45-70 neck expander die

[oldbear1950]

I am really confused. If I size the case of a 45-70 fired case, and have a bullet seating die , what does a neck expander die do?
I did not think a 45-70 case has a conventional neck as do bottle neck rifle cartridges.
I have loaded 223 rounds back when 223 and 5.56 were the same cartridge.
Back in the 1970s and early 1980s.
I have also loaded 30-06 rifle cartridges and 308 Winchester.
But compared to those rounds did not think 45-70 had a neck

[mehavey]

The sizing dies reduces the case inner diameter somewhat beyond the diameter of the eventual bullet being seated.

The expander opens it up again from the inside to accept that bullet, while simultaneously ensuring uniform residual neck tension.

[Hawg]

Neck is the wrong term. Case mouth is what the expander die opens up. If you size a case a bullet no longer fits. The expander opens the mouth enough to get a bullet started so the seater die can press it in without damaging anything.

[Mike / Tx]

So the 45-70 is closer to loading long revolver rounds than bottle neck rifle. When you size a straight walled case you then use the expander to expand "JUST" the mouth and a slight bit of the neck. Usually you will also give the lip of the case just enough flare to allow a bullet to sit atop before seating anc crimping. This step is even more important when using cast bullets. A failure to give enough of a flare can result in shaved lead, shaved powder coat, and also crushed cases from sticking or unsquarely seated bullets.

[mehavey]

Neck is the wrong term.

FWIW, I'll term the shank depth portion of the (otherwise/mostly) straight wall case as the "neck".
"Mouth" is just the ...well... mouth.

The case "neck" (see above) gets expanded.
The mouth (see above again) gets flared.
Two different actions to two different parts of the case.

Burma Shave.....

[Hawg]

Originally Posted by mehavey

FWIW, I'll term the shank depth portion of the (otherwise/mostly) straight wall case as the "neck".
"Mouth" is just the ...well... mouth.

The case "neck" (see above) gets expanded.
The mouth (see above again) gets flared.
Two different actions to two different parts of the case.

Burma Shave.....

ok

[totaldla]

The real issue is "do you need it?" - in my experience, no.
It does reduce runout, but other than cartridges looking pretty, l never saw any improvement in accuracy with a Marlin Guide Gun.
It does make seating a bullet easier if you have a press where you can't let the bullet&casing slide up through your fingers into the seating die.

If you need to use .460" bullets, ( wonky barrel), the die will eliminate bullet shaving.

[mehavey]

^^^^ Add to above ^^^^
IMHO: All cast -- whether bevel or flat -- needs the expander/flare

[Jim Watson]

Word games.

If you are loading for a repeater, the case should be sized, expanded, flared, and crimped.

Some careful Sharps shooters will size lightly if at all, flare, slip fit a bullet, and even leave a bit of flare to center the round in the chamber.

[oldbear1950]

I have loaded 45-70 cartridges for Marlins, both RUGER # 1s, and RUGER # 3s.
Now am loading for a Henry, with the brass frame, loading gate, and tube load, and 24 inch octagon barrel.
Seems so much like a Marlin, I would think the same loads would work, at least that is what Henry says.
My dies have always had the sizing/depriming die, expander die, and seating/crimping die. I have used a separate factory crimp die, ever since I could get one.
I just never saw a 45-70 neck expander die

[oldbear1950]

I was stationed in Kodiak, Alaska twice in the US COAST GUARD, and carried 45-70s at the recommendation of the Alaskan fish and game department.
Started loading my own up there, cause unless you wanted to wait a month or more for ammo, you had to load you own or not shoot

[oldbear1950]

Course that was back in the 1970s and 1980s

[44 AMP]

Case neck is the correct term. This includes the mouth, and the neck portion that grips the bullet. Actual straight cases and cases with a slight taper that we call "straight" have necks. ALL cases do, though it isn't as clearly defined as it is on bottle neck cases.

The .45-70 is loaded the same way all "straight" cases are loaded. The case is resized and this reduces the inside diameter of the neck a bit too much for proper bullet seating. The neck interior diameter must then be expanded to seat the bullet.

Bottle necked cases do this with the expander ball on the decapping stem, as the case is withdrawn from the sizer die. That method doesn't work with straight cases, so a separate die is used. The expander stem both expands the inside of the case neck to fit the bullet, and (If adjusted to) flares the case mouth to make bullet seating easy, and square, and the seater die removes the flare, finishes seating the bullet, and crimps (if adjusted to do so).

[totaldla]

First of all, i am unaware of any die set that includes a neck expander - I bought one from Lyman ,(,M die).

Second: the 45-70 is not a straight wall cartridge - it has taper, just not much.

Third: When loading warm loads for tubular magazine leverguns, it is absolutely critical that you maximize neck tension (mitigate recoil induced bullet setback). So don't think that you need to do major neck expansion. The most you need is small step to center the fat cast bullet during seating. What guys get away with when loading for a single shot won't work.

