Over the last forty years I have watched and read hundreds of attempts to conceive new cartridges. There has been a parade of shapes and designs marching through the publications. A few were sensible, a few exotic, and a great many were just plain weird. Each one was supposed to do wonders! A few even made it to the factory, for better or for worse. Many of these fell by the wayside when shooters realized that they were more smoke than meat. Strange as it may seem, some of the best, like the 6.5-06, never made it, while oddities like the 6.5 Remington Magnum came and went. Others like the .300 Winchester Magnum, with its bullet pushed down into the powder capacity, live on, while the wildcat .30-338 still lingers in the back. Both have the same usable powder capacity, but the .300 Win. Magnun just looks more powerful! There you have it: it must look like it's big and robust to satisfy the public. I will discuss this later, but for now let's move on. So, what is a Wildcat? It's a design, good or bad, that is not offered by the industry.
The Two Concepts Behind The Design Of Wildcats
The two concepts behind the development of a wildcat design are the same motives the shooters have when they buy a factory round. On one side of the scale we have the Hyper-Velocity shooter, who want maximum velocity with relatively light bullets. This does not mean he's a long yardage shooter in all cases. He believes in the Hydro-Shock theory, that a bullet traveling at Hyper-Velocity transmits shock waves to nerve centers and causes water, that cannot be compressed, to become a secondary moving missile. In other words, the mass of the bullet and its velocity transfer all their K Energy into the target, thus killing it with major tissue damage and nerve shock. On the other side of the scale, we have the shooter that believes in the Mass and Momentum. He is not looking for Nerve Shock, but rather a deep and large wound channel that causes quick bleed down. This quick bleed down starves the brain of blood by quickly reducing the blood pressure. The larger the internal area of the wound channel, the quicker the bleed down and death. The scale seems to be balanced around .35 caliber, with some overlapping. It is not the object of this article to favor either side of this argument, but to bring into focus what the designer of a wildcat cartridge is aiming at.
The Evolution Of Wildcat Cartridges
The end of World War II saw the development of the wildcat cartridge move into the fast lane. Every gun writer felt honor bound to show the public that he was an expert in the field by coming up with a cartridge that bypassed anyone else. This resulted in volumes of wildcats, most duplicating each other, with wild claims that could not be reproduced under controlled situations. However, there was a handful of professionals that did come up with sound ideas. The foremost was Parker Ackley, with his "Improved" cartridge line. Many think he was after more case volume, aimed at burning more powder. That is not the complete case, although an important factor. He was the first to realize that reducing the angle of the sidewalls of the case reduced bolt thrust and that making the angles of the shoulder steep enough caused the ultra high temperature gas and powder particles to intersect inside of the case and not in the leades. These factors were just as important as the additional powder capacity, and show up on all of his "Improved" versions. Frank Barnes went another direction. He conceived early what we now call "High Efficiency Case Designs" with some like the .308-1 1/2" Barnes. He also went over into the big bores and started developing very efficient cartridges for big game in this country. Ackley and Barnes realized that one could only increase powder capacity to a point of diminishing returns. You can only add so much powder until the pressure goes out the top, with very little gain in velocity. This fact ties the Ackley and Barnes theories together. Both understood the importance of the Expansion Ratio of a barrel relating to efficiency of the powder burn to velocity and wear on the barrel. Expansion Ratio is the number of times the gas in the cartridge case volume can expand in the volume of the bore. The higher the Expansion Ratio the more efficiently the powder burns. I will mention that most of the Hyper-Velocity cartridges do not have high ER barrels, but the shooter pays for it with wear, throat erosion, etc. We now come to the one man who helped wildcat designers more than anyone.The late Homer Powley was a sincere and modest genius. He understood CWR's and ER's. He was the first to prove that cartridge shape had little to with the ballistics of a cartridge. His "Powley's Computer For Handloaders" is used more by advanced handloaders and cartridge designers than any other tool. With his advanced knowledge of powder characteristics, especially the IMR's, he build a method that take the guesswork out of cartridge design. The amazing thing about this tool is that it calculates velocity and pressures of IMR powders within 5%, and that 5% is based on the variables between different barrels, etc. There was some question as to why the tool takes .859 of the cartridge case's water capacity and coverts to the amount of powder. Many so-called experts claimed this was a "Safety Factor"; however, I knew that the relationship of the density of powder to water ranged about 85%. I talked to Homer shortly before his passing and he confirmed my idea that his .859 was a conversion factor from water weight to powder weight for IMR powders. When one looks at Ackley's books on wildcats we see a vast number of designs, shapes, and some oddballs. If they duplicate powder volume and bullet weight, they duplicate ballistics - Period! Some claim today that a short, fat powder column is better than a long, thin column. If so, it's hard to prove. I am inclined to believe that if equal care is taken in the case's manufacture, primer hole uniformity, trim, ream, and all other things that match shooters do, and the same case volume, powder volume, and quality of bullet is used, accuracy will be the same. If you don't think that, then prove your case. Ackley tried it, using different cases and the same barrel; resulting accuracy was the same. I did the same with a .25-06 and a .257 Improved Krag one time, switching barrels, and got the same groups with the same bullets.
So, here we go again....What does the shooter of the 2000's appear to want? First of all: Power and/or Speed! That's a fickle desire, since each of these, or a combination of them, develops weight and recoil beyond the ability of most shooters. We have on one side of the scale ridiculous velocity and on the other over-penetration. It is not my intention to ruffle feathers, but facts are facts! There are experienced shooters today that handle recoil and weight well above average, and my hat is off to them. They are the exception, not the rule. The reason I have said this is because it is important in developing a wildcat cartridge to keep all of this in mind! It must have universal appeal to a wide range of shooters or answer the needs of a select money group.
