Bullet defying gravity?

[raisedin32]

I been playing around loading a 55gn nosler ballistic tip for my .243 with right around 4000fps . I have a good 100 yd zero and when I go out to 200 I'm hitting 3" high. My ballistic calculator says I should be dropping a little more than 1/4". So you can see my issue. Had a buddy shot the gun he was also grouping them 3" high. Any thoughts?

[Red Rabbit]

With a 100 yard zero, you should be closer to 1" low at 200yds. (doucle check your program)

Double check your 100 yard zero group.

Are you shooting off the same bench rest at 100 and 200?

Maybe your scope went TU. Double check screw tightness for rings, base, action.

[raisedin32]

Double checked scope its good. Shooting from the same bench but the target was about 30' higher in elevation from 100 to 200. Could that throw me off that far?

[yotebuster]

This is a good example of why ballistics calculators don't always work the way you'd like them to. They figure for a 1.5" scope height and the approach angle of line of sight vs. line of flight can vary based on rifle/base/ring/scope combinations. A bullet usually crosses line of sight (going up) at around 25yards, then comes back down around 100 yards (if that is your zero). BUT, it may cross sooner or later then that based on the angle of your line of sight/line of flight. Soooo, there is a chance that your barrel is "pointed higher" if you will, or "pointed lower". This is why it is imperative to always shoot your rifle at all distances you plan on shooting and not just sight it in at 100 and print off a ballistics chart and go hunting.

[oz31p]

he was shooting at 100 and 200y on the same session. he checked the calculator afterward. i think his barrel is pointing up and the bullet as not started to come down untill after 200. plus the 55g is a zinger. his 100 groups is dead on.

[Tines]

This is a good example of why ballistics calculators don't always work the way you'd like them to. They figure for a 1.5" scope height and the approach angle of line of sight vs. line of flight can vary based on rifle/base/ring/scope combinations. A bullet usually crosses line of sight (going up) at around 25yards, then comes back down around 100 yards (if that is your zero). BUT, it may cross sooner or later then that based on the angle of your line of sight/line of flight. Soooo, there is a chance that your barrel is "pointed higher" if you will, or "pointed lower". This is why it is imperative to always shoot your rifle at all distances you plan on shooting and not just sight it in at 100 and print off a ballistics chart and go hunting.

 

+1

[raisedin32]

Anybody have any suggestions on a remedy for this cause aiming three inches low on a coyote at two hundred yards is no fun.

[Coach]

I may be a little off-base here, but 55 grains at 4000 FPS??? Have you ever shot an airsoft gun? Little plastic BBs .2 g shooting around 350 FPS. Their flight pattern is very irregular due to being so light for that speed. Sometimes the actually curve upward in flight.

 

I would suggest your "abnormal" bullet performance is more a result of pushing too light of a bullet at that speed than anything else.

[AZbowhntr]

If the bullets were too light and going too fast I think that you would see that in the accuracy. I would shoot at 25 yds and see where you are hitting. As someone said you should be about dead on. I bet the problem is in the scope level. But I don't know the technical term.

[catclaw]

I cannot explain what you are describing. If you are dead on at 100 yds with a typical scope mount your bullet should be BELOW your 100 yard zero at 200 yds. If you were to mount your scope 6" above your bore, you could induce the phenomenon that you are seeing. Having shot 10s of thousands of high velocity rounds I am very skeptical and would have to see it to believe it I guess. The angle of departure etc has nothing to do with what you are describing. The only way a bullet would be "rising" to the line of sight would be to mount the scope high enough to create this effect which in this case, would be somewhere between 5" and 6" above the bore.

 

Could be that your rifle is stringing vertical and just showing up at 200, your scope has a ton of parallax and is shooting totally different at 200 than 100? What you are describing is NOT a good thing.