Very High Velocity (+5000 FPS in 308)

not really seeing getting the 308 anywhere near 5000 fps . I am still waiting to see if that i think he is a kid on you tube makes a more powerful laser than he already has. or the sound gun that can render whole crowds of people unconscious in seconds . Or a shit your self gun if that is even a thing it would be a great prank at parties .

i wanna see his attempt at a death star lol
or this thing

IMO Getting a bullet to velocities over 5000fps in a smooth bore barrel is not that big a deal. The trick is getting it to go where you want it to. As I’m sure you know that’s why the advent of rifling was such a game changer. He uses smooth bores because at those velocities rifling will actually spin bullets apart. I’ve actually seen 55gr hpbt bullets disappear into a puff of smoke at around 4000fps out of my 22-250. I doubt any gyroscope tiny enough to fit in a bullet could survive the acceleration from 0.0fps to 5000fps in a split second. Something that small would be too fragile to withstand the resultant g-forces. It could happen someday but not in my life time. But that’s just my humble opinion.

I read an article in a magazine in the 90’s about a guy who was able to get crazy velocities. His setup wasn’t like today with the exposed case head. His cartridge slide all the way into the chamber, like if you dropped an short cartridge into a longer chamber. Then the bolt head went up, into the chamber as well. This completely sealed the cartridge inside high strength steel.

How he extracted was unique. In the case head was a hole with the rim on the inside that a hook snapped into.

He was a researcher and according to the article he was reaching speeds in excess of 10,000 fps using small, lightweight projectiles. It looked and functioned like a traditional rifle.

Everybody wants to reinvent the wheel. IMO those DARPA bullets that could track and adjust in flight were a much cooler idea.

I had to google the 5000fps. I found a 2015 article from accurate shooter and it said a guy was getting muzzle velocities of over 5200fps. The round was 224 McDonald, basically a necked down 6BR with 30gr .22 cal Berger bullets. The rig he used, Remington 700 with a 30 inch 1:12 twist Hart barrel. I didn’t see any mention of barrel life or if the bullet ever made to a target but evidently 5000fps is old news. I’d have never thunk it

I’d invite your attention to my childhood - check out the Mach 5: a .50 BMG necked down to .375 before ELR comp was even a gleam in someone’s eye. The name tells you what you can expect...

As to smooth bore systems running 1600-1800 m/s, that describes the Rheinmetal 120mm smooth bore currently fitted to an array of western MBT provided they are using current ammo and at least an L44 barrel. If you’re familiar with the APFSDS, it is roughly a third the size of the bore. I find that relevant because, proportionally speaking, that means we might consider a .50 cal bore built around “normal” small arms calibers.

See again my childhood. You could buy sub caliber sabots to load your .50 BMG with smaller pills at super high velocity. The military version of this is the SLAP, of course. We looked at it for use in CSW - the .50 BMG variant was successful and somewhat wide spread, the 7.62 mostly flopped. Two interesting points - one of the Scandinavian countries was using a 7.62 NATO SLAP variant (@ ~4400 fps) in their sniper weapon systems and supposedly cited about a 33% degradation in accuracy; for a long time you could buy “accelerator” ammo in .30-06 that featured a little .22 cal bullet @ roughly that same ~4400 fps. No reports from me on accuracy of the latter.

Hi,

O man, where to start......

1. There is no gyroscope that is going to stabilize a bullet that is not pretty much already stable..that is just not the intended purpose of a gyroscope; it is designed to assist not completely manipulate.
2. The reason he is doing it with smoothbore is because if he tried with rifled barrel the pressures due to engraving force, etc would more than likely detonate his firearm.
3. Even the Exacto program was closed and everyone read out of it because once the range testing got underway there was no significant improvement in accuracy with qualified shooters and deemed a failure once projectile was not supersonic unlike traditional projectiles of proper design.
4. I have a Mach V reamer and barrel (RIP Klause) sitting here with me and there are some major issues with it so it is not even in part of discussion, lol.

Sincerely,
Theis

I got 2400 FPS out of my 4” GP100 once.

No free lunch. You have to go to something like a fin-stabilized projectile where you get the CoP behind the CoM. Obviously the length of the projectile and cartridge gets absurd. It might be an interesting thing to play with in a real pressure test barrel but my main concern would be with the available precision.

At first glance it seems like a big balancing act of projectile vs. fin diameter vs. length vs. functional ammunition. Getting CoP behind CoM while also minimizing drag. The other thing is that drag increases a LOT the faster you go. Juice might not be worth the squeeze.

Ledzep said:

No free lunch. You have to go to something like a fin-stabilized projectile where you get the CoP behind the CoM. Obviously the length of the projectile and cartridge gets absurd. It might be an interesting thing to play with in a real pressure test barrel but my main concern would be with the available precision.

At first glance it seems like a big balancing act of projectile vs. fin diameter vs. length vs. functional ammunition. Getting CoP behind CoM while also minimizing drag. The other thing is that drag increases a LOT the faster you go. Juice might not be worth the squeeze.

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It's definitely not worth the squeeze. Fin design for a super sonic projectile isn't trivial. Fin design in a very small supersonic projectile just isn't worth it.

If you loaded a sub caliber mono projo you could probably do it, not sure if 308 case has enough gas.

Remington got mid-high 3000s with this stuff back in the day.

Hi,

Sabots are notoriously inaccurate due to disturbance of the projectile by the sabot as it separates.

Sincerely,
Theis

I figured someone would mention sabots... I don't believe in them, especially for small arms. Dubious reputation for (in)accuracy in every instance that I'm aware of.

