If a person wanted to design a whole new case,with no common dimensions to another exhisting case, where does one start?

who will make the brass?
Does sammi or someone else have to approve it?
What do I need to know?
tell me any sound information that you have.

first of all absolutely no one has to approve it.....not even SAAMI

There's a lot of reasons to make a wildcat.....often it's to allow you to use an action you have on hand. Maybe to get around a law. Maybe to make a lighter rifle and still have a hard hitting round.......

Examples are the .375 Taylor, .416 Taylor, 6 x 45, .204-223 and many of the AI cartridges.

Let me say that merely trying to improve performance is a poor reason to make a wildcat.....it's just not a winning idea. Most frequently one wants a cartridge to fit an action.

I'll try to map out a process

1. decide on the end product and the starting case.

2. decide on the case you want to use

3. Buy custom dies to convert the case you have to the one you want. It may be a set of dies.

4. buy a chamber reamer slightly larger than the brass case you now have and use the reformed new case as a go gage in chambering.

5. chamber a barrel and install.

6. Using quickload or other starting loads based on other data (this is a hard one to do) you start load development. This is also somewhat risky as there's no load data to start with but there's some similar data. Quickload seems a good assist here. Start low and work up

That's about it....it's not cheap either....you'll sink abpout $500 over and above the cost of a new gun doing this.

p67
I suggest you start by doing a lot of reading.
Designing and Forming Cartridges by Ken Howell is a good start. There are may others related to the subject. Also a sound grounding in internal balstics would be very helpfull.
As to who would make the brass. Unless you can "sell" your design to one of the firearms manufactures and or a cartridge maker. You will have to make your brass(or pay someone to make it).
sammi will not be interested unless the design is being adopted as a "factory" round. Again unless you want to pay for the testing and standardization process.
Ideally you should know every aspect of your design and how it will work and be used.

Goog luck with your project

muck

.

quote:

Originally posted by Woodjack:
If a person wanted to design a whole new case,with no common dimensions to another exhisting case, where does one start?

$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$

Hog Killer

quote:

Originally posted by muck:
...Designing and Forming Cartridges by Ken Howell is a good start....

Hey muck, Don't take any offense at what I'm about to say, because they are not intended to denigrate "you" at all.
---

Hey Woodjack, It isn't hard at all to Design a cartridge, the hard part is mostly getting the Cases made, Chambers Cut and Dies made for it. That is why most Wildcats are based on other, already existing cartridges.

I used to think "howl" knew what he was talking about, but soon learned he simply makes ANYTHING way more involved than it needs to be. I even coined the phrase "howl CARET Factor" (Complicating Any Relatively Easy Task). Not sure why he does it, but it has always been impossible to get a straight answer from him. And he really wants everyone to kiss up to him which some folks seem to enjoy. Since I can see through howl and don't do the kissing up, we don't get along well at all.

I'd recommend you get a copy of P.O. Ackley's Handbook For Shooters & Reloaders which is a two volume set and look at all the Cartridges listed. The information is a bit dated and most of the Loads were based on "IMR" Powders which have changed slightly since the early `60s. So a person has to be extremely careful with the Load information.

Cartridges of the World is another book that would help you see what has already been done.

The other thing I'd recommend is a good Ballistics Software Program. I have Wayne Blackwell's Load From A Disk and it is OK, but not as flexable as Quickload that Vapodog mentioned. With this Software, you can do "What if...?" type changes to all the dimensions and volumes, and often get a relatively reasonable "estimate" of how it would work in reality. Not 100% perfect, but it will get you in the Ball Park.

Hot Core
I don't see anything offensive in what you have said. Mr. Howell does seem to go the long way around in his writing. That said, the book I mentioned is a good source for it's many dimentioned cartridge drawings.
The books/software you suggested are all good resources also(and in my library too).
I think reading on the subject is the place to start. And the more diverse your resources the better understanding you may achieve.

muck

Hey Muck, Thanks for understanding. And I do agree with your assessment of howl.

He used to be the Editor of Rifle and Handloader magazines and he had me completely fooled about his actual knowledge.

All of a sudden he showed up at HA when I hung around there and I thought we were surely fortunate to have such a knowledgeable person join the group. Rather than list the details, I'll just freely admit that howl had me completely fooled. If it hadn't been for Bob Hagel, Ken Waters and such writers, howl would know nothing at all.

And he even tries to "hide" that his Doctorate is in Theology. It has NOTHING at all to do with Engineering, Physics, Math or Ballistics.
---

howl is at 24hourcampfire. If you want to see why I have such a low regard for him, watch how he answers the Beginners that don't immediately kiss-up-to him. Absolutely pitiful!

First gather up a large sum of money. If you're new case has a unique dia, then you're going to have to shell out for all the tooling for the brass co, and it will be by far the biggest expenditure you'll have. As far as who to contact for brass, there is Starline, though there are limitations on what size they can handle, and you'll have a pretty good sized initial order. I'd expect to have to spend many thousands of dollars for custom tooling and a run of brass.

The other option is Dieter Hornbear in Germany. Dieter can do about anything, but I'd expect it to take upwards of 2 years to get your brass, and a pretty good outlay of cash. Contact Rob on the big bore forum, he designed the 600 Overkill and had Dieter make the brass. The other option is getting brass turned from rod stock, this is cheaper for a small run, but you are limited on max pressure.

Do to the difficulty and expense of creating a new case, most of us look at existing brass to neck up or down, or shorten. I even contacted Starline about making a run of 5.56X50R basic brass, think really long 357 max case, and they weren't interested even if I get a minimum run of 10,000 cases.

After you have a parent case at hand, it's just a matter of having a custom chambering reamer cut, and custom reloading dies made. Then commission a gunmith to build you your gun.

Whatcha thinking about making?

I know there's some folks machining brass and am not too sure of it's suitability.

Anyone know about this machined brass. They machine basic brass and then form it in dies.

As Paul H says, it's very limited in the max pressure it will handle. Not much above black powder pressures, in fact.

This is due to the hardness in the case web area being limited, to that of the bar stock it's made from. Cartridge Brass can only be hardened by cold deformation, and the number of steps involved in drawing cases make it easy to get the desired hardness, by selecting the annealing point/s in the process.