Man, I must have really hit a sore spot or something.....
"only twist will cause a bullet the come apart in the air. give me a 1/6 twist 223 and I could pretty much make any bullet come apart at less than 3000 fps."
Wrong. I had a box of Federal Premium .243 with 100 grain Sierra Gamekings that were several years old. I was shooting them at 50 yards to get on target and all that was hitting the paper was shreds of copper and lead. Sent the rest of the box to Federal,and they sent me a new box, stating that the bullets in the box I sent them were disintegrating before they hit the target, and they had no idea why. They ended up recalling that entire lot of ammo. Must have been a manufacturing issue, but it shows that it does and can happen. That was about 10 yrs ago.
"Please tell me which aircraft? Unless you are talking about the shuttle, there are none. Show me differently, I'm all ears."
Here's a paragraph about the development and design of the Lockheed SR-71 Blackbird:
Lockheed's first proposal for a new high speed, high altitude, reconnaissance aircraft, to be capable of avoiding interceptors and missiles, centered on a design propelled by liquid hydrogen. This proved to be impracticable because of considerable fuel consumption. Lockheed then reconfigured the design for conventional fuels. This was feasible and the Central Intelligence Agency (CIA), already flying the Lockheed U-2, issued a production contract for an aircraft designated the A-12. Lockheed's clandestine 'Skunk Works' division (headed by the gifted design engineer Clarence L. "Kelly" Johnson) designed the A-12 to cruise at Mach 3.2 and fly well above 18,288 m (60,000 feet).
To meet these challenging requirements, Lockheed engineers overcame many daunting technical challenges. Flying more than three times the speed of sound generates 316° C (600° F) temperatures on external aircraft surfaces, which are enough to melt conventional aluminum airframes. The design team chose to make the jet's external skin of titanium alloy to which shielded the internal aluminum airframe. Two conventional, but very powerful, afterburning turbine engines propelled this remarkable aircraft. These power plants had to operate across a huge speed envelope in flight, from a takeoff speed of 334 kph (207 mph) to more than 3,540 kph (2,200 mph). To prevent supersonic shock waves from moving inside the engine intake causing flameouts, Johnson's team had to design a complex air intake and bypass system for the engines.
If I calculated it right (always subject to error,
), a bullet that's going 2200 fps is moving at approx. 1500 mph. Yes, air resistance will generate some heat, and taking into account that the bullet is continually slowing down, most bullets are just fine. But not all of them. In theory, a soft lead bullet could deform just from the heat of the air resistance. The melting point of lead is lower than aluminum.
About what I read about lead bullets at 2100-2200 fps, I can't find the article anywhere. I think that I read it on (god help me, I apologize already) on Wakeman's website. As for the rest of it, if you take away the heat from powder, pressure, etc, you are shooting a 22-250 caliber air rifle?? I admit that the jacketed handgun bullet thing does sound pretty dumb after re-reading it. What was I thinking of.....
You bring up the .308 100 grain plinker.....a bullet designed for those velocity's that are generated. Designed is the key word. They know that the bullet will hit 2300-2400 or whatever FPS, and designed the lead tip/core to withstand those speeds. The jacket also helps to keep everything together as it passes through the air. Remember, this discussion about bullet performance started with
soft lead bullets that aren't really designed for speeds over 2000 fps. You can take a bullet, cast it out of wheel weight alloy and push it pretty damn fast and not worry about it. It's a hard lead bullet. Not a softer one for lower velocities.
All of this is pretty much a pointless debate really. I fully admit (and I think that the rest of us do too) that it's a bunch of "might happen", "could of", "what if" etc. There are so many variables involved that you can't control, that's why ballistics is a trial and error science. In theory, you can push a soft lead bullet as fast as you want, and not have one problem. That's great. That's the way we want it to be. Sometimes it works, sometimes it doesn't.
