One of the most deadliest rifle calibers on earth, you will never guess

[Frohickey]

One could also make his own jacketed bullets with the use of swaging dies. An outfit by the name of Corbin use to and maybe still does sell bullet swaging dies in any weight and configuration that you might want.

Dave Corbin still makes bullet swaging dies.

In fact, you can make 22 caliber bullets out of a RCBS Rockchucker, using fired 22LR cases as the bullet jacket, and lead cores as the inside material. Unfortunately, this only makes a 55grain bullet, if you want the jacket to cover everything. If not, you can go as long as you want, or you can buy longer jackets.

His only caveat about 22LR jacketed bullets... you need to drive them a bit slower because the thin jackets then to shed from the lead when you drive them too fast. Plus, on soft skinned target, they will shed their jackets, often into itty-bitty pieces as the bullet encounters a sudden change in spin. Pink mist.

 

[bernie]

It is my understanding that the military went with the 1 in 7 twist not because of the M855 bullet, but the M856 which is the tracer version. I have handloaded with M856's and they are LONG. They are a wooly booger to get stable, and when you couple a tough to stabilize bullet with extremely cold environments, stabilization becomes a major problem. That is why you really do not see much difference between a 1 in 9 Bushmaster AR and a 1 in 7 M16A2. I could be wrong, but this is what I have been led to believe.

 

[Dave R]

As I think this through, I think the penetration comes from its velocity and small sectional density.

Here's some bait--someone give me a breif explanation of the difference between energy and momentum. I "think"

Energy=mass X velocity squared.

Momentum= mass X velocity

Notive the former with the squared velocity. That would "reward" velocity a bunch more than mass.

 

[JShirley]

What Bernie said. The M856 is...drat, can't find it right now, but I think it's about 1.2" long. M855, for comparison, is only 23.30 mm (0.917 in) long. As we know, it's the bullet length that calls for a faster twist...

 

[Art Eatman]

Dave R: One way to look at Kinetic Energy is as a measure of "explosiveness". For a rifle bullet, a thin-jacket hollow-point releases its energy inside the target, and that energy is what creates mush. (A bullet which exits a target didn't release all its energy inside...)

Momentum is a measure of an object's propensity to keep on truckin', against some force imposed upon it to give a negative acceleration. Consider the comparison of a bowling ball and a golf ball rolled along a smooth surface, and which is harder to stop.

There's a lot more to it, of course, but who needs a bunch of Physics course and a blackboard? If I didn't have a blackboard to draw pitchers on, I'd wind up needin' a physic.

Anyway, a Swift kills mostly from having its energy released inside an animal, destroying a lot of tissue. The original .45-70 kills by large-hole penetration through a long distance within an animal, commonly letting it bleed out. The medium-diameter hunting bullets represent an effort to combine speed for KE, and heavier bullets with slow expansion and toughness to maintain momentum for lengthy penetration.

Art

 

[gk1]

P.O. Ackley used a solid copper bullet with a hollow tip (or was it a lead tip?) to take those 600-lb. donkeys or burros or whatever. I'm not sure if he was using the copper bullets in the penetration tests or not. It's been years since I've read that book, but it is one of the best ever.

Someone asked (jokingly) about penetrating an Abrams; actually the saboted round fired from the Abrams does about 5200 fps (really fast, anyway), and does vaporize the armor on the way in.

George

 

[Jim K]

Much of the secret of the Swift's velocity was simple - a 45 grain bullet. With that weight bullet, and the right loads, the .22-250 will do the same as the Swift and more. The Swift bullets are also pretty thin jacketed and have been known to blow apart in mid air due to the centrifugal force resulting from the combination of a high rotational rate and that thin jacket. I once tried an experiment using Swift bullets in a .22-250 loaded to an estimated 4200 fps. Half of them never reached the target. You could see the puff of "smoke" as they blew apart in the air.

As to penetration in steel, non-AP bullets penetrate, as noted, simply by melting the steel. When a fast moving bullet strikes a solid object, the kinetic energy of the bullet does not simply go away (law of conservation of energy), it is instantly converted into heat. That heat will evaporate the bullet itself (fire .22 LR at a rock and observe the droplets of lead) and, on a steel target, also melt the steel. The problem is that that type of penetration leaves little or nothing to actually go through the steel. It's fun, but the military wants a bullet that will kill the people behind the steel. So they settled for a compromise AP bullet that won't actually penetrate as deeply, but which has a carbide core that will go through the steel to do damage beyond it.

Jim

 

[Meanoldfart]

Men, this got way too serious for someone who was just trying to make a pile of link sausage.

 

[Dave Markowitz]

The reason for changing the M16 twist rate from 1-12 to 1-7 is to stabilize the heavier bullet.

More specifically, the US military went with the 1:7 twist to stabilize the very long for caliber M856 tracer bullet, not to increase penetration.

 

[Lone Star]

All I know is that bullets which have "fast" rifling twists, like the various 6.5mm's and the 7X57mm do have a reputation for being unusually effective in view of their bullet weights and velocities. And, I've seen tests that pitted Colt .357's (1-14 twist) against S&W .357's (1-18.75" twist) and the Colts expanded bullets better at very similar velocities. This even held true when comparing the two firms' snub .38's.

But I know that Robert Ruark took a .220 Swift to Africa, and commented negatively on it in, "Horn of the Hunter" after trying to kill a hyena with it. His white hunter encouraged him to use more traditional calibers for the game being shot.

Lone Star

 

[MP-44]

Robert Ruark used the 220 in Africa on a hyena with not so good results. Swore he would never use it again.

 

[Art Eatman]

Ruark's problem with the Swift occurred in the same time-frame as my comment about the bullet technology of the 1950s...In that era, folks who tried the Swift on deer often had bullets blow up near the surface of the animal--say, on a rib--and got little to no penetration. Crippled deer with open wound; in Texas, that often meant escaping to later die from screw-worms eating him alive.

If you look at bullets for reloaders, there are two types of .224 bullets: Those meant for the high-speed critters like the .223 and faster; and those meant for the low-speed jobberdos like the Hornet.

A Hornet bullet out of a Swift will vaporize in flight; a Swift bullet out of a Hornet won't expand very much.

Ancient story: Proper tool for a proper job.

, Art