it slow, you can feel the step being formed. That means that an extra long case can be stopped before it is damaged and a short case will be felt as not getting stepped so you can cull it more easily. I prefer the M dies.

[Rcmaveric]

Depends on what i am reloading. For 9mm, 380, and 357 I use the powder through dies. I think better insert would be nice, but my ammo is good enough. Those are my mass shot and mass produced ammos. I set my lee perfect powder measure inside the powdee through die and go to town.

For rifle, i use the Lee universal expander with the NOE inserts. Voila universal M dies on the cheap.

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[Michael J. Spangler]

Depends on what i am reloading. For 9mm, 380, and 357 I use the powder through dies. I think better insert would be nice, but my ammo is good enough. Those are my mass shot and mass produced ammos. I set my lee perfect powder measure inside the powdee through die and go to town.

For rifle, i use the Lee universal expander with the NOE inserts. Voila universal M dies on the cheap.

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I’m going to have to look into that. That could be my solution.
I’m just looking for a more gentle shoulder so if I go to far I just have a lot of flare that can be crimped out vs backing up a few steps and resizing the case over again.

[Rcmaveric]

I’m just looking for a more gentle shoulder so if I go to far I just have a lot of flare that can be crimped out vs backing up a few steps and resizing the case over again.

Properly setting up die helps. Take the ram in the full up position with a peice of brass in the shell holder.

Screw in your powder through die until it firmly contacts the brass.

Now, lower the ram a smidge and screw your die in about 1/4 or so at time until you can sit a bullet inside the bell. Just barely bell it enough. Now your good to go to lock the die down. Screw you lock nut in just a decent hand tight. The ram stop will be your limit so your not over belled.

One thing i notice is powder through dies give a shallow bell. While the M die and NOE inserts actuall expand the whole neck and slight bell the mouth. Thays why i wonder if its possible to upgrade the powder through dies.

Its kind of hard to over expand. Those plugs come in gradiants. Pick the one you need so you dont over expand.



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[sigep1764]

I bought the Lee Universal Expander die and ordered the proper NOE plug designed for cast boolits. I now have one die that with changing the plug will expand whatever cartridge case I want. This is just what works for me.

[Walks]

I have a LYMAN M- DIE for every cartridge I load lead bullets in. I find that small step on the expander makes all the difference between seating a bullet straight & getting it cock-eyed & ruining a case. The expander is separate from the expander rod. Make sure it stays tight.

[bedbugbilly]

On my pistol ammo -38s, 357, 380, 9mm, I use the Lee powder through die for expanding. For my rifle brass - 30-30 and 8 X 57 Mauser, I use the Lyman M Dies. Main difference between the two for me? I load my pistol cartridges on a Lee 4 hole turret press and even with range brass with different headstamps, the powder through die does a good job for me - andI never trim the brass to length - no reason to. On rifle brass . . . I load that on a single stage press in batches. That's where the trimming to uniform OaL comes in. I agree with the statement that you can "feel" the M die when it makes the "step" and I find it a very easy die to use once it is set up properly for the length of brass I'm loading.

[Wayne Smith]

Physically every expander will be somewhat case length sensitive - it is inevitable. Solution is to trim your cases first!

[Hick]

I definitely prefer the M die. I have both Lee powder through expanders and M dies. The Lee expander for my 38 Long Colt constantly destroys the cases because the tolerances allow the expander to get slightly out of alignment with the case, and then they catch on the case neck and crush it. The problem with the powder-through dies is that they have very little taper to make sure they enter the case instead of hanging up and crushing the lip of the case. Lee customer service has been very helpful, but it seems to be a design issue with certain sizes of expander. Because the M die is solid at the tip it doesn't do this.

[Wheelguns 1961]

If you are going to load cast, then the m-die definitely. For smaller jacketed bullets, the powder thru expander seems to work better. With larger cast, the m-die will give you a little room so that your boolit doesn’t get swaged down, thus deforming your base. You don’t have to worry about that with a harder j-bullet, and you will get better neck tension with the powder thru expander.