Lyman M Expander Die - Thoughts?

I've always loaded on Dillon equipment, & for the most part, use their dies - at least for pistol / revolver calibers.

Recently, one of my CB suppliers recommended the Lyman M expander die, for expanding. He says the "slip fit" afforded by the Lyman die, is superior to the more common "belling" expander used by Dillon.

I'm on the fence, but this guy makes a great bullet - & isn't trying to sell me dies. Wondering if it might not be worth the $20+/- to give one a try for .45acp, 200LSWC's.

Any thoughts? Thanks in advance!

I, for one, have been using the "M" expanding dies for 35 years. They are superior to conventional expanding dies when working with cast bullets. When loading jacketed bullet, I haven't found a whole lot of difference between the "M" die and a conventional expander.

Bruce

The Lyman M die (and now the Redding expander since the Lyman patent has run out) offers a unique case prep not provided by others. It provides better bullet alignment than normal belling can provide. In my view it is worth the expense and extra step for the benefits. Provided courtesy of Unclenick is this picture that show how the M die works.

I had a similar question and ran across this thread when doing a Google search. This morning I was advised to use the Lyman M type expander die by the owner of a cast bullet company. I was placing a bullet order and he asked me about my expander die. He was quite adamant and that I should not use my present Hornady expander die, which flares the case mouth, with his cast bullets.

I use the Hornady LNL progressive press for reloading a variety of pistol cartridges. I use Hornady Custom Grade New Dimension 3 die sets for all pistol calibers that I load (.380, 9mm, .40 cal, 38 Special, .357 magnum, .45acp) along with the Hornady powder measure. I also use a Hornady powder cop.

I have several questions. 1. Should I substitute a Lyman M type expander die for the currently used Hornady expander die? 2. If I do switch to a Lyman M type expander die, do I also need to change the crimp die? My present Hornady crimp die, that came in the set, is a roll crimp die. Will this roll crimp die work well with a Lyman M type expander die or will I have to change to a Hornady taper crimp die? I thank all responders in advance.

The m-die will work with any die set, I use a m-die with Hornady, RCBS, Lee & Lyman die sets.

The m-die will keep the reloader from swaging the lead bullets from using the wrong expander die (too small) or shaving lead off of the lead/cast bullets from starting the bullets cockeyed or again too small of a bevel/expansion of the case.

A standard expander die (one that actually enters the case and expands the case ID where the bullet will be seated) does, in general, an excellent job. The "standard" Dillon "powder funnel" that ONLY flares/bells the case mouth is useless unless you are shooting jacketed (not plated) bullets. The cartridge-specific Dillon "powder funnels" are excellent.
However, the problem with lead and thin-plated bullets is that they can easily be swaged down in diameter or forced of center by the seating stem if the case hasn't been properly expanded.
The case ID, where the bullet will be seated, needs to be 0.001-0.002" smaller than bullet diameter. Most expander dies are made to size the case 0.003-0.004" smaller than the nominal bullet diameter (i.e., 0.352" case ID for a 0.355" bullet) which is fine for jacketed but is way undersized for lead.
The advantage to the Lyman M-die, not shown in the drawing, is that it has three functions: 1) expand the case ID for tight bullet fit without being too small (you can order the expander plug in different sizes to get the specific size you need or have them make a custom one), 2) exapnd the case to bullet diameter or slightly larger so bullet can seat firmly and straight in the case, and 3) flare/bell the case mouth.
For the Hornady, you can order the PTX (powder-through expander) insert for lead bullets. This takes care of two of the Lyman functions (where the bullet seating "cradled" is nice but not a need for pistols being shot at less then 100 yards) and allows the continued use of the Hornady powder measure as a powder-through operation. I had a L-N-L AP and found the PTXs were more that good enough and never felt a need for an M-die.
If you are seating lead bullets and, if after seating and pulling the bullet, it is not swaged down and it hasn't raised a bulge on the side of the case where the case walls are thinnest, you don't need an M-die.
Personally, for the L-N-L, all I shoot (except lately in 9mm) are case or swaged lead bullets and found the Hornady more than adequate. Die set-up, IMO, should be:
1) Size/decap
1.5) Prime
2) Powder-through expansion and charge (thus, NOT using the expander die in the die set)
3) RCBS Lock-Out die
4) Look in case and see the powder and then seat the bullet
5) Crimp
When I got a couple of Dillon 1050s, I then found a "need" for an M-die--until I got the cartridge-specific "powder funnels."
So, answer your question: No, you don't NEED an M-die, but they are nice to have.

