Radar-Guided Rifle

Well, let's take 3200 FPS as the muzzle velocity, assume that your target is 500 yards away. That's a reach for an AR-15, but that's ok. That gives you two seconds to alter the bullet path.

How long will the " non-magnetic barrel extension" be?

Now, about cad on laptops. I put AutoCad on my laptop when I was learning to use it. Obviously the small screen will be a problem for shop use, but ......................

I could zoom a detail to fill the screen.

Dadburn kids and your toys! Git yerself an '03 Springfield and you won't need any correction doodads out to better'n 1000 yards. Everbody knows .22s is fer shooting rats. Hmph!

What's wrong with a nice, fat 0.5 Barrett ?

A complementary radar-informed spotter on the side, is just fine

Nope, not gonna happen. First an electron beam has very little mass and very high electrostatic charge for its mass. The force on the electron is determined by the Lorentz Force equation, F=q( v x B ). So applying Newtons Law of motion to this one gets m a = q( v x B ).

Now a bullet is a neutrally charged particle, so the Lorentz Force equation does not directly apply. Instead one must use instead the classic force between two magnetic pole equation of

This more complicated equation does derive from the Lorentz Force equation and will require more spatial mechanics to accurately prove my point. So let me put this in another perspective.

Most bullets are made of non-magnetic material like lead. So a magnetic field will have just as much a force moving the air around the bullet as moving the bullet itself. The copper of a jacketed bullet will have slightly less permeability than air. Now one molecule of Nitrogen has a mass of about 23E-27 kg. One electron has almost 10E-30 kg. Lastly a light weight 30.06 bullet weighs 3E-3 kg. Granted the electron beam will be moving close to the speed of light, 3E8 m/s. The 30.06 bullet has a nominal muzzle velocity of 7E2 m/s. The vastly larger 27 orders of magnitude more mass the bullet has over the electron quickly swamps out the 6 orders of magnitude difference of velocity. The momentum difference makes direct magnetic steering of a bullet impossible.

Thanks Fred. You kind of lost me with the explanation, but I'm sure you know more about this than I.

My thoughts on the subject were: a projectile made of steel with a sabot(similar to the shells for a 16" gun on a battleship); A short rifled barrel and an extension extending from the muzzle which contains the deflection coils.

Guiding can be done by measuring the error in the bullet trajectory (by radar/laser), and then applying a correction to an ordinary rifle barrel for the next shot (using gyros, accelerometers and push/pulling weights against the barrel tip).
I see the hard part as fixing a target in space-time so the software can compare the bullet vector to the moving target and compute a correction.
Perhaps the same hardware could track the target and the bullets. You just put a shallow 3-corner microwave/optical reflector grating on the back of the bullets to track them, and use interferometry/Doppler for measurement.
A Sony PlayStation3 might have almost enough processing power to strike the firing pin for you when the barrel is coming into alignment for another shot.
...I think this is already invented: an antiaircraft/antimissile rapid-fire cannon used on naval vessels. It sure isn't handheld.

This was sort of covered by myth busters:

Well put and a GA. Much more poignant than my confusing physics.

A little bit of "rifle-ology", for anyone who actually cares.

The capabilities of a rifle are of two categories, one being it's range, the other it's accuracy.

Range depends upon two factors, the muzzle velocity, and the ballistic coefficient of the projectile. Muzzle velocity is pretty obvious, the faster a bullet leaves the weapon, the further it'll carry, all things being equal, which they aren't.

Ballistic coefficient is the measure of how well a bullet slips through the air, which translates to how well it bucks the wind and maintains velocity. Longer, heavier bullets, having higher ballistic coefficient, tend to travel further for a given muzzle velocity. They also tend to be more accurate.

So, a .22 caliber bullet weighing 55 grains with a muzzle velocity of 3300fps (5.56mm, 3.73gm, 1000mps) will carry out to 400 meters before it simply runs out of energy. A .338 caliber bullet of 250 grains (8.59mm, 16.2gm) with the same muzzle velocity on the other hand will still have significant energy at around 1200 meters. This is why the big (really big) naval guns can accurately hit targets 40 km away.

The other factor is inherent accuracy. When a rifle discharges, the steel barrel vibrates like a tuning fork. The more precisely a cartridge load is matched to the rifle, the more accurate the rifle, since the bullet leaves the muzzle closer to the exact same point in the oscillation cycle of the barrel. And of course some barrels vibrate less than others. Most long-range weapons have very heavy barrels for this reason, and barrels heavily wrapped in carbon fiber are acoustically dead, or very nearly so.

Accuracy is measured in minutes of arc. This is determined by clamping a test weapon into a stand and firing groups of three to 5 shots at a target 100 meters away. If the shots all fall within a 1 inch circle, the weapon has 1 minute accuracy, which is considered to be reasonable accuracy for most purposes. But at 400 meters, this group will open to 4 inches, and 1000 meters, 10 inches. Obviously, for long-range weapons, greater accuracy is desirable. The most accurate weapons can achieve close to 0.1 minute accuracy at 1000 meters.

The rest is in the hands of the rifleman.