What is the highest FPS recorded?

[t45]

Just wondering what the highest FPS that has been recorded by a conventional rifle/ammo combination. I know some of the 17's go 4200-4300fps. I have been able to push my 22-250 to around 4100fps. Im sure someone has gone faster.

[mehavey]

...able to push my 22-250 to around 4100fps. Im sure someone has gone faster.

Ditto here on the Swift (but I think you have that 22-250 playing over it's head)


I have seen (pics of the chrono) for a 22-243 hitting a mile-a-second though.
See here for more on those kind of you-gotta-be-kidding load-outs:
http://www.predatormastersforums.com...Number=1480157

You and I are pikers by comparison.

[Kiwi Hunter]

One of our local nutters got 5200+ out of his 22.243 - he also got exactly 3 shots at that velocity (primers nowhere to be found apparently)

He posted a pic of his barrel sectioned and it looked like someone had been up there with a welder

He posts under the name Crazy-man

[chris in va]

Holy crap, that's Mach 4.72! I don't think SAM's even go that fast.

[Scorch]

About 5,400 fps, IIRC. Pretty hard to get there, though, pretty much gun research lab stuff. In the real world, there are some supervelocity 22 cal centerfire rounds that will launch a 55 gr approaching 4,300 fps (22 Newton, 22 TTH, 22 Middlestead, 22 CHeetah, etc), 20 cal centerfires that will launch a bullet at close to 4,300 fps, and 17 cals that launch at 4,300 fps. 5,000 fps is the Holy Grail of gun designers, if you can get there your 15 minutes of fame is assured.

[Win_94]

He posts under the name Crazy-man

The chronograph is taken apart. The eyes could have been set at half the distance, while getting that reading with a 30-06.

Oops, my mistake, that is a different chrony than mine.

[misskimo]

I 7400 a few times. But. I had my crony right at the end of my barrel. False reading

Rand those are fast

[Brian Pfleuger]

I load Win748 under Nosler 35gr BTs in 22-250. They chrony (at 15 feet) at 4,435 fps from a 24" Rem700 and it is not a max load. It's the best load I've ever seen for woodchucks. Point blank range is just about 330 yards, sighted 1 1/2 high at 100.

I plan to get a 28" 22-250 barrel for my Encore. I should be able to easily exceed 4,600 and probably 4,700 fps at max load.

Originally Posted by Scorch

5,000 fps is the Holy Grail of gun designers, if you can get there your 15 minutes of fame is assured.

How long can my barrel be?

[jtmckinney]

ABC's Of Reloading Eighth Edition Edited By Bill Chevalier covers this in chapter 3 "Understanding Pressure And Headspace".

On Page 32:
"This velocity ceiling is in the range of 11,000 feet per second (fps), and has been achieved with a steel ball blown out of a smooth bore-hardly practical."

"A little over 4,000 fps is the maximum practical velocity that can be expected to produce a reasonable barrel life-a span of a thousand shots at the very least before accuracy degrades to a marked degree"

Sounds you are at the practical limit per this publication.

Sounds like fun.
James

[Brian Pfleuger]

Pressure and heat have a much larger effect on barrel life than does velocity. If I can achieve 4,400, or 4,700, with the same pressure (and thereby same approximate temperature) as would produce 4,000 or 3,800 with a heavier bullet then barrel life should not be substantially effected.

Besides, that sentence completely ignores barrel length. If I can get 4,000fps with one barrel and load combination and I put that same load in a barrel that's 8 inches longer and get 4,400 fps, why would that effect barrel life?

Plus, when was that written? How would that sentence be effected by advances in barrel metallurgy, powder and bullet technology?

[brickeyee]

The issue comes down to powder 'design' and the need to create a higher average pressure while keeping peak pressures under control.

Very slow powders and long barrels will get you there since the average pressure remains high for longer.

Large guns with shrunk on outer jackets to pre-compress the barrel (especially in areas the pressure will be higher) can get to very high pressures, and the large grains of powder used can be altered in shape (holes of different profiles, etc.) to allow for higher average pressure while still controlling peak pressure.

One of the limits that comes up is that no projectile can exceed the speed of sound in the driving gasses (if it did there would be Mach waves and the gas would no longer 'keep up' with the moving projectile).

Barrel life is going to be a problem though as the pressures and temperature increase to drive up the speed of sound in the driving gasses.

The fastest guns (outside of electromagnetic ones) are the gas guns.

Think of them as a gigantic spring piston air gun.
Explosives are used to drive a large slug that then compresses a very light gas in a piston.
The piston chamber has a very small exit at the other end.
The gas then drives a projectile.