[mehavey]

All complete pistol/rifle straightwall (notwithstanding "tapered") reloading packages are 3-die sets
https://www.midwayusa.com/product/1011241272?pid=507130
(an 'M' die is just specialized expander -- more often used for bottle-neck/cast)

And you do need neck expansion -- especially for cast -- if you are seat the bullet uniformly straight
and (in the case of cast) w/o deformation and/or swaging effect.

.

[stagpanther]

Third: When loading warm loads for tubular magazine leverguns, it is absolutely critical that you maximize neck tension (mitigate recoil induced bullet setback).

Usually a heavy crimp into a cannelure in my experience.

[44 AMP]

When loading warm loads for tubular magazine leverguns, it is absolutely critical that you maximize neck tension (mitigate recoil induced bullet setback).

I have run warm loads (400gr @ 1800fps) from my Marlin, no special prep just the RCBS dies (including expander) adjusted properly and with a heavy crimp, without problems in my rifles. No "maximizing" of neck tension was needed, just normal loading and a proper crimp.

So don't think that you need to do major neck expansion

.

The expansion done by the expander stem only returns the undersize case neck ID back to the proper size to correctly grip the bullet. Without doing that, you might wind up collapsing the case when you try to seat a bullet. And without at least some degree of flare (to include a proper chamfer of the case mouth, you can collapse brass, or shave material off the bullet, along with not seating it straight. Not something that will always happen, but something entirely preventable using the standard loading practices.

The .45-70 is a slightly tapered case, it goes from .480" at the case mouth to .504" at the head. It is not truly straight, but it is loaded the same way straight wall cases are loaded.

[totaldla]

I think there is some confusion.
There is "expansion" done by the powder-through die in a Lee set.
Then there is "expansion" done by specialized dies like the Lyman M.
The latter creates an over-expanded region centered in the case neck that allows you to set the bullet in place and be assured that the bullet will stay centered while being seated - at the expense of neck tension.
Only the first 0.8" or so of the casing is hanging on to the bullet (thats the effect of taper).

Also, it is a good idea to check for bullet setback in a tubular magazine (load full, shoot one, measure the rest).

Jacketed can move more than cast as cast usually has a pronounced crimp groove that the Lee Collet can stuff brass into. But cast is more slippery and the crimp alone might not hold.

[oldbear1950]

I have to be honest, I always used RCBS, 3 die set to load up my 45-70 cartridges.
In fact going thru all my gun stuff, found a complete box I loaded up in 1987, while stationed in Kodiak. So far they fired with no problems.
I did not know if they would still be sound after all these years. But so far, no problems feeding, firing and ejecting from my Henry lever gun. Guess I did something right back then.

[mehavey]

The latter creates an over-expanded region centered in
the case neck that allows you to set the bullet in place

I was about reply w/ a correction, but realized that what was meant by "over-expanded" is really the last stage/slight mouth flare.

(BTW: Most pistol/straightwall die sets actually use the "M" die design now... but don't call it that)

[44 AMP]

The Lyman expander plug has a definite "step" at the top (where it meets the expander stem). Other makers use/have used a taper to do the same thing (flare the case mouth) but I think the step is a better method.

The downside?? It has to be adjusted properly, and if you do it wrong, you can overflare the case mouth, possibly so much it won't enter the seating die, or even enough to possibly crack the brass at the mouth. And, of course, for uniform results you need uniform case lengths. There's no free lunch.

The Lyman "M" die refers to the die body used. It is simply a die body bored "open" so no part of it touches the case anywhere. It is used to hold the expander stem, and is what Lyman puts in their 3 die sets.

You could, if you wished, take an M die body and install a decapper stem, and have a Lyman "universal decapper die", but the M die body is most commonly used with the expander stem.

Then there is "expansion" done by specialized dies like the Lyman M.
The latter creates an over-expanded region centered in the case neck that allows you to set the bullet in place and be assured that the bullet will stay centered while being seated - at the expense of neck tension.

Only if you adjust the die to do that. You can set the stem to produce no case mouth flare. Or just the tiniest amount, or all the way to making an oversize "cup" allowing you to just set the bullet in place, loosely.

ITs up to you, how much do you want to work your brass?

[totaldla]

Look at the rifle dimensions to understand what the M die does. It does more than flair.

[mehavey]

I'm calling the 2nd section "flare" to just over bullet diameter
to permit bullet seating about dime's thickness into the casing.

"3rd" stage is beyond what I would normally ever use.

[44 AMP]

Ideal reloading tools which later became Lyman, go back about a century and a half, and they've been making expanders for about as long as they've been around, and, they work.

My guess would be that they know what they are doing.

Perhaps they don't give the tightest neck tension possible, but what they do deliver is quite practical for most of us, I think.

[totaldla]

The 45-70 performance has changed a lot in the last 40+ years. It is easy to overlook the difficulty of keeping a 400'ish grain bullet in place when the carbine in use is generating 45-50 lb/ft of recoil.