Long Range Rifle/Scope/PRS question(s)

I am always curious about how all of the variables affect a bullet in flight. Of course consistency is key to everything and in my experience, wind is the hardest one to control. You can't really control it, you have to read it :)

I had an experience last year where I was shooting at targets alongside the edge of a cliff. When I got out to the 1000 yard target, things got really strange. My first shot was a MIL high at that distance. At first I thought I misread my reticle and took another shot after verifying. Same result. It turns out that at that distance, the terrain had changed substantially, and the wind was coming up the side of the canyon and giving my bullet at least 1 MIL of lift, or what would probably be 1-2 grains difference in powder.
 
@MarshallDodge - no doubt. I’m really not very good at windwork, but I’ve learned to consider wind-flow over terrain and around features like the fluid system it is. We can only see the wind at certain positions, and can only measure it (short of calibrated wind flags) at our shooting position. So I try to be mindful to correct my readings by interpreting how the wind traveled to reach my position, and equally, consider what wind the bullet will touch on the way to the target. Whether it’s thermal flow up or down terrain faces, wind lift from wind compressing up a face, higher speeds from sailing over valleys or shooting off of cliffs and exposing to higher altitude air speeds than the shooting position, eddy currents swirling, it’s all of those little details that separate shooters from newbies to elites. My engineer-brain does a pretty good job at identifying flow patterns - relative direction and speed changes - if I can figure out the inbound wind flow and if I can see the terrain features... AND if I remember to be mindful of all of the above for every. shot. I. take...

I know those tricky winds have been a huge boost for me at some matches. Especially a night match I shot last fall, where we couldn’t see any field indicators. We shot from a ridge at another ridge. The wind we felt and could measure at our location wasn’t representative at all of the wind which was coursing down and across the valley between us. Lots of folks missed shots because they believed what they felt, and what their kestrel read.
 
So true about the Kestrel readings. The Kestrel gives a lot of information but it will only make things worse if you don't understand what you are seeing.

There is also the wind along the ground compared to 10 or 20 feet off the ground where your bullet will be passing on your way to the target.

It is one reason I like to shoot my 223 for practice, wind has a greater influence on the bullet. It helps me to learn the terrain and other influences.
 
@MarshallDodge

I’m still learning how to read the wind and I don’t know if the lesson ever ends

There are nuances to every discipline so take what I’m going to say into account as it relates to F Class

I’ve been fortunate to get some advice on wind reading from a few current and past record holders in high power and I’ll pass along some of what they have shown me.

The more you shoot in varying conditions the more you will start figure out you hold offs. I know that sounds trite but there will be a point where your wind call based on the mirage nets the desired result, the light goes on, and you’ll know how to handle the next shot in similar conditions

High Power doesn’t allow wind reading devices like a Kestrel so this will be geared toward the mirage.

Pick a condition that you’re scoring in and shoot that condition. In other words, be patient. If the wind is fishtailing and you’re getting hits (or 10’s and X’s) with a right to left wind, then don’t shoot when it switches left to right, even if you think you have the hold off figured out. Having said that, time is a factor and you may have to take a shot in less than optimal conditions.

Don’t be afraid to shoot in “the boil”. When the mirage is boiling it’s usually because the wind is changing direction or it’s coming from your 12 or 6. If you can find a period of consistency it’s a great opportunity to score, if you have a hold off for that condition.

I had the high score and won my last F Class match against some very accomplished shooters by shooting predominantly in the boil and knowing my hold off for a 2 o’clock wind and being patient enough to wait for those conditions
 
When shooting Benchrest at 100/200 it was often identifying the prevailing condition and knowing where to hold. That gives you more time, and if it is a good condition to shoot in, then bingo. But sometimes the prevailing condition sucks to shoot in and you hope to get times during the seven minutes where the condition is good to shoot in, then try to finish a group in it, even if you have to stop when the condition degrades, and then start again later when it comes back around. Sure can be nerve wracking waiting for it when you need to finish a group and are running out of time, or you are out of time and have to finish a group under a different, not so great, condition. Playing in the different conditions a little during the day can help if you get stuck shooting in a less preferred one.

I am very new to long distance wind reading.
 
I used the Curtis Custom action wrench for the first time yesterday. Put Jeff's pre-fit 6GT barrel on his Curtis action. Forgot to take a pic of the job. Sigh. I do have one of the wrench. Used 90 Ft Lbs
 

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I’m interested in seeing how the 6GT performs. My .308 will need a barrel soon (3,500 through it). The only thing standing in the way of it being a ready made PRS rifle is the caliber and I have a Bartlein MTU contour .243 barrel sitting at Short Acton Customs waiting for duty
 
I don’t get it. What is that chart trying to say?

It shows extra/less drop for head or tail winds, plus the Magnus force for cross winds, so a left-to-right wind pushes both right and down, not just right. The numbers in the S shape of the middle are the POI’s relative to a Center POA from 12hr clock source of the wind. If we hold center on a 9 o’clock wind, bullet gets pushed right and down. Whereas a 3 o’clock wind pushes left and up.

As to it’s validity - I know I have fired in head winds strong enough to push me down, and tails strong enough to lift me. Accounting for a little spin drift at 1,000 never hurts. But I can’t say I use this for PRS matches. Maybe I’m just not spinning my bullets fast enough to make a 1 o,clock near head wind cause my POI’s to rise instead of fall? Pretty sure my group size at 1400 is bigger than my magnus influence.
 