The change in diameter from the large piston to the small projectile is similar to using a sabot to fire a smaller diameter projectile in a larger diameter bore.

[Unclenick]

There is a limit to which the powder can propel its own mass even without the added burden of having to push the mass of a bullet ahead of it. I know the military experimented with this in special guns at one time, putting .30 caliber bullets into necked-down 50 BMG and even 20 mm cases, but they didn't see much difference between the two. I've forgotten the velocities achieved, but I believe they were all under 6,000 fps.

It has to be born in mind that firing powder is not a nuclear reaction, so matter is not destroyed, and therefore the gas has the same total mass as the powder that burned to generate it. This is why you have to consider the portion of the powder mass that chases the bullet and is expelled in muzzle blast when making recoil calculations. The carbon dioxide (AW≈44) and monoxide (AW≈28) and water vapor (AW≈18) in nitrocellulose combustion products have the mass that's getting pushed. The only way to go faster is to get lighter gases.

Brickyee beat me to mention of the light gas gun. I was able to visit a lab with one used to simulate meteorite impacts to test satellite armoring. The gun was 40 feet long and was comprised of two 20 foot barrel sections about 8" in diameter and floated on air bearings during manipulation. The first section was chambered for a 40 mm casing and bored to 40 mm. The last 20 feet were about 50 cal. The breech end of the front section had an inch or two of smooth transition from 40 mm down to .50 cal. Biggest smoothbore I've ever seen.

To load and fire, a .25 cal aluminum sphere was placed in a split .50 cal Nylon sabot and inserted into the narrowed breech end of the the second barrel section. A 60,000 psi burst disk was sealed behind it. The barrel sections were interlocked and sealed. The 40 mm casing was primed and loaded with a pound of powder and a 40 mm plastic piston (looked like Delryn) was seated into it. This was loaded at the breech end of the first 20 foot barrel section and the breech was closed and sealed. A vent near the end of the first barrel section allowed a vacuum pump to remove the air between the piston and the burst disc and back fill it to some pressure level with helium (AW≈4).

When the gun fired it drove the piston to compress the helium. When the pressure reached 60,000 psi, the burst disc ruptured and let the high pressure helium drive the sabot the last 20 feet. The piston simply swaged into the narrowing in the second barrel section and stuck there as the propellant gas vented. At exit from the muzzle, the sabot separated and the halves struck a piece of armor plate with a hole in its center for the aluminum ball. This was positioned just far enough forward of the muzzle that the sabot halves would be separated and not interfere with the ball. The ball cleared the plate traveling at 17,000 fps. Nothing like a little light gas to get the ball rolling.

[jtmckinney]

peetzakilla:

I had some of the same thoughts. The book I refered to is dated 2008. It is also highly reguarded by a lot of the members here and I felt I got a lot of good information from it.

I was just trying to provide a respected resource on the subject.

I know I didn't answer the OP's question:
"Just wondering what the highest FPS that has been recorded by a conventional rifle/ammo combination."

Again, sounds like fun.
James

[Brian Pfleuger]

Originally Posted by jtmckinney

I had some of the same thoughts. The book I refered to is dated 2008. It is also highly reguarded by a lot of the members here and I felt I got a lot of good information from it.

I'm not meaning to sound argumentative, just clarifying the message.

I have a 2008 or 9 copy of that book too... but I believe the original publishing date was in the '60s (maybe, not sure, long time ago anyway) and I'm not sure that a lot of the information has been updated.

[jtmckinney]

Peetzakilla:
"I'm not meaning to sound argumentative, just clarifying the message."

No argument here.

brickeyee and unclenick had interesting post on the subject, Thanks.

OP did ask about "conventional rifle/ammo combination." Are there any appreciable gains to be had from creating a vacuum (or at least a reduced pressure) in the barrel in front of the bullet. I would think this would have to increase velocity. Maybe not enough to matter. Anyone know?

Thanks!
James

[mehavey]

Like others noted, max velocity of even marginally practical rifles powered by conventional propellants/cases is ~5,000 fps.

But if you want to get into the gas guns we played with back in the early 70's at AFWL, here's a decent writeup on the later progeny:

https://www.llnl.gov/str/pdfs/09_00.pdf

Note page 15: Would you believe ~26,000fps ?

(What's a measily decimal point or two mean amongst friends?)

[brickeyee]

I was able to visit a lab with one used to simulate meteorite impacts to test satellite armoring.

I worked on the research into what happens when hyper-hyper velocity collisions occur.

It is nothing like regular terminal ballistics.

