wildcat development

[rtracy2001]

Not that I have any heretofore unheard-of ballistic ideas, but I have a few things nagging me that I want to explore further. As this will be totally new territory for me, I would like to do some research first on the process of developing a wildcat cartridge. Anyone have any suggested reading on the subject?


For the most part I intend to reform existing cartridges by necking up or down and changing the shoulder angle/profile. Any suggestions on manipulating the brass in this manner? Would I be best served by custom machining a sizing die for each iteration, or is there another, simpler way?

[Nelsdou44]

I'd suggest getting a copy of "The Handloader's Manual of Cartridge Conversions" by Donnelly & Towsley, published by Stoeger. It has quite a bit of info on working brass and a lot of cartridge dimensions. Another is PO Ackley's books volume I and II, "Handbook for Shooters & Reloaders". Do a 'net search for those; they are classics.
Another is "Cartridges of the World" by F. Barnes. These will give you a pretty good idea what's been done and what works. And if you get bored with those you can read about my wildcat project over at http://www.thehunterslife.com/forums...ad.php?t=15105

Nels

[82nd airborne]

What specifically do you have in mind?

[frankenfab]

You can do alot by using different dies, but you are limited on the shoulder angle by the angle of the dies on hand. For example, I created the wildcat "357 Automax" by taking a 10mm magnum case and shoving it into a .357 Sig sizing die to make a neck for .358 bullets. There is only one of these rare dummy rounds in existence!

Sometimes things are done this way, and the cases get the new shoulder angle from being fired in a chamber with the new shoulder angle. from there they can be reloaded by neck sizing until they reach the point where the shoulder needs to be pushed back a smidge.

There are limits on all this stuff, such as how much you can reduce a neck size in one pass, changing shoulder angle changes neck length, overall length etc. The first book Nelsdou44 suggested, as well as the others, would be of great help, I'm sure.

I have just played around with it some myself.

[rtracy2001]

I've read Cartridges of the World. great book. I'll look into the others.

Mostly I have a few things that are "now why didn't they do this instead?" type of things.

Another quandry has been a .30x57mm. Just a 8x57 Mauser necked down to 30 cal with the shoulder angle increased a bit and maybe with a Weatherby radius instead of a standard shoulder design. The hope is to match or beat '06 in a shorter package. The 308 win keeps up with everything up to about 180 gr bullets, but I want to see if I can beat the '06 in the 200 to 220 gr range.

[Bullshop]

Maybe you should try the Herters double cyclone shoulder. Jacque said it improved performance of all standard cartridges. Maybe you could go him one better and make a triple cyclone shoulder.
Bottom line , any cartridge delivering higher velocity with equal bullet weight than that of a cartridge with greater capacity is doing it with higher pressure.
There may be a slight exception as in when you find a particular barrel gives higher than normal velocity. For instance if you had a particularly fast 308 and were shooting against a rather slow 30/06. But if then that 308 was re chambered to 30/06 it would then also be a fast 06.

[Doc Highwall]

Do not forget the Rocky Gibb's cartridges with the extended flash tubes for higher velocity.

[Doc Highwall]

Don't forget the Rocky Gibb's cartridges with the extended flash tubes for higher velocity.

[rtracy2001]

Bottom line , any cartridge delivering higher velocity with equal bullet weight than that of a cartridge with greater capacity is doing it with higher pressure.

Yes, the pressure would have to be higher than standard '06. Note that the 30-06 has a SAAMI max of 50,000 cup and the 308 Win has a SAAMI max of 52,000 cup. The 8x57 has a SAAMI max of 37,000 cup due to the risk of mistakenly chambering a JS cartridge in a J rifle (.318 bore). In a quality bolt gun with the proper bore 50,000 to 52,000 cup is qute acceptable. in fact most reloading manual data produces pressure in that range for the 8x57 loads.

If I limit the pressure to a maximum of 52,000 cup (equal to the 308), and with the increased case capacity over the 308, I think I may be able to match the 30-06 and Maybe even get a few fps more. Of course until I actually make a few rounds and a gun to shoot them in I won't know.

[Good Cheer]

Basic steps:
(1) Figure out the diameter and weight of bullet needed to do the job.
(2) Figure out the firearm you want to do the job with.
(3) Take the cartridge case that will work in the firearm and put a neck on it long enough to accomodate the lube grooves on your bullet.
(4) Adjust the brass length to fit the over all cartridge length to fit the chosen firearm.
(5) What's left over is powder space.
(6) Get the chamber reamer and loading dies made.
(7) Yeehah!

[Bullshop]

Yes you are right you can exceed the velocity of the 06 case with the 57mm case but as I said at higher pressure.
I dont really understand what your up to. You did say to keep it in a smaller package but the 57mm case will require the same action length as the 06.
If you really are out to equal or exceed the 06 performance at equal pressure you would need to go with a case like the 350 mag or 284 or something similar that was designed for short action but having 06 case volume.
If all you want is higher velocity then just kick up the pressure of the 06 to that of the 308 or a 300 mag as long as you have an action that will handle it.

[rtracy2001]

Yes you are right you can exceed the velocity of the 06 case with the 57mm case but as I said at higher pressure.
I dont really understand what your up to. You did say to keep it in a smaller package but the 57mm case will require the same action length as the 06.
If you really are out to equal or exceed the 06 performance at equal pressure you would need to go with a case like the 350 mag or 284 or something similar that was designed for short action but having 06 case volume.
If all you want is higher velocity then just kick up the pressure of the 06 to that of the 308 or a 300 mag as long as you have an action that will handle it.

