Howdy,

What’s the highest velocity a lead bullet has ever reached?

Also, a second question I have is this:
Has anyone made a rifle that shoots a 5.56mm bullet from brass & powder loading similar in size to the 7.62mm?

Cheers,

AE

I've shot lead cast bullets (no jacket only gas check) from my AR . Velocities just over 2000fps with no leading.
Not pushed them any faster....yet

Taffy

I've read in several places that the theoretical velocity limit for chemical propellants (gunpowder) is in the vicinity of 5000 fps.

For a .22 cal bullet in a .308 case look up "22-250". It isn't based on the .308 case, but it is pretty close to it.

7.62 by what?

Lead bullets only, or jacketed lead projectiles?

The .22-250 and .220Swift are two you should look at.   You can get up to the 4000fps range.  The problem is that these types of cartridges is that they can suffer from shortened barrel life.

There are also some .308Win necked down to .22ish cartridges out there, like the 22 Cheetah that goes past 4000fps by a few hundred fps.

I guess it really depends on what you are looking for.

87,000,000,000,000 fps

From what I've read, .243 with a light bullet (55 gr) will get into the 4k's also.

Quoted: 7.62 by what? Lead bullets only, or jacketed lead projectiles? The .22-250 and .220Swift are two you should look at.   You can get up to the 4000fps range.  The problem is that these types of cartridges is that they can suffer from shortened barrel life. There are also some .308Win necked down to .22ish cartridges out there, like the 22 Cheetah that goes past 4000fps by a few hundred fps. I guess it really depends on what you are looking for.

You can get sabots that shoot 22 bullets in 308 cases, reaching 4000 fps in a 30-06.  But that won't happen with a 22-06 unless you got a 30" barrel or something.  The sabot still retains the .308" diameter base, which gives the sabot base a  0.0745 square inch area for the powder to push against, at 50,000 psi that relates to 3,725 pounds of force of the bullet.  

A .223 projectile only has 0.0391 square inches of area, translating to 1,952 pounds of force with a 50,000 psi chamber pressure.  That's only 52% of the force a .308 bullet receives.  

I've seen 50-308 sabots that allow you to shoot 308 bullets in a .510 caliber rifle.  The seller advertised 5,280 fps using a 168 grain bullet in a 50 BMG.  The .510 sabot has a surface area 2.75 times that of the .308, so you can see how easy it is to get a massive amount of force on the projectile.  

I realize that the chamber pressure is not at 50,000 psi through the entire burning process, and that a faster projectile get acted on for a shorter period of time than the slower one.  The greater surface area is one of the reasons I chose the .358 Winchester as my new deer rifle, it can push a 180 grain pill at the same MV as a 30-06 with less recoil and a shorter barrel.

Quoted: 87,000,000,000,000 fps

+1

Your an Aerospace_Engineer, figure it out!

ETA - I've heard unsubstantiated claims of 6,000 fps using a 30-378 Weatherby Magnum.

From reloadersnest.com:
Highest Rifle Velocity on site: Load 1147 in caliber .22-243 Middlestead
Bullet: Berger HP MEF
BulletWeight: 30 grs
Powder Alliant: Reloader 15
PowderWeight: 50 grs
Primer: Federal 210
Brass Make: Winchester
Velocity 5278 fps

Well, if you go smoothbore, you can get pretty quick.

One of the sabot'd rounds for the M1 tank main gun has a muzzle velocity of 1740 meters/sec, or 5708 ft/sec.

example here:
tank rounds

I don't know why you could not do the same thing on a smaller scale with a lead projectile (although the tungsten and DU rounds are better for the anti-armor mission).

Quoted: Your an Aerospace_Engineer, figure it out! hr

touche!

A good scientist always conducts research before he pursues an experiment...! Thanks for your input guys!

This is good stuff, guys!

The question of whether I am asking about jacketed or non-jacketed bullets has been asked a few times. I'm interested in knowing both.

What's the highest velocity a copper jacketed bullet and a bare lead bullet has reached?

(...because I'm just plain curious, that's why!)