M Die: Do I need to do this? Help please

[milprileb]

M1 Rifle cast bullet loading:

I may be doing this M die thing wrong. My bullets are .309. I got the 3006 M Die as that is the caliber I load for. Its the long body .30 M Die. Some things come to mind that make me suspect I am on the wrong frequency here:

a. I should get a .309 or 310 expander , not use the .308 one I have now in M Die.

b.I should not use the .308 expander button on my Full Lenght resizing die, pull it off when I am resizing. If M die conditions neck , let the M did work the neck. No use doing it in the FL sizing die and then doing it again in M Die. I am overworking the necks of by 3006 brass.

I sure could use some advice here on the above concerns.

[elk hunter]

Most sizing dies will size the thinnest case neck to hold the smallest diameter bullet for that caliber making the the case neck quite tight on a jacketed bullet. The expander button expands the neck back to approximately .004 under bullet size, that generally isn't the best situation for cast bullets. The M die will expand the case neck slightly to say .001 or .002 under bullet diameter and flare the case mouth so that the cast bullet isn't distorted while being seated. I use the M die after sizing for most of my cast bullet reloading, but not all, as the three die sets sometimes get the case mouth dimensions right. There are times when I don't size the cases after shooting cast bullets as it's not needed. I simply reprime, dump in the proper powder charge and seat the bullet in the case, generally by hand.

This is a very general description of what happens, or at least how I do it. Hope it helps.

[Doc Highwall]

For my 308 Win I size the bullets .310" and my expander is .309".

You only want .001" - .002" MAX press fit of the bullet into the case neck. More then .002" not only distorts the bullets but also makes the loaded rounds have more run out.

Some of the black powder shooters do not even size their cases and the can even seat the bullets by hand but you need some start pressure with smokeless powder.

Loads for the range can have light seating neck tension as long as the bullet is seated into the rifling to raise start pressure.

[beagle]

Since I use M dies for everything as all I shoot is cast, I have eliminated the expander buttons on the FL dies and just use a decapping rod with no expansion. Then, the M die with just enough expansion to start the bullet base and it has worked for me for years with no need to worry about lubing case necks and getting stuck expanders in my cases. Seems to work pretty well for me./beagle

[Ben]

I use a .309 expander in my Lyman M - Die. I shoot .310 dia. cast bullets.
Do you think this combination offers hope ? ?

http://img.photobucket.com/albums/v494/haysb/019-6.jpg

[462]

Keep in mind that Lyman's M-die expander plugs are made to accommodate jacketed bullets, and are generally too small for cast boolit applications. For the .30-'06, I use the 31R plug.

I use a Lee collet neck-sizing die to deprime and "gently" (you must ignore the instructions) squeeze the neck.

[geargnasher]

M1 Rifle cast bullet loading:

I may be doing this M die thing wrong. My bullets are .309. I got the 3006 M Die as that is the caliber I load for. Its the long body .30 M Die. Some things come to mind that make me suspect I am on the wrong frequency here:

a. I should get a .309 or 310 expander , not use the .308 one I have now in M Die.

b.I should not use the .308 expander button on my Full Lenght resizing die, pull it off when I am resizing. If M die conditions neck , let the M did work the neck. No use doing it in the FL sizing die and then doing it again in M Die. I am overworking the necks of by 3006 brass.

I sure could use some advice here on the above concerns.

According to your estimates from another thread, you're shooting an inch at 100 yards at 2400 FPS WITH AN M1, WHY WOULD YOU MESS WITH IT??:D

Gear

[MBTcustom]

I make my own, and DocHighwall taught me the correct sizes to go for. If you are after accuracy, it helps but is not necessary per-say as many folks have figured out how to get good results without the M die. However, it is one more variable that I can control and not just take what I get and deal with it. All of those variables I can eliminate, makes my ammo better quality.
Besides, some of the die sets that I have bought (in fact the reason that I got started with the M-die in the first place) place as much as .006" of press on the bullet. The set that I got for my 358 winchester was like this and even with a copper jacketed bullet, I could visually see exactly where the base of the bullet expanded the neck. I dont care who you are that's just too much!

