Neck sizing the 454 case

[Warren4570]

Okay being that you all have a lot more experience than I when it comes to reloading with cast bullets I would like to ask your advice, thoughts opinions on neck sizing only with a 454 case.

I am working towards a lot of load developement for my SRH and a bit of experimentation as well.
After comin back from a successful elk hunt in Utah this year I took my fired cases and began decpping them before tumbling. I had done a pile of reading on neck sizing only for the 45-70 and reset the dies to partial size only ( keeping its fire formed shape and not overworking the brass).

When I ran the 454 cases through the lyman carbide sizing die I did notice that they get sized down appreciably from its fired size. I scratched my head a bit and put both fully sized and a fired case in the cylinder of the SRH and they fit easily. The fired cases are not tight in the cylinder either.
This lead my to wonder if I could neck size only a pistol case.

 

[Brad]

Rick suggested I do just that for my 44 mag SRH. Size the case just to where the base of the bullet will be once seated.
Works well enough for me

 

[Warren4570]

The reasons I am curious about this are a follows.
1 the cases would be fire formed to the cylinder and thus I would assume they would seal faster as less expansion is required when a live round is fired.
2 fireformed cases produce usually more inherently accurate rounds .... and the cartridge should be center better in the cylinder.
3 less work hardeneing on the brass case during numerous reloadings
4 possiblly less bulge when the cast bullet is seated in the case.

 

[Warren4570]

now How much smaller do we want the case mouth than bullet diameter for good bulet tension? .004?

 

[Warren4570]

Neck tension seems to be a critical factor from everything I have read so far too .... enough to get a good grip on the bullet but not some much you risk resizing it as you seat. Some even say the neck tension is more important than a very heavy crimp. I am always a bit concernd that a real heavy crimp may also resize a cast bullet a bit. Although I dont shoot much PB as of right yet.... still researching shooting GC bullets minus the check.

Have a 360 gr and 300 gr load to work on and test. The 300 is pretty much my go to bullet for now but the 360 for my 4570 that I got from Tom @ accurate sizes down the 454 nicely and when seated looks amazing in the 454 cases...... just sits maybe .030 shy of the full length of the SRH cylinder.

 

[Brad]

.004 isn't bad, I wouldn't want less.
I made an expander for 44 mag that bells the case mouths but doesn't open the case at all after sizing.

 

[Warren4570]

do you want the case neck a bit tighter Brad? Lookin for a taregt to check out when I start measuring later

 

[Brad]

I have mine as tight as the sizer allows. I can see where the lube groove is on a loaded round.
Rick is also gonna tell you to keep cases in groups all fired the same number of times. As brass is fired then sized it gets harder. That changes the neck tension a bit. Variations in neck tension lead to variations in bullet pull, that leads to larger groups.
I have played, in the past, with using a 44 mag expander to land 45 Colt. Just puts a bell on the case mouth. Lots of next tension.

 

[Warren4570]

the 360 gr mentioned in previous post.
As I dont load to full throttle hi pressure, limiting resizing cases with a partial to neck size only but with good neck tension should help case life and
hopefully help with a good accurate load.

 

[Warren4570]

Good info thank you. I will have to measure the expander when I clean the dies later prior to loading.
There is so much to learn in addtition to standard reloading skills when cast bullets are utilized.

 

[Rick]

Actually neck sizing revolver brass is beneficial for jacketed too, not just cast. Fire formed brass neck sized helps the rear of the case to better fit the chamber keeping the whole cartridge bullet included in better alignment with the center line of the bore. The looser (sloppier) your chambers the more it helps.

 

[Ian]

I do this on some of my .45 Colt loads using a steel sizing die. I only size enough to get me around .003" neck tension, but this is for standard pressure so less tension is needed. There is a limit to how much tension your brass will give you before it reaches its elastic limit and stretches....which is the point of diminishing returns on sizing smaller. You need to play around with your particular lot of brass and see what it gives you, I'd say .004" is about right though that thick, strong .454 brass might give you more if you ask. A bellmouth spud that rides the neck without resizing re: Brad's 44 expander is a huge plus for uniform bell and getting the bullet started straight.

