Bullet drop and the Coriolis effect

[aerophex]

“More important things can go wrong, and besides, assuming your target is standing, what’s a couple inches up or down?”

Really, Cecil? I was shocked at this one line of pathetic ineptitude in an otherwise well written answer.

Do I really need to point out the obvious error in this logic?
At 1000+ yards, a few inches is the difference between a head shot and a brisk walk home versus a miss and running for your life from enemies because you needed two shots and gave away your position.

The same principal applies to long range target shooters, accept the outcome is not life vs death, only silver vs gold.

Honestly, I was so flabbergasted by this remark I had to sign up to comment on it. I practice long range shooting and have built the Coriolis effect into my sights; thankfully I always shoot in CO so I do not need to adjust them. Military snipers traveling the world will adjust their sights accordingly.

[C_K_Dexter_Haven]

Welcome to the Straight Dope Message Boards, aerophex, we’re glad you’ve joined us.

When you start a thread, it’s helpful to other readers to provide a link to the column under discussion: saves searching time and helps keep us all on the same page (so to speak.) In this case, it’s: How does the earth’s rotation affect the path of a bullet? - The Straight Dope

No biggie, you’ll know for next time, and, as I say, welcome!

[Blakeyrat]

@C_K_Dexter_Haven

Welcome to the Straight Dope Message Boards, aerophex, we’re glad you’ve joined us.

When you start a thread, it’s helpful to other readers to provide a link to the column under discussion: saves searching time and helps keep us all on the same page (so to speak.) In this case, it’s: How does the earth’s rotation affect the path of a bullet? - The Straight Dope

No biggie, you’ll know for next time, and, as I say, welcome!

Off-topic, but have you guys ever considered having your PHP guy just modify the forum so the URL gets inserted if the user clicks the “comment on this column” link? Hell, you could do it in a few lines of JavaScript if your referrer’s good.

[Una_Persson]

@Blakeyrat

Off-topic, but have you guys ever considered having your PHP guy just modify the forum so the URL gets inserted if the user clicks the “comment on this column” link? Hell, you could do it in a few lines of JavaScript if your referrer’s good.

I agree, that is a good idea. One problem however is that many times the person commenting does not have an account or is not logged into the SDMB, so the link would need to be maintained and passed on to the PHP through either the (1) new registration process (which I’m not sure is possible), or (2) the login process (which may be possible). I’m not saying it can’t be done, but it could be a little more involved than it may sound at first. I don’t know, perhaps a current version vBulletin expert would have a more informed opinion.

[squidfood]

@aerophex

I always shoot in CO so I do not need to adjust them.

Do you always shoot in the same direction, too? If not wouldn’t you need to adjust them anyway?

[Chronos]

Could we have a cite for military snipers ever going for headshots? Or that a headshot would have any significant tactical advantage over a mere mortal wound torso shot? Or that a headshot would somehow not give away your position?

[Xema]

Other problems with the linked article:

@Cecil

The Coriolis effect has a big effect on phenomena like hurricanes and other weather systems, a small effect on small objects.

Its effect isn’t related to an object’s size, but rather to the distance and direction it travels and its time of flight.

…they’ll also consult “cheat sheets” of bullet and rifle performance and their own log of prior results, called a DOPE (“data on personal equipment”) book.

Among serious shooters this is more often given as data on previous engagement (which makes more sense).

When possible, any shooter, whether professional or amateur, makes a few test shots on arriving at a new location and tweaks his or her sights accordingly. Mostly this is to correct for maladjustments due to jostling in transit and such, but it also compensates for the Coriolis effect

Coriolis effects vary with the direction of the shot, so (as squidfood notes) test shot results can’t properly deal with this effect unless you plan to shoot in just one direction,

As we’ve seen, vertical deflection depends on, and can vary considerably according to, what direction you’re shooting. Nonetheless, none of the amateur shooters we heard from worried much about it, and my guess is military snipers don’t either

They definitely do. Check out the PDA software sold by this company - with most sales going to the military. (On the displayed screen, look for the “Cor” label.)

[Lare]

@aerophex

(snip) thankfully I always shoot in CO so I do not need to adjust them. Military snipers traveling the world will adjust their sights accordingly.

Did anyone else first think that the shooter was firing in an atmosphere of carbon monoxide and think “WTF?”

I now take it to mean “Colorado” but how does only shooting in Colorado change anything unless the shooter IS always shooting in the same direction? Wouldn’t the effects have to be compensated for anyway?

[John_W.Kennedy]

As a general rule, if you drop someone with a head shot, he can’t fire his own weapon. In some situations (especially dealing with a hostage taker), this can be critical.

On the other hand, since it will kill him, you can’t take advantage of the “Kill one, take out one; wound one, take out two” principle.

As to the CO question, I suppose what he means is that he’s got some adjustment that goes from 0 to 359 allowing for direction, but that moving to some point sufficiently distant from Colorado would require recalibrating the adjustment, possibly in a difficult, nonlinear way.