[Char-Gar]

The .308 expander in the M die will work just fine with your .309 bullets. If you bullets get larger than .310, then it is time to start thinking about a larger expander.

[MBTcustom]

If you need a larger expander for an M-die, PM me. I could probably handle that, but Char-Gar is correct in the above post.

[milprileb]

Gear: you are right: leave things as they are
but.... do I still need to use that expander button on FL sizer die?

[MBTcustom]

I would use it, but its not necessary. I just like the idea of getting the neck a head start for the M die. I intend to polish out the neck portion of my FL sizer die with diamond compound just so that it doesn't take it down so far, but that is going to be a time consuming project.

[Doc Highwall]

goodsteel, the diamond lapping compound will embed itself into the steel die causing trouble later by scratching the case necks. Maybe try I.D.grinding then a final lap for finish.

[dromia]

Since I use M dies for everything as all I shoot is cast, I have eliminated the expander buttons on the FL dies and just use a decapping rod with no expansion. Then, the M die with just enough expansion to start the bullet base and it has worked for me for years with no need to worry about lubing case necks and getting stuck expanders in my cases. Seems to work pretty well for me./beagle


Concur, thats how I do it and aim to have "M" die spuds that expand the neck to 1 thou under boolit diameter.

[MBTcustom]

goodsteel, the diamond lapping compound will embed itself into the steel die causing trouble later by scratching the case necks. Maybe try I.D.grinding then a final lap for finish.
Well, I suppose it might, if you started with 600 grit and stayed there, but a correct lapping job that works its way up in grit to 1200 will not leave much of anything to scratch the case. However, it might polish the necks a little.
By the way, thanks again for the info on M dies last year. You changed how I reload, and helped me fix one of the cussedest problems that I dealt with for years. Thanks!

[Doc Highwall]

goodsteel, Your Welcome!

[UNIQUEDOT]

do I still need to use that expander button on FL sizer die?

If you remove the expander button from the FL sizer your cases will last longer.

[Doc Highwall]

On some of my dies the expander ball holds the decapping in, so for say 30 caliber use a 7mm or smaller expander to hold the decapping pin in.

[milprileb]

My cast bullet world just got expanded by you guys. Things never in books
are learned here. Truly amazing the techniques you gents develop !

Thank you ~!

[Doc Highwall]

Just one BIG happy family.:bigsmyl2::cbpour:

[milprileb]

Now you guys got me spinning, maybe I ought to pull that expander button off my FL sizing die and use the M Die for my match 30 caliber loads with FMJ Match King bullets. Certainly, might get all my neck tension per round consistent? Gotta call Lyman or contact Buck Shot and see about a .307 dia expander for M Die.

M dies: I had blinders on.

[Char-Gar]

Now you guys got me spinning, maybe I ought to pull that expander button off my FL sizing die and use the M Die for my match 30 caliber loads with FMJ Match King bullets. Certainly, might get all my neck tension per round consistent? Gotta call Lyman or contact Buck Shot and see about a .307 dia expander for M Die.

M dies: I had blinders on.

It does nothing good for a rifle case to drag that expander button up and down through the neck. Many years ago, I stopped using them. I remove the entire decapping, expanding assembly from my dies and size (neck or FL) without them. I decap with a Wilson punch and base.

I don't shoot enough jacketed bullets to warrant having a M die made. But, it I did, I would.

I seat all of my bullets (cast or otherwise) with a Vickerman die or a chamber type hand seating die. Straight line bullet seating is important in my world.

I am not a high volume game shooter, so the times it takes to assemble precison loads is not a concern to me.

[1hole]

I happily used conventional neck dies without expanders in combo with M dies until Lee made their excellant Collet Neck Dies.

A slight bevel modification ground into my Collet Neck Die mouths leaves a slight case mouth flare to ease flat base bullet entry, somewhat like the M dies. And the flare seems to help reduce runout too.