SPIN DRIFT!....I'm such a dummy

[phorwath]

Originally Posted by RDM416

The chart in wikipedia shows 6.5" SD at 1000 yards. That corresponds to what I seem to be seeing in actual range results.

I have an engineering background and am starting to dig more into the science behind all this.

When I dial in the correction my groups are more centered around my POA.

But in the mean time, I am going to dial in what my ballistic program shows for spin drift.

'Roger that' on all four of the above sentences. Except for the second sentence. The researching part is past-tense for me.

I'm experiencing about the same SD at 1000 yds. Between SD and Coriolis-caused drift (60.5 degrees North Latitude), I typically experience about 10" rightward bullet drift over 1000 yds. Which is very close to the predicted dope using LoadBase 3.0 ballistic software.

I noted this drift the very first time I moved back to 1000 yds about 3 years ago - before I owned any ballistic software. So I didn't experience the drift because I knew it was expected. Quite the contrary. AFTER experiencing this unexplained drift, I spent a lot of time researching the cause(s) of this rightward drift. Now I believe I understand it, and dope for it on all shots past ~5-600 yards.

[Bart B]

Originally Posted by RDM416

What I don't understand is why the competition shooting community seems to have such contempt for the LR hunting community. You BR guys will always shoot better groups. You get benches and rests, wind flags, sighters and fairly level terrain.

I am part of the competition community. I don't shoot BR. I don't use benches; I lay on the ground holding the rifle to my shoulder with my hands. Flags are only about 20% of what I watch; the other 80% is the air. I don't always get sighters.

I only have contempt for folks who think there's only one way to shoot small groups and make claims that contradict the laws of physics.

[paphil]

Spin and Coriolis Drift

That was a great link Bart, here is another by Brian Litz that also applies.

[vendetta333]

i just read this whole thread, and the article and it was fantastic! god i cant wait til i can afford to get into practical long range competition!!