Re: 5000 meters+ Supersonic
I preface the following comments by stating exactly what I told Jon at Shot; As the "most powerful shoulder fired weapon in the world", this project can be characterized in a single word... "idiotic". As a potentially useful mounted cannon, he might interest someone in the cartridge for military applications... provided he gets a barrel with a twist rate of at least twenty calibers, and preferably tighter. I also suggested that he initiate a new thread that aknowledges the patent BS, and get serious about the opportunity to learn something from his efforts irrespective of commercial considerations.
I see that he is back to hawking this project as a sporting rifle available to all persuant to an ATF "exemption". I have read the so-called exemption. It is, in fact, a *clarification* permitting him to manufacture this gun provided he does not cross over into the military application with his cartridge. Does this raise any red flags?
I know some of you read this thread for entertainment value, and to you I apologize for a slight diversion. My comments are directed to those who believe the representations made by the crew responsible for this thread are *factual*. Without dissecting the entire presentation, focus on the post by ELR researcher:
- Q3: What have your field tests yielded?
A3: Muzzle velocities in the range of 3,300 to 3,500 fps.
The real answer is that Jon has never field tested this rifle. An earlier version was taken out without his prior knowledge, and absent verifiable controls.
- Q4: What is the comparative case capacity between your brass, and the Vulcan?
A4: 14 more grains water capacity in my case.
I am going by the photograph. The 14.9 mm case body appears to be ~80% that of the Vulcan in length. Eliminating the 1.7mm taper in this section yields a 32.5 cc volume. An unmodified Vulcan has a body volume of 39.5 cc. Assuming that projectiles are seated at the neck/shoulder junction, and that the two shoulder volumes are roughly equal, then the Vulcan has a 7 cc volume advantage. One cubic centimeter equals 15.4 grains water... do the math.
- Q5: How is high density loading achieved through the use of blended propellants?
A4: Vibratory consolidation within case.
Real answer, yes it is possible. Jon does not know yet because he has not field tested his loads. Two factors which are likely to work against him are properly graduated, and quantified, particle size, plus dissimilar propellant specific gravity. Poorly graduated sizes will settle the smaller granules to the bottom, as will higher density particles. Nitrocellulose alone varies by as much as 10%, and double base propellant ranges between 4% to 40% nitroglycerin.
By all means, enjoy the thread. Something good can come of this, but question *everything*. There is meager committment to accuracy.