25 October 2011, 11:00
ShortandFatIntroducing the 458 JCE Super Short
Gents
Firstly I must thank Michael458 and Jeffe for the inspiration and experiences I've learned from them for this case design.
In Australia we really dont have access to all the wonderful B&M rifles from Michael and SSK so we had to go about making our own. And importing them from the USA is nuts, between your State Department and our Customs and Firearm registry ...... forget about it.
About 5 of us already owned WSSM rifles that needed a face lift so we all brought cheap 458 Adams and Bennett barrels and set to work on designing a Super Short 458.
I was given the duties of case design and getting the dies made up. I'm the J , Carl is the C and hes the muscle and load development man and E is Evan pictured below he's the Businesman thats how we got "JCE" but a few Aussies are calling it the "458 JuiCE"
I cut the 300 WSM case off at the shoulder at 1.675 and settled on this length, but realised there was a slight LIP on the inside from the old shoulder, so I got around this by turning the lip off or using 7mm WSM brass because it's taller
The case has been improved and taper has been blown out to 10 thou, the case is .555 at the base and .545 at the shoulder,
The shoulder angle is set at 35 deg I did this to keep the shoulder at WSM specs and most reamer makers have 35 deg tooling
The Neck is .315 thou long to give it a little more grip on the projectiles
To avoid pressure I also stretched the freebore to 250 thou, this hasnt noticably effected accuracy. And has allowed us to hit some pretty impressive speeds in preliminary tests with very little noticeable pressure signs.
Finally we gave the job of reamer and gauges to Dave Manson and I have to say I truely love his work, he's always been a gentlemen to us and very quick to whip up reamer drawings and offer advice
I got CH4D to make the dies, they have made great custom dies but from order to dispatch it took about 7 months, In that time, one of the other guys in the project sent fireformed cases to Hornady and had 5 sets of Hornady dies made before our 5 sets of CH4D dies arrived.
Case capacity has come up at about 30-06 capacity at 67.7g of water
All guns to date have been built on Winchester rifles. mostly PF but there is plans to build one on a Browning
We had some trouble with feeding from the left side, I have examined the magazine box in the Winchester WSSM rifles and with some slight bending of the feeding part at the front of the box the problem has been solved.
One guy using Tally mounts has broken two rear screws and has had to retap the action to accept 8-40 instead of the factory 6-48. My Leupold mounts with rear windage screws just will NOT hold the rear rings they keep sliding forward and I've wrecked / deformed 2 sets of rings, the recoil is more than most of us expected from the small case, but maybe it's because the rifles are so light and small
Powder of choice, we dont really have access to LILGUN here, although I'm told it's now in Austtralia, but we have have a powder called AR2205, it's very fine and dense and we are producing unbelieveable velocities.
For example I can load 51g of AR2205 behind the 300g Speer UNICOR with at least 3 grains of powder more to go at 2450fps from a 19 inch barrel.
To date we have or are in the process building 9 rifles and lots of interest being shown
Here's a few photo's and I'm happy to answer any queries
regards S&F
25 October 2011, 13:23
boom stickSweet!
Sure is Short and Fat

Now all the world needs is a 400 version

25 October 2011, 16:23
michael458S&F
I should have known you boys were up to something down there! Been very quite it seems, so I should have known you were up to something! Looks like you got some new toys for the boys!!
Busy I see--Looks great! Congratulations! For sure the best use ever for that WSSM action.
I also see some of those wonderful brass noncons you guys are working with down there too! Ours are proving out to be incredible in the field on everything from deer to hippos!
The juiCE is cousin to the 458 B&M, gotta be good! Barrels are a little long however! HEH......
It's a fine thing, I will be bringing Super Shorts to Australia next August and busting buffalo with them, bringing all of them, 50, 475, and 458. All with BBW#13s and North Forks.
Michael
26 October 2011, 09:23
NelsdouVery cool!
