Lyman M- Die

[hornady]

In the past I have used the Lee universal expander Die for loading cast Rifle bullets, but was thinking of switching to the Lyman M- Dies, any opinions would be helpful. Thanks

[btroj]

I use M dies a lot for rifle. I like the fact they can be adjusted to just barely open the case mouth so the bullet will seat easily.

Brad

[Char-Gar]

I have always favored the M die type of neck expansion. The die does not bell the case mouth, but expands it for a short distance. It helps in seating the bullets straight.

[hornady]

Thanks guy’s I am only punching paper, but loading three 30 cals, from what I have read I can get by with 2 dies, one for the 3030 and one for the 308 and 3006. My mold is a Lyman 170 Gr, GC bullet. .309 works well for two of the rifles and the 3030 likes the .310 a little better. from what i have read the 3030 takes a shorter Die,

[atr]

I agree with Brad (btroj)....

and M dies have improved the accuracy of my cast loads
also, my .308 Win M-die does work for my 30-30 cases as well
atr

[C.F.Plinker]

Lyman recommends the long body for the .308 and 30-06. The trim-to lengths are 2.005 and 2.484 inches respectively. They recomend the short body for the 30-30 which has a trim-to length of 2.028 inches. You should be able to use the long body for all 3 calibers you are loading for.
The 30R expander plug has the first step at .307 and the second at .311 inches where as the 31R has the steps at .310 and .314 inches. The 30R plug should work for both of your boolits.

[selmerfan]

I'll add to C.F. - you CAN use the long body die for .308 and .30-30, I do it right now.

[462]

I use an M die for all handgun and rifle cartridges. It is far superior to the universal "flaring" die.

One long body and three different expander plugs take care of my .30-30, .30-'06, .303 Brit., 6.5X55 Swede and 7.5X55 Swiss cases.

[smoked turkey]

If you don't already have the 'M' die you would be better off to purchase the short body and it will work for both long and short cases. The long die can be used for short cases but it is sometimes just barely, while the short body die can work without a hitch.

[riorider]

Smoked turkey hit the nail on the head with the short body doing both and they are better than a universal flaring tool!

[Casting Timmy]

I'd agree with just buying a short M die as you could use it for the long and short cases.

[dromia]

I have always favored the M die type of neck expansion. The die does not bell the case mouth, but expands it for a short distance. It helps in seating the bullets straight.

I concur, "M" or step dies are far superior to tapered flare dies for cast boolits.

[MattOrgan]

M dies are great things work for the other kind of bullets too. The "short" body is a plus for various cases say 7.62 x 39mm through .300 H&H. Another benefit if you have a lathe or a friend that does is you can make specific sized expanders fairly easily. I had to do this back when Ruger introduced the M77 in. 416 Rigby. RCBS came out with their beautiful. 416 mold and Hornady immediately came out with gas checks. Lyman had no M die so I made an expander for the. 416. Made several others since. Great product. Sorry for getting stuck on blab.

[Baron von Trollwhack]

The best reason for using a "M" die is for CONSISTENCY of bullet pull.

You would not try for the most accurate loads for your efforts without attempting to be consistent in the many operations of producing accurate reloads.

You can actually feel the neck tension when placing the insert into the case neck and removing the insert. This is why neck annealing is also important regarding case neck uniformity. And case length ( the die works on the neck, right). And crimp, if used, and kind of crimp. It is why boolits are sized consistently, and carefully.

BvT

[Three44s]

Though I am a big supporter of Lyman "M" dies I find that the universal expander from Lee and or the expander sent with the three dies sets for handguns often are useful for a team expanding line up.

I use a Lee Classic turret press for a lot of my metalic work and will when necessary set up more than one expander and adjust accordingly for a staged expansion of the case mouth.

Three 44s

[hornady]

Thanks guys, I put the order in for the M-die. But Mid south has it on back order, the arrival date came and went, they have moved the arrival date twice on me now.
Mid south is pretty good though.
Must be a good die seems everyone is ordering it, I checked a couple other places, same thing on Back order

[462]

..."I checked a couple other places, same thing on Back order"

Midway?

[1hole]

"thinking of switching to the Lyman M- Dies, any opinions"

The M is the best expanding/flaring design on the market. It's so good Redding copied it, at least in pistol dies.

The expander section has a normal diameter plug but with a short section a little larger than normal bullet diameter, plus a flaring step if you need to do that; adjusted correctly the flare portion will rarely be used. You will be able to set a bullet into the short oversized section without it falling over and that allows seating to be straighter and with no damage to the bullet heel, meaning it will work very well for both cast and jacketed bullets.

