Rem700 wrote:Seismic Sam the graph you posted is of Black Powder would smokeless show the same results?
Thank you Rem700, while I hard read the word "goex" I had failed to associate it with black powder. You don't normally see any black powder data in smokeless powder handbooks.
As it turns out, black powder is actually a SIMPLIFIED case of the situation with smokeless powder, because black powder only has ONE burning rate. (about 1,000 FPS, if I recall...) It goes bang at a certain number of feet per second whether it is in the can, in the rifle, or lying in a pile on the ground. That's what makes it so dangerous when you have a 1 lb. can of black powder, because it is equal to either 2 or 4 sticks of dynamite. The nice thing about black powder is that it only has that one burning rate, and you can't do stupid reloading stuff to double, triple, or make the stuff outright detonate like smokeless powder. While adding more powder to the gun does make the pressure go up, it does NOT change the burning rate. that's why you could have the 45-70, 45-90, and 45-120 round all work in similar guns. There is no way in hell any smokeless powder load could have a safe span from 70 to 120 grains.
So, let's talk smokeless powder burning rate. It is VARIABLE, and proportional to the pressure it sees while it is burning. You can pour some on the ground and light it, and it will burn and fizzle about like solid gasoline (if that fast) and that's about it. Put it in a rifle or pistol case, and the effects are entirely different. As an example, consider one of the few stupid things I did while I was in college (as opposed to 1911fan, who did ALL of them!!) with some Bullseye pistol powder. (Yes, I was handloading with a $7.56 Lee handloading kit in the dorm. This was NOT the unsafe part!) I was using Bullseye pistol powder, and had previously burned some on the ground, and watched it go POOF!! like when the magician disappears. So we were screwing around on Saturday night in the dorm, and I go upstairs and pour maybe 30 grains of Bullseye into a plain paper envelope, lick it and seal it up, and I take it back to the louge to put under somebody's chair and make it go POOF!!! Well, I lit the corner of the envelope, and the damn thing went BOOM in my face and burned the hair off a guy's leg. Turns out a paper envelope has enough pressure containment in it to actually make Bullseye go boom!!
Now then: To the guy with the Mauser and the KABOOM - The primer initially fired and ignited some of the powder and boosted the pressure of the rest of the powder, the bullet stuck in the barrel, and then the main load burned, and with the initial bump in pressure and the stuck bullet, the load actually detonated. Detonation means that the force wave goes through the whole charge in microseconds, and has a burning rate like primacord or det cord, which is on the order of 5,000 - 10,000 feet per second. Yeah, 10,000 FPS, and the bullet from a 204 Ruger ONLY goes 4,000 FPS!! That's how freaking fast detonation is, and why the rifle blew completely apart.
There are other ways to detonate powder. The most infamous one is reduced charge 44/357 Mag loads using 296/H110 powder. 296 is slow burning and MUST have a magnum primer to work, and if you use a regular primer you will have a REALLY dirty gun and noises that sound like HammAR's beer farts after an Alary's night. So: The proper magnum 296 load means the case is almost full, and things work quite good. Reduce the load so that the case is maybe 1/2 empty, and you could have a detonation. Which scenario hasn't been proven, but the magnum primer either ignites the whole surface of the powder to create a fast burn and pressure spike, or the primer throws (sort of atomizes) the powder throughout the case and then the whole charge burns in an instant. Either way, you generally wind up with your 44 mag revolver in pieces and God only knows about your hands and face.
Which brings us to another fact newbies are ignorant of: The friction between the barrel and the bullet is one of the variables that control smokeless powder burning rate. A jacketed bullet has more friction and will therefore generate higher pressures and velocities than a cast bullet. Barnes solids (100% bronze metal, no lead) will generate higher pressures than equivalent weight lead bullets with copper jackets. So, if you develop a nice 44 mag load with cast bullets and then switch to the hottest load you had with jacketed bullets, you have phucked up big time!! That is why when you change ANY component in a load, you have to work it all the way up again from the beginning.
And back to the 40 S&W load: the 40 S&W is fairly infamous among handloaders for being intolerant of mistakes. Problem #1 is that tupperware guns do not fully support the bottom of the case, so the potential for a case blowout is maximized. Problem #2 is that the max load for the 40 S&W is only 1,000 fps with a 180 bullet, so the case is not overly strong. Problem #3 is that if your case mouth crimp isn't good, the bullet can set back into the case upon feeding, thus jacking the pressure with a weak case and an unsupported case wall, and KABLOOEY!! (and who here knows how to and actually DOES mike their case mouths before and after applying the taper crimp, so you know how many mils of crimp you have??) Oooohhhhhhh.... look at all those blank faces out there!!
That's just a small fraction of all the stuff you need to know to be a safe handloader, and on an ignorance scale of 1 to 10, swapping magnum primers for regular primers with the same powder load rates a good, solid 8, and that's for "safe" calibers like the 9mm and 45 ACP, where it's harder to screw up.