I seem to have two dissabilities.

First I like things that are out of the main stream.

Second, I've been looking at the 8x57 data and the 7x57 data, it looks like the 57mm case might just be a more efficient design than the '06. I would like to find out on equal footing.

Maybe it is all just a pipe dream...

[Bent Ramrod]

Get copies of Richard W. Simmons' Wildcat Cartridges, P. O. Ackley's Handbook for Shooters and Reloaders and Ken Howell's Designing and Forming Custom Cartridges. George Nonte's book Cartridge Conversions does not cover wildcatting so much as the techniques for reforming cartridge cases into obsolete ones, which would serve the wildcatter as well.

If you can find any unexplored ballistic territory after going over these tomes, my hat is off to you!

[Bullshop]

Anytime you reduce capacity you gain efficiency. The same relationship is there between the 308 case and the 57mm case as is in the 57mm verses the 06..
If you could fire a 30/30 to equal pressure you would see greater efficiency over the 308.Look at how efficient the 30/30 AI is even at only 40,000 psi, or even smaller like the 300 whisper or 30BR.

[Trifocals]

As was suggested in several of the previous posts, obtain the books pertaining to what you want to do. There is a very good chance that something similar to your idea has already been done. Further, there is quite possibly a factory cartridge that accomplishes what you might be attempting to achieve. P.O. Ackley covered a whole lot of ground with his ideas and a review of his and other "wildcatters" developments is quite enlightening indeed. Generally speaking, the goal of a wildcat cartridge is a velocity increase. Other times it may be to modify a shoulder angle to eliminate case stretching. For those that are trying to wring out the maximum possible fps of velocity, I always ask "why"? If it is to increase a bullets range to "way out there", is the shooter capable of making those very long range shots? Do they possess the skills to repeatedly kill a quarry at very long range? Very few do, so the extra velocity is essentially wasted. The critter will surely expire (if the shot placement is correct) if hit by a standard factory round with a muzzle velocity of 2750 fps or some super double whammydammit wildcat based on the same case with a muzzle velocity of 2800 fps. Many times wildcats end up with a voracious appetite for powder and they become overbore with the result that a point is reached where the increase in powder capacity produces a very insignificant velocity gain. Many have tried to re-invent the wheel so to speak, with very mediocre results. True, there are some signifigant wildcats that have evolved to factory cartridges, but it is a stretch to hope that happens often. The ammo and firearms manufacturers regularly play a little game with consumers. They change the shape or caliber of an existing cartridge or design a completely new cartridge and hype it as so great that we should absolutely have firearms chambered for it. Naturally the firearms manufacturers come out with new guns chambered for the new cartridge. Next a bunch of "experts" who author articles for the gun rags use the cartridge on some safari or hunting trip that the majority of us average people could not afford and pronounce that it is a wonder to behold. The consumers take the bait and buy. The problems with this is that consumers soon discover that the new cartridge is not all that much better than one of the old reliables that have been with us for many years, so sales drop and the cartridge is discontinued by the manufacturer. Try going into a little country store to buy fodder for your fairly new rifle chambered for one of the newer whiz bang cartridges. You will find they probably have never heard of it, but have plenty of ammo for the old standbys such as .30-30, .308, .30-06, .270, .243, etc.. I am reminded of a gentlemen I knew about 25 years ago. He was ecstatic that he had developed a vastly superior .270 wildcat based on the standard .270 case and spent many hundreds of dollars on reamers, custom dies and gunsmith fees. He even tacked his name on the wildcat cartridge. When he proudly showed me the culmination of his idea, I promptly showed him in the book of wildcat cartridges that his "baby" was an almost identical copy of one of Rocky Gibbs wildcats. It certainly deflated his ego in a hurry. Do yourself and your wallet a huge favor before you dive into the deep end of developing a wildcat. Do your homework first. LOL

[1Shirt]

Guess I am just old school! As far as I am concerned, the last real practical wildcat was the 22-250, and when Rem. made it factory, to me that was proof. The cost of wildcat development in my opinion would more than pay for a number of very good, standard cals, in very high quality weapons. For those who have the time, the equipment, and the money to screw around with cartridge modification today, more power to them. I have in the last 50 plus years, seen a number of ctgs. come and go, and some hang on, and some like the 45-70 even have a rebirth so to speak. I have one wildcat, a K-Hornet, and love it! However, the development of that wildcat occured when I was a teenager. Think that like a lot of mines, for me wildcatting has about played out the return for the effort. I guess however that as long as there are gunwriters, gunsmiths, gun enthusiasts, etc.etc.etc. there will always be the quest for the better wildcat, the extra 100 fps, and the ability to name the next wizbang wildcat after someone or some thing. It is kind of like the quest for the premium blt. Find it kind of hard to believe that there will be something much better than what is on the market now (if you can afford them) but who knows what the next few years will bring?
1Shirt!

[Bullshop]

I didnt want to spill the beans before it was ready but I have been working on a new wildcat that I am sure will be far more efficient than all other in its class.
Keep it under your hats because I dont want anyone stealing my idea, OK.
Its a 375 hornet. It does require some alteration to the bolt face but it is an extremely efficient cartridge.

[1Shirt]

Bullshop, If ya get that one worked out, might be interested in it providing vols are in the 2000 fps range.
1Shirt!

[Bullshop]

1shirt
At allowable pressure you may have to go to the K (IMP) version, unless you use some of the 375 to 17 sabots we are developing especially for this cartridge.

[1Shirt]

Bullshop, Most interesting! Look forward to your future development of the sabots! Please advise as development progresses.
1Shirt!