I got my short .30 cal M in a set of Lyman .30 carbine dies, it has a very wide range of adjustment and works fine for everything else. I like it so well I've gotten others for all of my calibers and removed all the standard decapping/expanding assemblies. I do all of my decapping with a Lee Universal Decapper and all expanding with the M, that has reduced my average seated bullet run-out measurably.

[hornetguy]

M dies are great things work for the other kind of bullets too. The "short" body is a plus for various cases say 7.62 x 39mm through .300 H&H. Another benefit if you have a lathe or a friend that does is you can make specific sized expanders fairly easily. I had to do this back when Ruger introduced the M77 in. 416 Rigby. RCBS came out with their beautiful. 416 mold and Hornady immediately came out with gas checks. Lyman had no M die so I made an expander for the. 416. Made several others since. Great product. Sorry for getting stuck on blab.

This is correct. I have one die body, and have made several different expander plugs. I turned my own threads on mine, just for the experience, but if you buy a length of 9/16 X 18 threaded rod, you can just turn it down for whatever expander diameter you want.

[Hank10]

Got my 1st M dies in 1966, now have dies for over 150 calibers and have M dies for all of them. Use a smaller expander on your decapping die or grind it down so it doesn't touch the case. Use them for jacketed as well as cast. I mike both diameters of the M die and engrave it on top of the die stem like .307/311. They're not all created equal.
H10

[Clouseau]

Would this die type achieve the desired effect for seating CBs, or are the mandrels insufficiently oversize compared to nominal bullet diameter?

http://www.sinclairintl.com/.aspx/pid=38807/Product/Sinclair_Generation_II_Expander_Dies
http://www.sinclairintl.com/.aspx/pid=33134/Product/Sinclair_Expander_Mandrel___oversized

[stubshaft]

The expander die. The oversized mandrel is for neck turning cases, NOT for expanding necks for boolits.

[462]

It won't install the "step", which is what makes the M-die so unique and work so well.

[Clouseau]

The motivation for my earlier question was that I contemplated finding some platform with a fine-grained expander mandrel selection, sort of like pin gages, but it appears Sinclair only has a few sizes anyway. Was considering using those for the primary expansion, and then a Lee universal expander for the flare. Never mind that idea then.

I have a Lyman M .30 short and .31 long on order, with the thought that these two bodies and additional mandrels should cover the spectrum pretty well.

Have been pulling my hair out to come up with an approach to neck sizing directly for the larger CB diameters, for 6.5x55, 7.5x55, 54R, and 8mm Mauser. It looks like Lee collet necker availability is overall better than Redding S type, for these, and then there's the matter of cost, so I'm planning to go with Lee collets and custom mandrels, and quite possibly Redding body dies where available.

- 6.5x55 has a designated Lee collet necker. Just need custom mandrels.
- 7.5x55 is in the same boat.
- 54R has no coller necker love, but folks have pointed out that the 7.5x55 die body and collet, with a mandrel and collet cap from the .303, is a good start for 54R. Planning to go with this, since I already have that die.
- 8mm has a designated Lee collet necker. Once again, custom mandrels as needed, it would appear.

This is all in preparation to load my first ever CB rounds. Been building up a stock of CBs; the sizer is all ready to go; just need to get the neck issue figured out (with the M dies for now, I figure, while waiting on the custom mandrels) and all should be good to go.

[nanuk]

This is correct. I have one die body, and have made several different expander plugs. I turned my own threads on mine, just for the experience, but if you buy a length of 9/16 X 18 threaded rod, you can just turn it down for whatever expander diameter you want.

HG: can you also turn a long tapered expander form this rod and use it to upsize calibers using the M-die body to hold it?

such as .308 -> .338?

[44 WCF]

I too have used M dies for an eternity. You get these quirks in your brain and you have to keep doing what you've been doin, cause you always get what you got, when you do what you've always done. Oh, screw it, they work for me and I keep using what works for me,,,Just don't tell my brother in law Sharky,

[nanuk]

I just picked up an RCBS expander in .375, figureing I could reduce it to what I'll need for my 9.3.

but when I disassembled it, I found it is an expander plug, but with a flare at the top, NOT a step like the M-die.

the M-die appears to me to be the best design. I may have to see about getting expanders made to fit the RCBS... probably easier to reduce the AllThread and install in an M-die

[hornady]

The M die should be here today. I ordered it on 2/28/11. Checked the UPS tracking. Number.
I can start loading 30 cal, cast again, I sold the Lee expander, and then found out the Lyman M – Die was on back order every where.
I ordered mine from Mid-south shooters.
The weather in SWPA, has not been the best for shooting, but getting better. So by the time I get some loaded up, the range should be dry enough to get back to the bench.