spin drift & Coriolis effect

[rem]

here is some info about spin drift and Coriolis effect.
Far Out Shooting: Spin Drift and Coriolis Effect

does anyone have experience with these?

[WyoElk2Hunt]

There was an article on TV about the 30/40 Craig rifle and the flip up sight for long range shooting that it had a wire in the sight to account for the spin drift as you elavated the sight. This was during the Spanish American War so they knew about spin drivt way back then especially with heavy round bullets. Don't know about faster bc bullets.

[tresmon]

I teach it in detail in my LONG Range shooting Seminar.

I disagree with the blog guys statement that he feels it doesn't matter if you not going to be making 1500y cold bore shots.

For my long range rifle Coriolis is worth 3" right at 1000 yds, a range I shoot at frequently.
Coriolis is worth "about" (too lazy to look up the exact figure right now) another 3" right.

So if I guess what the wind is going to do to my bullet @ 1000 yards perfectly ("perfectly?" basically not possible) set my sights perfectly for 1000, break the shot perfectly, the ammo & velocity is perfect- I'm still going to miss the mark by 6" due to Spin D and Cori alone.

Now Me and every other HONEST down to earth shooter will admit they need all the help they can get for long range cold bore shots. We estimate the wind but will be a little off. Our MV varies shot to shot. All these minopr unavoidable erros stack up in long range shots so yes you had better account for Cori & spin D. We need all the help we can get at long range.

As a side note: if we inhabitants of the northern hemisphere were smart we'd shoot barrels with left hand twist rifling. This would pit spin drift and cori against each other and mostly cancel the two out!

Come to class!
TresMon's LONG Range shooting class: Nashville,TN 3-19

[BlackSS]

Originally Posted by tresmon

As a side note: if we inhabitants of the northern hemisphere were smart we'd shoot barrels with left hand twist rifling. This would pit spin drift and cori against each other and mostly cancel the two out!

Come to class!
TresMon's LONG Range shooting class: Nashville,TN 3-19

Why don't we have LH twist barrels?

[tresmon]

You can order a LH twist bore from about any custom barrel manufacturer...

My guess is to our use of RH bores is that we just live in a RH world. I don't have a technical answer nor do I know if their is one...

However for trivia, the ol' .303 british round & rifles were LH bores...

[rscott5028]

As a side note: if we inhabitants of the northern hemisphere were smart we'd shoot barrels with left hand twist rifling. This would pit spin drift and cori against each other and mostly cancel the two out!

Stupid questions:

(A) Wouldn't it depend on whether you are shooting north or south as to whether coriolis would take your bullet left or right?

(B) Why did the US military abondon their experimentation with left hand vs right hand twist?

[rem]

it seems that the only way to deal with this is to figure out what your bullet does. I can't imagine 2.5" at 1000 really maters. if you can shoot 2.5" groups @1000 then it seems it would matter. 2.5" groups win bench rest compations. the smallest temperature change will make the bullet miss at 1000 yards