The Firing Line Forums - View Single Post - Bullet Trajectory different than computer model

**Mal H** · August 10, 2005, 03:51 PM

Ok, I'm still confused - not that uncommon.

As I see it, only 3 things can cause the phenomenon you are experiencing if all other factors are as you determine them to be (scope, distance, etc.):
1) You are shooting in a near vacuum,
2) You have changed the gravitational constant,
3) Your muzzle speed isn't what you think it is.

I believe only #3 is one you have some control over.

You say "That adjustment [at 800 yds] had my group basically centered on the target." The bullet will be falling rapidly from 800 to 1000 yds. You added around 1 MOA adjustment and the bullet is impacting very high on the target at 1000 yds. IOW, the bullet is actually rising from 800 to 1000 yds, because 1 MOA is not enough to account for the fall that is expected between those two distances. I'm not sure what I'm missing, but it's something, and it's important.

August 10, 2005, 03:51 PM	#15
Mal H Staff Join Date: March 20, 1999 Location: Somewhere in the woods of Northern Virginia Posts: 16,955	Ok, I'm still confused - not that uncommon. As I see it, only 3 things can cause the phenomenon you are experiencing if all other factors are as you determine them to be (scope, distance, etc.): 1) You are shooting in a near vacuum, 2) You have changed the gravitational constant, 3) Your muzzle speed isn't what you think it is. I believe only #3 is one you have some control over. You say "That adjustment [at 800 yds] had my group basically centered on the target." The bullet will be falling rapidly from 800 to 1000 yds. You added around 1 MOA adjustment and the bullet is impacting very high on the target at 1000 yds. IOW, the bullet is actually rising from 800 to 1000 yds, because 1 MOA is not enough to account for the fall that is expected between those two distances. I'm not sure what I'm missing, but it's something, and it's important.