I made a 8mm wildcat on a cutdown 284 case (reamer by Dave Manson) and found it can push the heavy 8's surprising well. The short & fat powder column must be efficient.
03 November 2011, 03:56
ShortandFatGents some load development over the weekend
There pressure signs are a bit confusing, bolt lift gets slightly stiffer, and top loads are pushing it, but primers stil very rounded, but this I'm sure is partly due to the large freebore we have
Using ADI 2205 - 300g Jacket hollow point 19 in barrel
47 - 2191
48 - 2270
49 - 2320
51 - 2411
52 - 2483
Using LILGUN - 300g Jacket hollow point - 18in Barrel
48 - 2481
49 - 2492
50 - 2518
51 - 2538
The efficiency of this little fat case is unbelievable.
regards
S&F
03 November 2011, 04:42
ShortandFatOH and as a point of interest
The 458 JCE is definately easier to create from 7mm WSM brass
The 7mm case is taller thru the body and the shoulder is higher at 1.7018 as opposed to 1.675
If I could redesign the 458 JCE again I would have based it on the taller 7mm case at 1.700 and got more useable case capacity
regards
S&F
07 November 2011, 05:05
ShortandFatMore data on the weekend using
ADI 2205 powder & LIL'GUN
Test gun has an 18 inch barrel
Projectiles - Barnes 250g TSX
AR2205
50g 2469fps
51g 2491fps
52g 2524fps
53g 2551fps
LIL'GUN
50g 2549fps
51g 2574fps
52g 2596fps
53g 2649fps
I was told pressure signs did NOT, look excessive, but again the long freebore could be hiding this.
These are pretty amazing figures for a small fat case.
08 November 2011, 05:40
RandyBS&F,I"ve been working on mine for about a month now. It is a little different than yours. I settled on 1.650" for length but have a .400" neck length. That neck allows me to seat the 300gr Barnes TSX to the base of the neck- shoulder junction and still feed well. One thing I discovered accidentaly is you can use 300 WSM brass just don't cut it before you form the case. This actually elongates the brass and pushes that lip ahead of the trim line. I then neck turn to fit the chamber and clean up the donut. Also in your original post I have to inquire about the fired rounds sitting in the lid of the blue box. They appear to have a bevel at the mouth? Your velocity numbers look good and I think your are getting the most out of it. Have fun, RandyB.
09 November 2011, 07:57
ShortandFatquote:
Originally posted by RandyB:
S&F,I"ve been working on mine for about a month now. It is a little different than yours. I settled on 1.650" for length but have a .400" neck length. That neck allows me to seat the 300gr Barnes TSX to the base of the neck- shoulder junction and still feed well. One thing I discovered accidentaly is you can use 300 WSM brass just don't cut it before you form the case. This actually elongates the brass and pushes that lip ahead of the trim line. I then neck turn to fit the chamber and clean up the donut. Also in your original post I have to inquire about the fired rounds sitting in the lid of the blue box. They appear to have a bevel at the mouth? Your velocity numbers look good and I think your are getting the most out of it. Have fun, RandyB.
Randy
We have been using 300 WSM brass all along but have found because 7mm WSM cases are taller to the shoulder, there is NO inner lip like 300 and 270 WSM brass has.
If we leave our brass at 1.675 there is the slightest INSIDE lip from the old 300 WSM shoulder, I find I can get most of this turned off with a simple debur and trimming it to 1.665, but its not nessessary with 7mm brass.
The cases in the photo only have a slight bevel and crimp but nothing else
To trim brass I simply put the case into an electric drill chuck neck first and spin it on a hack saw , square it up with a belt sander, debur, and run it thru the full length resizer to form, then trim to final length with a standard RCBS case trimmer and 458 pilot.
I actually tried to blow out and form the trimmed case with shotgun powder, oatmeal and an ear plug, but just could NOT generate enough pressure to form it
regards S&F