Hello All,
I've been becoming more and more interested in the wildcat and reloading ares lately. I haven't even yet purchased any equipment but have been reading numerous books. I was wondering if anyone could point me in the direction of a book, web-site, or other source of information explaining what goes into the design of a cartridge. Such as, what the variations of shoulder angle, diameter, length, etc. would produce. For example I hear a lot about efficient and inefficient designs.Feel free to be as technical as you would like. Anything I don't know the meaning of (much) I will research to the best of my ability.
Thank You
-Josh

There are quite a few books out there, but the two I would recommend most are:
a. P.O. Ackley's 2-volume set on wildcats, and
b. Ken Howell's book Custom Cartridges.
Although Ackley's book is dated and the velocities should be taken with tongue in cheek, you'll get some interesting info.
Ken Howell's book is an excellent guide and provides drawings of the cartridges.
The book on Wildcat Cartridges from Wolfe Publishing is fun too, just to look.
My problem is that every wildcat cartridge I've had in a rifle has become a factory round... .22-250, .25-06, 7mm-08, 6.5-08, 7STW, .338-06, well you get the idea.
My latest one, brought on by forum members RIP and Boom Stick is going to be a .395 Ruger.

Changed Waters to Howell. Was thinking of another wildcat, now a commercial cartridge, that I own...7-30 Waters.

Teroenza (what does that mean, in english?)

The basic principles for designing a wildcat, we'll put aside the mere ego gratification some use, that will be used by others twofold:

1. First, tell me what for?
what are you going to shoot with it, how far away, how big a package do you want?

As an example, and not to toot my own horn; I wrote for Precision Shooting Magazine for about eight or nine years.
Primarily long(er) distance live varmint shooting...Rockchucks and Prairie Dogs and Coyote. My goal was flattening the trajectory at longer yardages. The simple answer was a bigger case for caliber, to utilize the newer slow burning MilSurp powders coming on the market. I tried the other answer, getting a higher BC bullet made, and failed miserably. It's a multi-thousand dollar deal, making a set of bullet dies and getting bullet jackets made, etc.

Principle One: a bigger case lets you burn more (slower)powder for velocity increases that may go as high as 1/4th of the case capacity increase. Double the case capacity, add up to 25% velocity gain. I took the 6,5x68Schuler case, necked it to 25 caliber and blew most of the taper out and put a 35-degree shoulder on it. Ninety grains of ball powder capacity. 110gr VLD bullet at 4000fps! My second attempt was just a rework of the 22-284 design. 80gr JLK VLD bullet at 3600fps. The third was a fit of insanity, an Ackley Improved version of Bob Forker's 1964 experiment for NASA to replicate the effect of meteorites striking the space capsule...the 22-378 Ear-Gesplitten, Louden-Boomer. They shot copper plated steel 40gr BB's close to 7000fps. I stuck with the 80gr JLK (which Sierra copied) at 4850fps and wore out a barrel every 120 shots.

Principle Two; make a more efficient version (read shorter and fatter as a rule) to utilize a standard action.
The WSSM's and SAUM's are good examples, but the tradeoff is fewer cartridges magazazine capacity. The new 375 Ruger may be the best example, 375H&H in a standard, 2.5" case length.

The other, is to fill a void, real or imagined, in the field. The .204 Ruger is a good example here, as is Boomie and RIP's ongoing efforts with the .395" caliber for DG. These guys figured there was waaaaay too much space between 375 and 416 to suit them, so we have the .395 coming to life the first half of the year.

Probably way too much information, but I think that this covers it pretty much.

Rich
DRSS

quote:

and wore out a barrel every 120 shots.

That is a blow-torch!

Ken Howell's book esigning and forming Custom Cartridges has alot of info. Sinclair has had the book in their catalog.

Thanks everyone for the recommendations and information. I currently don't have a specific round or task to accomplish and am just beginning to learn. Hearing about wildcatting and the plethora of cartridges out there sparked my interest. I've also been looking into the unique designs such as VlD bullets and very high velocity. Thats incredible about the AI 22-378. Experimenting and learning more has always been appealing to me, even if I don't actually have a use for such a design.
Again thanks and I will try and track down those books.
-Josh

Also, teroenza is an extremely obscure priest from the star wars universe. I've been using it as a screen name since the seventh grade, and to this day have no idea how I encountered it.

teroenza,

Ken Howell's book is great, so is this one by Fred Zeglin:

Click here

to get this book


and get a great read on many practical aspects of this hobby.

Fred Zeglin is a wealth of practical experience. Good book for novice and "expert" alike. It deals with .10 caliber to .50 caliber wildcats, even has a page devoted to the 470 Mbogo.



May The Force be with you!

Thank you as well RIP. Now I have to decide which to order first
-Josh

I would recommend getting into reloading first.
Take rounds you already like and reload for them, tweak the bullet/powder/charge combo, take care of cases, all the stuff that comes with wildcatting without delving into that whole other world of cartridge design and near-blind load development.
You will likely discover either that you hate reloading and a wildcat is definitely not for you, or you love to reload and want nothing more than to get more and more into the fringe of DIY shooting.
THEN look at what bullet you want to go how fast and what case options there are, and what action you want to do it in, etc.

Yes, get into making quality loads of your own for something standard and accurate, like a 308W or a 223R; something along those lines. Then figure out what game you want to hunt, the caliber, and the yardage you want to shoot out to(aka velocity or muzzle energy level). Those three points will give you either a factory answer or an idea for a wildcat.
Maybe something simple, like you decide you want a 25 caliber rifle for Elk and Black Bear. So you decide you also don't want a belt or major case forming hassles. That leads you to, say, a 25 WSM. Neck a 7mm WSM down and giddy up grandma!!
The planning process is half the fun.

Rich
DRSS

Yes, I agree starting reloading is the natural way to get started. No sense in making wildcats if I don't understand how the originals are loaded.I'm just jumping ahead in my mind here.

quote:

The planning process is half the fun.

Indeed

I have been gathering numerous cartridges for a collection and that has sparked my interest.

Thanks
-Josh

Cartridge design is a fascinating subject that probably deserves more attention from shooters. I see too much emphasis given to just jacking up case capacity. Far too little IMO, on design, efficiency, case/bore balance, etc. We probably have way too many calibers as it is, but new stuff is part of the fun & allure of rolling your own. You got some good advice for your design library here already.

Josh- having designed the 257DGR and having about 5 other ideas laying on my reloading bench, it is a very fasinating venture to put ideas and drawings into motion. When the design works and actually works better than expected it really becomes fun. One of the major problems with case design is that 95% of the shooting public doesn't care about why a particular case design is better. My 257DGR is designed the way the entire 308 family "should" have been done. The problem is that there is not enough significant difference between a 243 Win of which millions have been produced and the much better designed 244 DGR(think of a full length 6mm br) to replace or even produce the 244 DGR. The 30 degree shoulder, longer neck, slightly larger shoulder diameter would make the 243, 260, 7mm08, and 308 all a "better" designed case, but it will probably only happen in my shop and myself and a few other "nuts" will be the only ones to ever enjoy the results. Who cares if only I like it is the motto of every die hard wildcatter. The desire to build and try something different or unique appeals to some and not to others. I for one enjoy the process.


www.duanesguns.com

just checked out Duane's website. Well laid out, and definitely worth a cruise to.

Rich
DRSS

Thanks for the information. People seem to want the biggest or fastest no matter what. I see there is a great deal of information and work going into these besides adding space and necking up or down. That and I can see how nice it would be to be able to admire a cartridge as unique as your very own rifle.

Thanks
-Josh

DuaneinND: I agree with Idaho, very beautiful rifles.