Is 5,000 FPS possible?

One day I buy a chrono, then I will find a 100 gr solid copper 30. bullet and stuff it over 100 gr of RL 25 in a 300 RUM. Just because.
 
For what it's worth, there is published load data using saboted .22 caliber bullets in .308 caliber cartirdges which shows *well over* 5,000fps.

Several other cartridges are also shown on the page.

The trouble with getting really high speeds is partly due to the increasingly small amount of time that the bullet spends in each remaining inch of barrel. For instance, QuickLoad thinks you could fire a 55gr Accelerator round out of a .300Weatherby Mag at 5,100fps from a 30" barrel. It takes the bullet 0.4ms to cover the first 3 inches. Even at constant speed, the last 3 inches (at 5,100fps) would only takes 0.016ms. So, it takes about 24 times longer to cover that first 3" than the last 3, and you've got about 7,000psi acting on the bullet at the last 3 compared to an average of about 33,000psi in the first 3.

What would really be interesting is a barrel that could have multiple charge ports along it so more pressure could be injected as the bullet passed, so as to maintain a relatively constant 65,000 psi behind it.

Talk about your muzzle blast. :eek:
 
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What would really be interesting is a barrel that could have multiple charge ports along it so more pressure could be injected as the bullet passed, so as to maintain a relatively constant 65,000 psi behind it.
Click to expand...

A Heinlein "booster gun."
Also the real world Nazi Super Weapon code named "High Pressure Pump."
It didn't work, but the Krauts were in there swinging.
I think the concept was seen in the 19th century.
 
In the 21st Century, we (might) have the technology to actually do it though.

The time delay between ignition of an explosive and the pressure build would be a major problem though. Considering that it only takes 0.016ms for the bullet to travel 3" at the 30" mark.

You might have to do it with some sort of explosively powered piston that would inject super pressurized, very hot helium gas... or something. I'm pretty good at physics but I'm no engineer and the details of such things have decades ago left my pizza makers brain.:rolleyes::o
 
Something I always wondered about. Stick powder is sometimes perforated in the center and disc powders are sometimes perforated. These are both intended to get more surface area ignited as pressure starts to build.

Let's talk about a possibility. Assume that we could create solid pellet charges. The things would be case diameter and inserted before creating the neck .it has a small internal channel that burns powder from the outside inward, inward from front to back as well . We could even create multistage pellets that would start slowly and accelerate to an even faster burn. The point would be that normal granulated powder in normal ammo allows an early spike in pressure, with rapid drop off. A shaped, composite round with controlled ignition could maybe allow that pressure to remain at peak or near peak farther up the barrel.
 
That's the way most slow magnum powders work on. The problem is they need a decent amount of pressure to keep burning, without going so accelerated that they pressure spike. Starting with a mostly solid material would probably not give you enough initial pressure to get into the right burn range. The German G11 round was solid, but used an initial detonating charge to fracture the propellant for extra surface area and rapid enough burn.
 
A composite may have a layer of fast, high pressure generation compound along the primer channel, a much slower burning body to build pressure down the barrel, and the last part of the charge to go woul be very fast, to boost the pressure again in the last few inches.

Without that center channel, there'd be risk that the charge would block the throat and the powder charge would backfire.

It's obviously not going to happen. Simple economics. Powder can be made in batches of several tons, day after day, and metered into ammo in microseconds. Making composite pellets isn't going to be as cost efficient as turning out millions of tons of ball powder. Loading wouldn't be an issue, it wouldn't be any different than seating a bullet. Lines would have to be rebuilt.
 
Personally, I believe with the advancements in technology 5,000 fps will be easily reached, mebbe fairly common, a few years in the future...
 
Cordite was loaded into bottleneck cases before the neck was formed.
Before that, the black powder charge of the .303 Mk I was compressed into a long pellet with axial hole. The technology for the Briandg System was there a long time ago.

Of course there is a special name for a solid grain with center perforation so it burns from end and center (but not exterior)... solid rocket booster.
 
I never be ever that a printed gun would work, but with $100,000 equipment and an incredible amount of B.S, a company can claim to have printed a 1911 that "works."

What I know of that project is that if you put thousands of people working on something like that, maybe you can achieve some kind of success, but success at such a high cost and poor practical returns that it's almost shameful to boast of it.

My question on the subject has always been for practical purposes, meaning economically feasible, useful, and available. When we reach 6k with a rifle that could qualify for bench competition, and be accurate enough for ultra long shots at gophers, with rounds that cost about as much as .50 bmg, I'd call that success
 
Jim, all correct. The booster idea is really the key. There is no drop off in thrust and there is constant acceleration, if it's done right. If we can create rounds with full length acceleration, a round that reaches 1k from a three inch barrel might be faster in a full length barrel.
 
A duplex charge pellet cool
I think a propellent engineered on the molecular size would be the best option. Say you could get it to operate at peak pressure and be completly burnt in a 24 inch barrel
 
The one thing that I am afraid woul absolutely fail is that it wouldn't be consistent enough for great accuracy. Ball powder will do one thing well, within microseconds, that entire charge will be in full ignition, so, overall, every round should be practically identical. Using random, chaotic events. Flip 1,000h coins, and no matter how often you do it, you're going to come up very even.

Making the actual solid core, especially multi stage, if there is a hiccup of any sort,the acceleration falters, you may wind up with high standard deviations in MV. Another reason why that ideA is probably an orphan cause unless experimentation shows that mil spec 5.56 velocities could be boosted at least 2-300 fps,or some other huge benefit comes up.

If the program ever gets off ground, they will have to create a completely different cartridge, as it would probably not be safe in standard arms. Higher pressure at gas ports and muzzle, and having a very high pressure blast at muzzle may not be good.

Just something I've thought about for many years, but never expect to see.
 
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