The impacting object is turned into a plasma the energy is so high.

[Ozzieman]

I dont know if this counts but the cost would be a little on the high side per shot. 20 kilometers (12.4 miles) per second



United Press International February 23, 2001, Friday
Researchers build 'world's fastest gun'
By KELLY HEARN, UPI Technology Writer

ALBUQUERQUE, N.M., Feb. 22


Using a powerful device that generates enormous magnetic fields, researchers have shot dime-sized pellets of aluminum at speeds three times that needed to escape the gravitational pull of the earth.

Dubbing it "the fastest gun in the world," Marcus Knudson, a physicist at Sandia National Laboratories in Albuquerque, N.M., told United Press International that the device, known as a Z accelerator, can launch materials at speeds of 20 kilometers (12.4 miles) per second. A rifle bullet travels at speeds of roughly 1 kilometer (0.6 miles) per second. At that speed, a pellet could travel the distance between New York and Boston in half a minute, researchers said.

The Z accelerator is the most powerful producer of electrical discharge on earth, capable of generating 20 million amps. A household coffeepot uses approximately 10 amps.

Measuring 110 feet in diameter and standing 20 feet tall, the accelerator is filled with water and oil. When the charge is unleashed, it generates a vast magnetic field that propels small objects much like a surfboarder is propelled by enormous waves, researchers said. Originally, researchers used the device to shoot short X-ray bursts at materials to monitor their psychical behavior under extreme stress. "But one day we came across the idea of using the magnetic fields generated by the accelerator to launch plates," said Knudson. The high-speed accelerator offers researchers a cheaper means of testing how materials react under extreme pressure and temperature, a boom to officials charged with monitoring the nation's nuclear stockpile.

Researchers said they are also using the device to simulate the effect of flying debris in space. The tests may help engineers develop lighter, more durable materials for satellites and on-orbit telescopes. The accelerator could also feed a new generation of hypervelocity, or "kinetic kill" weapons. Theoretically, if designers could produce an accelerator that is smaller but similarly powerful, projectiles could be shot at speeds that would pierce heavy armor.

But certain problems remain vexing. "The military has looked into hypervelocity launchers before," said John Pike, director of Globalsecurity.org, a Washington-based defense policy organization. "Originally they were considered for the Star Wars program in the eighties but the accelerators were too large to launch into space and the barrels would have worn out too quickly." Having nixed the idea of using hypervelocity weapons in space, Pike said, military planners considered using them for ground combat. "They thought about making them small enough to put on the back of a truck or tank, but the problems of size and the issues with the barrels were still there."

Another problem is finding a metal that will not liquefy or vaporize once shot from a hypervelocity weapon. The aluminum pellets for example will liquefy after reaching a velocity over 20 kilometers per second. But Knudson said his team is trying to solve the problem by reconfiguring launch speeds. He is also experimenting with copper and titanium, which may not vaporize as quickly.

[Brian Pfleuger]

Since the question concerns a "conventional rifle/ammo combination", I don't think a magnetic gun counts.

[Garretj64]

no you wont buy that hyper velocity gun at your local hardware store, but its pretty crazy stuff!!!

[Ruark]

I'm just trying to think what that little 22-243 bullet would do to a coyote at 5200 fps.....

[Brian Pfleuger]

I'm just trying to think what that little 22-243 bullet would do to a coyote at 5200 fps.....

As interesting as it sounds, even at 4,200fps you're entering an area of seriously diminishing returns for damage potential. Speed gets you flat shooting but eventually you get to the point where you're simply blowing 1,500 ft/lbs out the other side of the target rather than 1,200, for example.

So, once you're well and truly past the "explosive exit" stage, it really doesn't get much more interesting.... until speeds get REALLY stupid, way faster than you can make a bullet go.

[chiefr]

I read an article many years ago where some wildcatter created a 22-378 Weatherby. One he figured out conventional bullets self destructed at such speed and used alloyed steel bullets, they got 7200 FPS. Barrel life was nil.

[Unclenick]

Brickyee,

The impacts at this lab were recorded by a series of super fast x-ray bursts directed locally to sections of a photographic film as the projectile passed by the sources, resulting in a series of images of the ball approaching and impacting the target. The armor turned out to be nothing more that a 1/16" sheet of aluminum with a space behind it. The ball hit the plate and mostly turned into dust except the core, which became instantly molten. Some of the molten material may well have evaporated to hot plasma, but that wasn't obvious on the x-ray. Funny business, that.

[jmorris]

By me, 5258 FPS using a 180 grain .30 in a sabot 50 BMG.