I keep thinking of trying one of these since I load cast in most of my loads. I have the Powderfunnels.com PTX insert in my LNL AP's powder measure and using flat base .45 ACP bullets they insert just fine. For my cast loads in .30-30 I flare the case mouth with a Lee universal case expander die and once again they feed in just right and the Lee FCD closes the mouth back again with the right amount of crimp. No shaved lead, no off center bullets, no problems loading or shooting what so ever. I don't doubt the M dies work (or the new Redding offering) but I'm not sure they are as needed as some think they are.

smlake said:

I have several questions. 1. Should I substitute a Lyman M type expander die for the currently used Hornady expander die? 2. If I do switch to a Lyman M type expander die, do I also need to change the crimp die? My present Hornady crimp die, that came in the set, is a roll crimp die. Will this roll crimp die work well with a Lyman M type expander die or will I have to change to a Hornady taper crimp die? I thank all responders in advance.

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1. At this point, I'd have to concur w/ NOYLJ, QUOTE: If you are seating lead bullets and, if after seating and pulling the bullet, it is not swaged down and it hasn't raised a bulge on the side of the case where the case walls are thinnest, you don't need an M-die.

2. In theory, the seater should iron out just about all belling - from any type of expander. At that point the question is, are we loading for revolver w/ crimp groove bullets (roll crimp), or auto w/ no crimp groove on bullet (taper crimp).

At least that's my take on it...

noylj said:

The "standard" Dillon "powder funnel" that ONLY flares/bells the case mouth is useless unless you are shooting jacketed (not plated) bullets. The cartridge-specific Dillon "powder funnels" are excellent.

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Thanks for the well thought out input. Got to tell ya' though, I'm now a bit confused. Are you saying that there actually IS a standard / non-caliber specific Dillon powder funnel? I thought they were all caliber specific.

That said, I've never actually measured the expanded ID. Now I'm going to have to...

For the record, I've been able to control the dreaded off center bullet bulge, by:
1. adjusting the dies w/ a centering piece of brass - or loaded round where appropriate, &
2. backing the sizer off bottom (partial FL sizing) a bit as needed - maybe 1/4 - 1/3 turn.

Seems to work, & as far as I can tell, neck tension is OK. Pulled bullets still measure .452", & it usually takes 3 pretty good whacks, to remove a seated / crimped 200LSWC.

Loaded & moon clipped rounds now chamber easily in a 625-3, & no bullet "push in" is noted after repeated chambering in an auto .

Dillon sizers seem to actually (in some cases anyway) size brass down a bit further the necessary. Heard them referred to once, as "coke bottle sizers"...

Still, have to admit to being curious about the m die. I'm all about accurracy, & if it helped at all, it might be worth the extra step.

I am a big fan of Lyman's M- Dies and have them for all of my larger magnum cartridges and most of my straight wall rifle and black powder cases too. Unlike the conventional expander plugs with a funnel like taper the M die is a straight forward two stage approach that is just must easier on the brass and about impossible to screw up.

With the old style expander plugs as shown in the attached photo it is pretty easy to have your die shift due to a loose ring or whatever and I mean just a hair too deep and you bell the mouth of your cases to the extreme. This will certainly shorten the life of your brass after a while so it is wise to expand just enough and not much more. The M die will keep this from happening since the lower portion of the plug is about .004 - .005" under and the step is at bullet base diameter. Easy to set and easy to feel with no risk of blowing your brass out. With the plug body being consistent in diameter the die is faster to set up and reduces most of the problems associated with the occasional long case if you don't trim or segregate your brass.

As I recall Lyman used to offer these in special sizes for those special odd sized bullets and since bullet moulds is a big part of their business it was very helpful. Not sure if this is still true but you can size these plugs yourself.

Top plug is an M Die. The bottom is RCBS



regards

garbler said:

I am a big fan of Lyman's M- Dies and have them for all of my larger magnum cartridges and most of my straight wall rifle and black powder cases too.

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Thanks for the pic, & additional comments. I am wondering if any of these dies, are suitable for multiple calibers. Assume 38 / 357, but 45acp / 45 colt would be... handy.

Speaking of handy, a powder through design for progressives - would be just that.

The M die works pretty well, especially with lead bullets as was noted. As most of my sets are Redding, their expander which was also noted as being M type, is very good. I dont load a lot of lead except in 38, so I do use them in that application.

The Lyman die has a somewhat less finish to it if that matters to you vs the Redding. It works well though.

I found I had to put a bit of oil, or the Collector oil on the Lyman when putting it away in our more humid and damp conditions in Texas. Just to keep and surface rust away. I also have used the Tipton rust chips in the die box successfully.

If you are using the M die, keep an eye on the thead of the plug as some of them can loosen up.

One other thing I remembered is that on my M's I had to work with the stem tightness settings some.

If I cinched it down too much the plug might not center up as well, so I had to leave it where it would wiggle or float just a bit to center up on some cases.