Crimp is only icing on the cake. Tension, UNIFORM tension is where you get revolver accuracy. Rick did a mega-study of the .357 Maximum involving crimp and neck tension, his results were quite telling.

 

[Rick]

Crimp is only icing on the cake. Tension, UNIFORM tension is where you get revolver accuracy. Rick did a mega-study of the .357 Maximum involving crimp and neck tension, his results were quite telling.

Actually it was the 357 Magnum, not maximum.

Crimp Tests

FA 357 Mag 9”

RCBS 180 GC Silhouette @ 192 gr. (WW HT @ 18 BHN)
16.0 gr. H-110
Winchester brass
CCI 550 primer
Temp 70 Humidity 38%

All chrono tests 10 shots

1>
My normal profile crimp, second firing of WW brass, Carbide die sized
E.S. 30
A.V. 1518
S.D. 9

2>
Roll crimp, second firing of WW brass, Carbide die sized
E.S. 30
A.V. 1520
S.D. 9

3>
No crimp, second firing of WW brass, Carbide die sized, very slight bell
E.S. 30
A.V. 1528
S.D. 9

4>
Light profile crimp, virgin WW brass, not sized, not expanded, slight bell only
E.S. 26
A.V. 1532
S.D. 8

5>
My normal profile crimp, virgin WW brass, not sized, not expanded, slight bell only
E.S. 26
A.V. 1536
S.D. 8

Should be obvious from these tests that crimp does not hold the bullet, neck tension does. If neck tension isn't consistent neither is bullet pull, combustion, pressure or velocity.

Use caution with too much neck tension with cast, brass tension can and does size down the bullet depending on alloy and hardness.

 

[Warren4570]

I have to test again but the alloy so far shows a bhn of about 18-20 water dropped. I am going to cast a bunch n air cool them when in a couple weeks. Got my new sizing dies for the star from lathesmith so will be able to test them out too. The lee 300gr 454 bullet casts lubed sized to about 310.

Screwed up though and over sized the brass ... will have to shoot it all to fireform it again. But thats ok not like I am lookin for an excuse to pound off 150 rounds haha.

My 45-70 brass though is partial sized to about the right neck length with .050".
Thinking I may have to add a universal decapper or a 444 decapping pin to my 454 dies as the factory one is to short to decp and neck size.

What are your thoughts on say a lyman or hornady neck size die for the 45-70?

 

[Warren4570]

I think the lee 45-70 die resizes the case ad well even if set to neck size .... it's currently backed out about 2.5 turns from the shell holder.

When expanding I picked up an m type plug that fots the lee die for the 45-70. That made a huge difference in the load quality.
Picked up a chrony too as most everything has been an educated guess as far as velocity goes.

 

[Ian]

I size 45/70 Gov't brass in a 45/90 WCF die. I use the 45/70 sizing die for dedicated .45 Colt brass in my NEF single-shot (has a huge chamber/throat and likes .454" bullets). Mix and match, it's all about finding what works for your unique chambers.

 

[Warren4570]

Thanks Ian do you think i could successfully decap 454 brass in my 45-70 sizing die? Would be nice then neck size with the 454cassul die afterwards.
Temporarily eliminates a universal decapping die for now

 

[Warren4570]

Rick thanx for sharing the test you did makes perfect sense.
Usually just expand enough to start the bullet. Slight step... lyman m dies. bullet seats but shows a definite step at the base of the bullet once seated.

 

[Ian]

It will work just fine for decapping as long as the pin isn't too big for the .454's small primer pocket flash hole. Not all decapping pins are the same. Might even size the neck a little too, but probably not as much as you need.

 

[Brad]

My 45-70 die has often been used to deprime other cases without sizing.