For big long cases our testing is showing that the 416 easier to get powders to work with, less problems ..
Maybe building a target gun,don't have 375 barrel all ready, maybe go 416....
We got cases, 416 HE and 416 HSM, as well as 375...
CEB and others will have bullets...CEB will be doing .416 in 450gr, 475gr, 500gr, 525gr and 550gr
Got sent 5 thick sided sample cases, same OD base as 585/375.416 cases, same belt, just .180" longer,
did a 416 HE, chambered extra barrel , cases stick over 50k. They have about .042" total taper, .021" per
side, when I necked couple to 416. That is a lot of taper , twice the taper of my 416HE...hanging up at 50k..
I could maybe go to 65k with these if we made taper with ..012" - .016" more taper to each side, but that is
no way to build target cases. I'd have to crunch down case shoulder diameter. And would look like 30-30.
And crazy part is, the case has enough brass material to thin up sides and stretch them way out to 4 or
more inches,, They weigh 150 gr more than our 585/375/416,, but with real thick sides they actually
hold less than our 416 HE with thin sides, that is .180" shorter...Our case does 65k ok without sticking..
And we can make super long 4" cases work if we had means to get them built, as we have
15 powders slower than HBMG.Here is pic of thin and thick sided cases, sectioned for comparison.Ed..
Here is a drawing depicting the layout of thick and thin sided cases,
like my 585/375/416 HE thin sided ones and the thick one in picture.
And my 585 case is not perfect, as where it transitions from the
heavier corner to the side it isn't gradual, so case separates there
shortening case life. There are others made that way including brand X.
The dotted line is what it should be............
Others have sent cases to section and look at, that are built thick sided and they
stick also for the folks, If a longer case with about 5 sq in of side surface sticks and
don't spring back, the coefficient of friction is about .01 then the pull needed to move
it is 2500-3500 lbs..That is for big cases with normal amount of slant to the sides.
Here is picture of six nyati and gibbs size cases sectioned.. the5th one is present 585 HE
and 6th is thick sided version. 1st 600 OK which essentially nyati basic case left straight, belt added
In the picture the nyati gma is one we built most of our first 585s on. Before we had factory run.
Reworking made it in size that is my 585 HE, but that brass had the sides of perfect thickness,
not too thick, but thin without sharp transition my new factory 585s had, they last forever as 585s......
Fourth one is an older nyati case I used to make about 10 of my 585s from,had thin sides, heavy corner
and sharp transition from the corner, tested 20 years ago, and they would separate after 4-6 hot loads
as 585s, my factory 585 with right powders, as a 585 will get 10 hot loads, and necked down to
416/375 4- 6 hot loads, right powders used, Moderate 577 equivalent, factory 585 at least 20 loads..Ed.
Guy sent thick sided 375 case, next size base diameter up from Nyati.He said,
'Yes I ran them in a ___________ rifle built by ____, the best I
could get was 44000 psi, any more and they were stuck''
Big bore guys. other forums over the years related that trex/african case in 585
size, thick sided cases, stuck when they loaded them over 45k psi.
Another just sent us, thick sided 375, long case, same base OD as our 585 HE,
416 HE, 375 HE, and Mitch's 375 Lethal, and the thick ones stuck over 45k psi.
Now you can fill those cases up, with ultra slow enough powder so they won't
stick, but powder is too slow for max speed. Might get a little more
speed, with thick sides case, but case got to be 4- 4.5 inches long..
. Anyone needing a sectioned case of the ones I made the first of my 585s from,
contact me, if they want to get a general idea of what case side thickness should
be, in Gibbs size cases on up to about trex and 375 VM size case diameter.
Here is pic of our 585 based case next to brand X and thick ones, both have
same sharp, thinner, corner, where transition from heavy angled corner, to the
side, the carbide draw rod could easily be reshaped with diamond wheel,
just by grinding off sharp transition corner. Then sides would be perfect.., .
Here is picture of 416 HE in a Choate target/varmint stock guy is doing,
using long action BSA U9 action.Setting in stock ready to do bedding..Ed