State of the art at present might be "minute of tank" - napkin math...follows...1 MRAD @ 1000m = 1m; 1 MRAD @ 3500m = 3.5m, a k-kill requires 2m or better CEP I'd estimate...so, call the M1A2 or Leo 2A7 a ~.6 MRAD weapon system...which @ 100 yards is approx. 2 inches...so, a roughly 2 MOA weapon? How does that compare to the variant adopted by the Swedish for use in the AI AW back in the day? If anyone knows, it's gotta be someone here on the Hide.

Now I want to see someone shoot an ELR match with an M1A2...that'd be something. A PRS match might be even better! Hard on the targets, though...

Hi,

LOL but we can already blow through all those targets with the bimetal "solids".....Monolithic designed for a backdrilled/pressed in tungsten "core" per say.

It allows us to change the CG, add mass, add sectional density, etc yet REDUCE the length.

O and they are designed to have no max velocity stabilization that exist is current max produced projectiles.

Sincerely,
Theis

Are you trying to steal my joy? Aside from being fun to watch tanks shoot stuff, it's just plain common sense. Obviously if a chunky, 25+ pound rifle with a 30 inch straight taper barrel is good and more weight is always better than 160,000 lbs of gyro stabilized 120mm smooth bore is the natural direction of the sport.

DJL2 said:

Are you trying to steal my joy? Aside from being fun to watch tanks shoot stuff, it's just plain common sense. Obviously if a chunky, 25+ pound rifle with a 30 inch straight taper barrel is good and more weight is always better than 160,000 lbs of gyro stabilized 120mm smooth bore is the natural direction of the sport.

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Even then, someone‘s gonna bitch that a “no tripod stage“ is unfair...

Kyl
Kyl
Kyl

it is not fair you should have to shoot iron sights lol and feel lucky to even have that ... lol see someone had to bitch

THEIS said:

Hi,

Sabots are notoriously inaccurate due to disturbance of the projectile by the sabot as it separates.

Sincerely,
Theis

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The m1 tank seems accurate enough

MarinePMI said:

Did someone say “308 sabot”?

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I wish I still had the 30-06 version I was given decade ago now that I have a chrono

Now whenever I hear sabots I sorta have to laugh. I still think the apfsds rounds are awesome. The first Transformers movie completely misused the term. They were supposedly shooting sabot rounds out of m203 launchers to take out the transformers.

spife7980 said:

I wish I still had the 30-06 version I was given decade ago now that I have a chrono

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I have 2 more rounds of that stuff. If I remember correctly it was well over 4000fps through a crappy RCBS chrono. I'll test them again in my hunting rifle when I get a chance.

Back in Harry Pope’s day some guys were getting around 4000 out of smooth bore 30-06 rifles. This ain’t new.

I think if people started getting sub moa accuracy out of something going 5000 fps, there might be something to talk about. Until then, this is just noise.

Needs the form factor to make it worthwhile too.

Smoothbore small caliber weapons went out with the Brown Bess as the Brits learned in the Revolutionary War and there is nothing on the horizon to make smooth bores come back as a practical weapon.

Many moons back, P.O. Ackley experimented with is .22 earshpittenloudenboomer, otherwise known as a 22-378 Weatherby of his own design. With the powders of the day and a long barrel he was getting pretty good velocities but the barrel lost about the first eight inched of rifling in 100 rounds or so. Not exactly practical.

As far as sabots go, I tried loading 30-06 sabot rounds years back (sabots still available from E Arthur Brown). Good velocity, barrel wear seemed minor, accuracy was as good as 2 moa once in awhile. Not the equal of one of my 22-250s.

My 22-250 AI will hit 4200fps with a forty grainer, but with the expected barrel life I only shoot it when I want to vaporize something. It is quite accurate. Word of caution, stay away from Norma brass, it's soft and doesn't last even with a sane load.

My lightweight elk rifle in 300 RUM will hit 3850 fps with a 125 gr Nolser BT, but it isn't much fun to shoot with no brake even with a light bullet. Recoil is very fast. It has done a number on coyotes though, about like a 'chuck hit with the 22-250 AI. It's maybe a one moa load at best.

Can we get someone to shoot a KYL rack with an M1?

Kevin1 said:

We see a bunch of videos of people shooting stuff. What would really be cool is somebody making a video of shooting some AR500 plates with a 200 gr (steel core?) round out of a 308 smoothbore travelling at 5000FPS……Here’s a practical application for your naysayers……Entertainment…..

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Fair enough but I can think of much more entertaining things to do with the money it would take to execute that venture.

Kevin1 said:

I have recently discovered this guy’s YouTube channel and love what he does. He’s more into older guns and has a very extensive collection.
I was fascinated by this video about his empirical experiments on hypervelocity.

Basically, with a smoothbore 308 and fast burning powder (and some other intricacies explained in his video), he’s pushing bullets at 5000FPS. That’s a laser like trajectory with energy higher than 50BMG.
The limit is that bullet doesn’t spin and is not stable. He thinks it should be possible to put a gyroscope inside the bullet.

I found his video very interesting and thought I would share. I’m not sure if pushing a bullet at that speed has any immediate practical applications (expect for the military).
Can very high velocity bullets be the future? I don’t know…but it sure sounds cool.

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Very bad idea! A sabot in a non muzzle brake 50 BMG with a tungsten carbide bullet is a much better proven way to achieve hyper speeds. A too high a spin rate will cause bullet case to fly away. M-1 tank rounds are a good example. If you do test any unproven loads please use a ransom rest and a very long string to fire the weapon.