Does a bullet leave the barrel of a gun before the kick of the gun would change it's trajectory?

Question

In other words, if I pointed a gun directly at something in front of me, such as a coin on a desk, and pulled the trigger, would the bullet hit the coin, or do I have to compensate for the kick and aim lower than where the coin is?

Answer 1

Realistically, no. The recoil stems from the explosion of the powder in the cartridge. Being encased in a metal barrel, this explosive energy has only two directions in which it can travel... forward and back. Since the front of the barrel is open, then the majority of the explosive force escapes there, which in turn propels the bullet.

The part of the energy that gives the recoil is moving strait back. The reason you feel and see the barrel coming up with the recoil is due to the design of the rifle and the way you hold it. The energy is directed straight back into your shoulder. Your shoulder rocks back, acts as a fulcrum which lifts the barrel while the butt stays in place.

With the initial explosion, the barrel is recoiling in the exact opposite direction of the bullet, so there is no changing the angle of the trajectory. Due to the bullet's velocity, the round is well clear of the barrel before the end of the recoil pushes the barrel up.

Answer 2

If you have adjusted the sights to hit the target, you've already adjusted for recoil.

Let us use a 4" barreld M-686 .357 Magnum and two different loads. One is a 125 grain JHP at 1275 fps, the other is a .38 SPL +P loaded with a 158 gr. SWC at 900 fps.

If you use the same sight setting to shoot both loads, the 125 grainer at `1275 fps will hit the target lower than the slower bullet. The reason?

It is generally accepted that the slower bullet takes longer to exit the barrel and gives recoil more time to work on the weapon, hence the barrel is higher when the bullet leaves the barrel so it hits the target higher. Conversely, the 125 grain bullet leaves the barrel faster with less time for recoil to affect the muzzle and therefore hits lower on the target.

That make sense?

Doc

Answer 3

There is no significant barrel movement during the time that the bullet is in the barrel. What little there is is mostly in-line with the barrel. If we want to have a pedantic mathematical argument, well yes, there was movement and it will cause a different flight path and impact point. But as an engineer I deal with practical solutions, the recoil is 99.99% consistant and the sight adjustment has already allowed for it.

The Lee Enfield happens, by luck, to be self compensating at medium ranges, of the order of 500 yards. The way the barrel vibrates during firing shoots the faster bullets slightly lower, but only enough to compensate for the shorter time that gravity has to work on them. An infinitesimal amount, but Lee Enfields are often shot at 1200 yards on Stickledown at Bisley, a range where even the rotation of the earth is important.

Answer 4

Doc is correct. The recoil of a firearm DOES affect the point of impact. It is normally corrected by the process of sighting in. This is more easily demonstrated with a rifle than with a handgun by virtue of its longer barrel.

For instance if you go from a light fast bullet to a heavier bullet in the same rifle, the bullet will leave the bullet later and therefore give recoil more time to occur. This means that the barrel will be pointing a bit higher and the strike of the bullet will be higher at the same point of impact, within a specified distance.

Shooters have known this for years and years. It is easily demonstrated and with today's video capability you can see it occur.

Good luck

Answer 5

YES,,,,But the "Kick" that you describe is the reaction of the gunpowder and subsequent explosion of the cartridge as its fired. It has connection or effect on the trajectory or for that matter you're point of aim either. As you described the scenario the bullet would have already struck the coin before you felt the actual recoil. There is no need to compensate for anything. Trajectory only becomes an issue after the bullet leaves the barrel at a distance and the force of gravity pulls it earthward at a calculated rate. I hope this answers your question.

Answer 6

Yes and no. For something as big as a coin in your example, you'll hardly see it, but barrel whip is an important aspect of accuracy. There are sine-wave-like "harmonics" within the barrel as the bullet and hot gasses travel down it, very much as if you were shaking out a rope. They're infinitessimally small but important, as handloaders or people with Brownings that have the "BOSS" on the end can testify.

Answer 7

you dont have to worry about that. a bullet is real fast. it's out of the barrel and has probably hit that coin (if you didn't miss) before you felt that kick

Answer 8

Issac Newton: 3rd law.
''For every action there is an equal and opposite reaction.''

If you've aimed well, the bullet is being pushed toward the target while the weapon is pushing toward you.