Requirements of an Efficient Wildcat Cartridge
First and foremost, it must be made on a existing and easy-to-acquire parent case. It must fit popular actions that are available. The heydays of cheap Mausers and Springfeilds are gone, so the best source are rifles with burnt barrels, etc; that way you can salvage everything but the barrel. In rare cases it will work by rechambering or setting back the barrels on existing rifles, since barrel cost and work goes up daily, as do reamers and dies. There are other considerations to remember: high velocity means low ER and longer barrels, where lower velocity with higher bullet weight means higher ER and shorter barrels. Another important consideration is whether you want to shoot jacketed or hard cast lead bullets, or both. Hard cast bullets call for a high ER for best results. Usually, high ER's call for the medium burn rate powders; this goes cross-grain with some shooters wanting to burn slow powder with hard cast bullets. I have found that medium burn powders do work with hard cast bullets with gas checks and high ER barrels. However, if you have a high case capacity, like .30-06, by all means use a slow burn powder to fill up the case near 100%. Most of the problems of the past were traced to lube failure, not the powder. Wonder Wads help in .35 caliber and up with hard cast bullets. These wads compress to nothing and help seal, sweep, and dry lube the bore. For our choice of utility repeating guns that will shoot hard cast and jacketed bullets, let's pick a Marlin action based the .45-70 cartridge as our test platform. These are strong actions that will work in the range of 41,000/43,000 psi. I have found that they will feed both rimmed and belted cartridges up to the length of .45-70 (or 2.47") with only minor fitting. This was verified by Marshall Stanton. Let's now discuss the .416 x 2" Beartooth, how it was designed, and what it will do.
The .416 x 2" Beartooth
I am not the first to think .416" bullets are a natural when combined with the 2" case. O.A. "Tony" Winters worked up an outstanding wildcat some years ago, called 10.6 x 51 mm. For all practical purposes, the .416 x 2" Beartooth is the same ballisticlly, with jacketed bullets. Winter's load data with jacketed bullets can be used in the .416 x 2" Beartooth with no problems. So why not just use Tony's layout? Good as his is, it has one short-coming when dealing with hard cast bullets, and that is a too short neck (.370"). The neck length is very important with hard cast bullets, due to the fact we do not want the bullet and lube grooves pushed down and exposed to the burning powder. With this in mind, I selected Beartooth 375 gr. .416 bullet. The distance from the crimp groove to the base of the bullet is .620". I pushed the shoulder back this distance, making the neck length .620" while losing little powder capacity. The overall length of the loaded round then is 2.470" and right up to the maximum the Ruger will feed. We now have a case with a powder capacity of 50/52 grs of any powder with a Load Density of .859, the average of IMR powders. Ball powders have a much higher Load Density: for example, H335 @ 1.0051. This means you could put as much as 55 grs of H335 in the case; however, this is not a recommended load. Now that we have covered feeding requirements and powder capacity, let's move on to barrel length. With a 20"/22" barrel the Expansion Ratio would be as high as 12. This is an excellent level for an efficient powder burn, long barrel life, and lower pressure at the muzzle. With the factors so far, I turned to Powley's Computer For Handloaders. By taking the 60 grs water capacity x .859 (average LD of IMR's) we get 51.54 grs of powder. Dividing this by the bullet weight of 335 grs (to get the highest velocity), we get a CWR of .1539. By running this through, CWR@.1539 and ER@12, we get a readout of 2060 fps. Now people, that works out to some 3157.37 pounds of energy at the muzzle! By running the data through the Powley PSI Calculator, we come in at 37,000 psi. Hornady says that the .450 Marlin works at pressures of 42,000 to 42,500 psi. Now is the time to let the computer tell us what the ideal type of powder (of 51-54 grs) with a 335 Beartooth bullet (SD@.2767) is, and the answer is right on the line for IMR 3031. This has always been an excellent powder for this type of round and opens up all kinds of possibilities with H322 and H 335! Conclusion
Warning! If you call me an "Arm Chair Ballistics Egghead", I will bite back. All of these calculations you can do yourself! I highly recommend that you learn to work with the Powley, if for no other reason than to give you a method to check outlandish claims by the "pulp paper pushers"! With your actual field experience and the Powley, there is absolutely no reason that you can not develop a wildcat aimed at your criteria.
After completing the above work, I realized that I had overlooked one other wildcat cartridge that was based on nearly a 2" case. I refer to Frank Barnes's last wildcat, the .416 Barnes. Although the case was made on a cut back .45-70 (2.112"), the capacity was very close to the .416 x 2" Beartooth.
Interestingly enough, we find that he got a velocity of 2045 '/" (ME @ 3065 fps) with a 330 gr. cast bullet using 50 grs. of IMR 3031. This verifies my calculation within 1.54 grs of IMR 3031! The .416 Barnes was, and is, a great cartridge for North American game. However, like Winter's cartridge, it has some drawbacks: made on the .45-70 case, it is not best suited for bolt guns. Also, it's OAL is 2.950", too long for the Marlin.
As one final test, I took a WW 7mm Rem. Mag. case and cut it to precisely 1.380". This is the distance to the base to the shoulder of the .416 x 2" Beartooth . The following are actual weighed powder charges: RE7 @ 49 grs.- RE12 @ 50 grs.- RE19 @ 48 grs.- IMR 4198 @ 44 grs.- IMR 3031 @ 50 grs.- IMR 4064 @ 48.5 grs.- IMR 4350 @ 48 grs- and Hodg. Ball C2 @ 54 grs. So, I missed my calculations by 1.54 grs of IMR 3031. These charges were not compacted, and may run a grain or more if vibrated in. I know of no other way to verify my calculations, and unless someone out there wishes to challenge my figures, I plan to accept them.