Handgun bullet trajectory - any general guidelines? - Page 2

Brian Pfleuger · May 22, 2011, 12:18 PM

9-ball,

Your percentages are pretty off there...

"Rocket effect" does not account for 2/3s of recoil, at least not as a general average.

The mass of the powder charge can have an appreciable effect, because a large percentage of it is being accelerated with the bullet and adds to recoil. However, certainly in the case of handguns, the powder charge is fractions of the weight of the projectile. Maybe 8grs of powder compared to a 125, even 180gr, bullet. With rifles, the effect can be greater, as I have loads where the powder actually outweighs the bullet.

On the "rocket effect", this is greatly effected by barrel length because the main factor is muzzle pressure. All else being equal, a shorter barrel produces more rocket effect because the muzzle pressure is higher.

9-ball · May 22, 2011, 03:52 PM

Excuse me peetzakilla,

you are right, my previous results were not calculated with all the exact weights, and since I estimated the recoil with a 1 kg gun but used the recoil measurements of a glock, I was a bit off.

okay, so this time I used all the exact figures:

average % of recoil energy attributed to other effects then accelerating bullet:

58.1
calculated with the measurements of 43 different 9mm loads shot from a Glock.

Mello2u · May 22, 2011, 06:16 PM

http://www.youtube.com/watch?v=otpFN...yer_detailpage
The above link shows a bullet exiting the muzzle filmed at 1,000,000 frames per second. You will notice that there is gas exiting the muzzle before the bullet. Don't know what cartridge is depicted.

This video takes the time that the bullet travels through the barrel which should be around 7/10,000 of a second and stretches it to about 5 seconds. If you watch carefully you can see a slight (very slight) bit of muzzle rise. Don't know how the handgun was secured for this video.

B.L.E. · May 23, 2011, 05:59 AM

Quote:

Originally Posted by Mike38

I have a question. I'm sure most everyone here has seen films of super high frame per second cameras slowed way down so you can watch the bullet exit the barrel. I watched one of a M1911, must have viewed it 100 times, trying to educate myself on exactly what happens durring firring. Far as I can tell, the bullet exits, and is at least 10 inches or more from the muzzle before any detectable movement or recoil is seen. So how is it that the heavier bullet shoots higher when there is zero movement of the barrel until after the bullet is well on it's way to the target?

http://www.youtube.com/watch?v=otpFN...yer_detailpage

Take a look at the above link originally posted by Mello2u. Look at the front sight of the gun while the bullet is still in the barrel, it is moving back.
The barrel and slide are locked together for the first few millimeters of recoil and so the barrel and slide recoil together while the bullet is in the barrel. After the bullet clears the barrel, the rear of the barrel pivots downward to unlock itself from the slide and the slide then keeps going on momentum to finish the cycle.

May 22, 2011, 12:18 PM	#26
Brian Pfleuger Moderator Emeritus Join Date: June 25, 2008 Location: Austin, CO Posts: 19,578	9-ball, Your percentages are pretty off there... "Rocket effect" does not account for 2/3s of recoil, at least not as a general average. The mass of the powder charge can have an appreciable effect, because a large percentage of it is being accelerated with the bullet and adds to recoil. However, certainly in the case of handguns, the powder charge is fractions of the weight of the projectile. Maybe 8grs of powder compared to a 125, even 180gr, bullet. With rifles, the effect can be greater, as I have loads where the powder actually outweighs the bullet. On the "rocket effect", this is greatly effected by barrel length because the main factor is muzzle pressure. All else being equal, a shorter barrel produces more rocket effect because the muzzle pressure is higher. __________________ Nobody plans to screw up their lives... ...they just don't plan not to. -Andy Stanley

May 22, 2011, 06:16 PM	#28
Mello2u Senior Member Join Date: February 21, 2009 Location: Georgia Posts: 1,424	http://www.youtube.com/watch?v=otpFN...yer_detailpage The above link shows a bullet exiting the muzzle filmed at 1,000,000 frames per second. You will notice that there is gas exiting the muzzle before the bullet. Don't know what cartridge is depicted. This video takes the time that the bullet travels through the barrel which should be around 7/10,000 of a second and stretches it to about 5 seconds. If you watch carefully you can see a slight (very slight) bit of muzzle rise. Don't know how the handgun was secured for this video. __________________ NRA Life Member - Orange Gunsite Member - NRA Certified Pistol Instructor "When plunder becomes a way of life for a group of men living together in society, they create for themselves in the course of time a legal system that authorizes it and a moral code that justifies it." Frederic Bastiat

May 22, 2011, 03:52 PM	#27
9-ball Senior Member Join Date: May 21, 2011 Location: Belgium Posts: 340	Excuse me peetzakilla, you are right, my previous results were not calculated with all the exact weights, and since I estimated the recoil with a 1 kg gun but used the recoil measurements of a glock, I was a bit off. okay, so this time I used all the exact figures: average % of recoil energy attributed to other effects then accelerating bullet: 58.1 calculated with the measurements of 43 different 9mm loads shot from a Glock.