That chart gives a pretty good look at how wind moves bullets. In Benchrest some would just pic a condition and shoot only it, not caring what other wind directions do to the point of impact, but you can't always get the same condition, even in that 7 minute window, so knowing what the change in wind direction will do to the point of impact is beneficial. Of course we had a sighter target to shoot first, assuming we still had time, to see what a different condition is doing to the POI. In twitchy changing conditions sometimes we don't have time, or rounds, since we had 20 or less, uselessly 15 or less, rounds with us at the bench for that group, so we had better have a good idea of what a change will do.

In PRS or F Class, we don't have a sighter target, so a decent understanding of what a change in wind will do is helpful. It is more art that science, as we calculate it in our minds (Guess).

Back to Benchrest. Let's see, the flag at 25 is doing this, the flag at 50 is laying down, the flag at 85 is doing that, the flag at 125 is doing this, the flag at 175 .........and then you solve that little math problem in your head..........because you have two rounds left, three on target, and 45 seconds to finish your group. Which is often times a self inflicted problem, but sometimes the condition you have been shooting all day just doesn't show up for you. . :)
 
Self-realization and credit where it’s due: Thinking more about this thread this morning (in the context of currently recreating a new data book for a new barrel for this PRS season), realized I do use this graphic more than I expected or gave credit. Religiously, albeit nearly subconsciously.

I’ve had this graphic in my data books for over 20yrs that I recall, same as I have mirage angle graphics and the fractional value clock, but I haven’t given it much thought - and certainly haven’t given it enough credit; as I said above, I didn’t realize I was using it at all until I was dry fire practicing this morning, thinking of this thread.

Largely, I have always considered the “net wind call” to be the challenge. My experience/process is largely as @Walkalong described in his last paragraph above: I observe indicators throughout the field and try to determine what I call a “net wind call.” This is the hard part for me, compiling all of the info into ONE number quickly and hopefully accurately, which then yields a simple table or calculator output for hold/correction.

THAT is the number on which I focus. I work from there as I observe the results downrange, but THAT is the number in my head for wind hold, THAT is the number I write on my data card for a stage.

But from there, I make a “scribble” correction with the crosshair which is consistent with this graphic - which I didn’t really realize until this morning. I don’t really think as much about it as I do my wind call and resulting data point, but I have this subconscious voice/second-guess/nagging-nudge right before the break. I don’t move off of my data, don’t dial any extra on or off, and I don’t calculate any value for it or think “hold 1/10th more,” I just edge my crosshair-scribble a little toward the indicated direction, kind of like coloring outside the lines just a little.
 
I don’t move off of my data, don’t dial any extra on or off, and I don’t calculate any value for it or think “hold 1/10th more,” I just edge my crosshair-scribble a little toward the indicated direction, kind of like coloring outside the lines just a little.
Agreed. And it is often times gut driven as much as mind driven. You don't concentrate on it so much, just let the subconscious/gut take over. Believe in your instincts, don't second guess, just go for it.
 
Believe in your instincts, don't second guess, just go for it.

Yeah, I did that at a match a couple of months ago on a pretty stiff full value right to left. Thought I had the right hold, felt confident, broke the shot but the wind was better than me on that one (and a few other). Wind pushed the bullet out of the 10 and I barley held the 9, but I learned from it. Namely, when the leaves are blowing across the range and never touching the ground DON'T SHOOT. You aren't good enough yet. lol!
 
Yea, it doesn't always work out, but like you say, it stores in our computer and hopefully makes us better in the long run.
 
I said this before a large number of posts back, but bears repeating: In terms of info on rifles, barrels, scopes and associated accessories as they are used in competition shooting, this thread is the bomb....

Thanks all,

Russellc
 
walkalong, now that we're at 40 pages we almost need a table of contents. you should add some links to the OP like bookmarks, to the pages of this thread that start discussion on the new guns as you go from havok to impact/foundation, etc, and a couple of the other interesting discussions we've had along the way.
 
I said this before a large number of posts back, but bears repeating: In terms of info on rifles, barrels, scopes and associated accessories as they are used in competition shooting, this thread is the bomb....

Thanks all,

Russellc

walkalong, now that we're at 40 pages we almost need a table of contents. you should add some links to the OP like bookmarks, to the pages of this thread that start discussion on the new guns as you go from havok to impact/foundation, etc, and a couple of the other interesting discussions we've had along the way.

After @RussellC’s comment this wknd, I spent the last couple days (between wresting tournaments) re-reading this thread in its entirety. A ToC would be incredibly valuable.

@taliv & @Walkalong - I’d be happy to go back through this wk and create the post, but it’s up to you Mods to insert it at the beginning once that’s done. There’s a LOT of discussion here on a LOT of topics.

Admittedly - I THOUGHT we had a series of posts in here about PRS stage designs and obstacles, but I realized after re-reading the thread that we made that its own post. There might be a few other threads like that, or the 6 GT thread which have value as “related links” in the ToC post for this thread.
 
An index for topics, and links to pertinent threads, could be easily added to the first post.

An admin might be able to fool the calendar and make a new post go to page one.
 
that would be awesome varmint, thanks for offering

maybe we should make the post separate and sticky it in competition forum, and add the TOC to the OP in this one
 
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