When I carefully rotated the stem looking at the plug end then I could see some offset in the rotation, and then some part where it was minimal. When aligned in that position and left just a teenie bit of stem float, then the whole process ginned along.

Hope that helps.

Can a Lyman "M' type expander die work with a Hornady combined bullet seater and roll crimp die? I use the Hornady New dimension dies sets (.380. 9mm, .38spl, .357 mag, .40 cal, .45 acp) with my Hornady LNL AP progressive loader. Or perhaps, should I get the Hornady PTX universal Powder Through Expander instead of the Lyman "M" expander dies for these calibers? Midway does not list the PTX in their present catalog but others probably carry it. Other posts indicate the Hornady PTX expander can be difficult to adjust.

smlake said:

Can a Lyman "M' type expander die work with a Hornady combined bullet seater and roll crimp die? I use the Hornady New dimension dies sets (.380. 9mm, .38spl, .357 mag, .40 cal, .45 acp) with my Hornady LNL AP progressive loader. Or perhaps, should I get the Hornady PTX universal Powder Through Expander instead of the Lyman "M" expander dies for these calibers? Midway does not list the PTX in their present catalog but others probably carry it. Other posts indicate the Hornady PTX expander can be difficult to adjust.

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I don't know anything about your press but it should be fine. The M die expander plug does one thing only and that is straighten out the case mouth and expand just enough for the bullet to enter and seat. The seating die with either roll or taper crimp takes it from there. They work in sequence and it really makes no difference who makes what. I have many sets with maybe a RCBS size die and maybe a Redding or Bonanza seater die. I mix and match all the time no problems.

Regards

Maximumbob54 said:

I keep thinking of trying one of these since I load cast in most of my loads. I have the Powderfunnels.com PTX insert in my LNL AP's powder measure and using flat base .45 ACP bullets they insert just fine. For my cast loads in .30-30 I flare the case mouth with a Lee universal case expander die and once again they feed in just right and the Lee FCD closes the mouth back again with the right amount of crimp. No shaved lead, no off center bullets, no problems loading or shooting what so ever. I don't doubt the M dies work (or the new Redding offering) but I'm not sure they are as needed as some think they are.

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Bob, how do you like the insert?

I have the Lee powder through die and from what I understand the H-LNL has it's own so I won't be using the Lee on that press but I did notice in the video the H-LNL has the standard insert like the Lee.

I have done well w/the Lee and its standard insert, so is it worth it ?

Thanks,
Jim

Rollbar said:

Bob, how do you like the insert?

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I love it. It's outfreakingstanding. I cannot stress enough that Hornady needs to pay that guy a bunch of money and just sell them with the press. I bought the Hornady bullet feeder to get the .45 ACP insert and the Powderfunnels.com insert works better than the company caliber specific version.

Rollbar said:

I have the Lee powder through die and from what I understand the H-LNL has it's own so I won't be using the Lee on that press but I did notice in the video the H-LNL has the standard insert like the Lee.

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The only press I like the Pro Auto Disk on is the Classic turret because as the turret rotates it makes sure the cavity in the disk gets filled very evenly each time so the powder drop is ver consistant. Any other way I've tried to use it I didn't care for it. But when used with the Classic Turret I think it's great.

Rollbar said:

I have done well w/the Lee and its standard insert, so is it worth it ?

Thanks,
Jim

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If you buy it and don't like it I challenge you to go back and make sure you adjusted it right because I do not see how someone couldn't like that insert.

I've heard they will come loose and if you're not paying attention you'll start ruining brass. I used some red lock-tite on mine and haven't had a problem. Works great. I'm pleasant surprised with my Lyman die set. Couldn't find the Hornady one I wanted and settled, don't regret it at all.

I've said it before but--
the powder funnels.com and the Lee Universal expander DOES NOT expand the case--they ONLY flare/bell the case mouth. This can work fine with jacketed and MAY work well with plated, but you are quite likely to swage lead bullets down in diameter and/or force the bullet off center and cause a case bulge where the case walls are thinnest.
If you have five stations or more, you can expand the case first and then flare/bell the case mouse at the powder measure, but the caliber specific Dillon powder funnels, the Lee PTE dies, and the Hornady PTXs for the both jobs excellently. I have never had a problem with any of them.
I have, however, had problems with old brass that "springs back" when expanded and found I either need to buy a custom expander or use two expander in sequence to actually get the case ID where it needs to be for lead bullets.
If you have bad accuracy or leading with lead bullets, you might want to consider going back and actually expanding the ID to proper dimension for bullet seating (try to measure the case ID before bullet seating--it should be 0.002-0.001" smaller than bullet diameter for best results).