OzFclass

Hi All,

I posted a question yesterday that I ended up deleting as I think It was unclear and I left it too open. I'll try again.

How do the most successful F-class shooters, make preparation and actually (not in theory) apply their advanced external ballistic knowledge, pre shoot?

Do you have a system of running through the shoots conditions and making alterations other than my simplistic "I'm at 600 yards, that's 12 minutes on my 100y zero".

For example sake only:
a. Do you guys take a moment pre-event to consider the range direction and coriolis and adjust your "local club zero" accordingly.

b. Do you take a moment pre-range to consider the current temperature v's your "zeroed temperature" and make that extra 1 moa adjustment.

c. Do you guys actually record temperatures and conditions of the days and events that you shoot?

d. If you start a shoot in a heavy 9 o'clock wind, will you alter your elevation before the first sighter?

Is it enough to have an understanding of external ballistics and why change happens in and between shoots. Simply making corrections from the first sighter. Or does that knowledge have to be applied pre-shoot to be consistently at the top when shooting at many different locations.

I am still learning a lot of this stuff only being new back to the sport. I have shot a fair bit in the past year and have been picking up quite a lot from experienced shooters and from what I can see and from what I've done, the best way to do it is to keep a record of what you are doing, when you are doing it and where. That give you a good starting point for the next time you shoot a certain distance or on a certain range. I find my zeros are fairly consistent range to range shooting the same distance give or take, and I can get into the 4 ring fairly comfortably at any distance using the settings I have recorded. The better shooters with more experience and better knowledge of their gear and loads can get in the 6 ring with their first sighter. More time on the range working on setting up your gear and an accurate log of your zeros and wind conditions will go a long way to getting you closer to the x ring with that first sighter. Don't know how helpful this has been, but it's how I've gone about working through the things you have asked about.

I think the only thing wrong with this question is that most of our best shooters and guys that we look up to like Alan, Cameron, Mark, Dave and Pete erc are very modest to a fault and unfortunately may not comment in a public forum as they may feel it's bragging of sorts?!


Maybe to start the ball rolling i personal don't get overly technical as from what I've seen every range seems to be different and for example don't always represent a TRUE 700m. It may actually be 715m and another range may be 695m so it's hard to beat actually putting rounds down range.

lower light SA your elevation can be hugely influenced by wind angles and different levels of mirage. Other ranges can have abnormalities that are too complex to calculate due to trees, hills, gullies or creeks for instance and may over rule some of the more subtle effects of spin drift etc.

I look up the local weather and back through my load data and try to find a balance of how I think a barrel will perform at the event location. Personal when developing a barrel I try and find a load/ node that is very wide. I may sacrifice a very very small amount of accuracy but as a maintenance coordinator I'm a bit OCD about reliability . . . . .OK more than just a bit OCD

Thanks BATattack. When it comes to handloading, tuning, equipment maintenance and setup I feel that I do more than I need to so that I know everything there has it's best chance beyond a doubt. I also try and pick the middle of a node to allow atmospheric variation.

I enjoy reading books on handloading, strategy, ballistics, long range shooting and about other disciplines too.

The reason for my question, is that as hard as I try to remember concepts I find that especially in the heat of the moment and leading up to, I just don't think about most of them. And there are so many. I watch the wind for a while before I shoot (if possible), decide which strategy may suit the conditions best, wind on my known elevation, guestimate my hold off, take the first sighter and away I go.

It got me thinking, am I wasting opportunity by not thinking about all the extras during my preperation. Am I being lazy and preparing differently to all the successfull guys that are consistently seen in the top 10, 15 or 20.

Don't get me wrong, I know atthe end of the day it comes down to wind reading and shot execution, but I'm just focusing on what should and is being done with all that extra external ballistic info that most of us fill our heads with.

I think you just answered your own question to an extent. You need to be 100% confident and proficient in the basics before bringing more advanced things into your bubble. Worrying about other small details might distract you from something that could be a much larger detriment . . . . Forgotten bolt, wrong scope setting etc. If you can't do it under pressure then leave it out of your system until you feel confident with it.

I'm a lot like that and try to do the basics as best as possible. Build a reliable rifle with accurate log books and a good maintenance program that is designed to minimize a failure or a incorrect scope setting etc. Get that down 100% and your gonna be tough to beat!!

Just bring 1 new thing in at a time.

There is no magic bullet.
Mike.

Denis,

I use a good ballistics program as the basis for most shoots, and record a large number of details about each shoot. However, things like Coriolis I never think about. If you want a deadly accurate wind zero for team shooting, or if your individual wind reading method relies heavily on having a good zero, then you could justify going to some lengths. But I've seen some shooters lose points because they put too much emphasis on their "good" wind zero, and ignore what is actually happening to their shots! It would actually be more important for tactical class and the like, who need good "cold barrel" accuracy, to have good handle on the various ballistic effects. We have the luxury of sighters.

However there are some of these effects that it is worthwhile being aware of, because they can change from shot to shot. If the wind is "flopping over" from one side to the other, you can get the "right wind raises" effect. I say you can get it, because in some situations, it doesn't seem to happen, and its severity varies depending on the headwind component of the wind, and the side slope of the range. Even with that, I don't do any maths, but just take a guess from experience and observe the success (or otherwise) of the shot, and learn from it.

So in summary, for team shooting where good zeros are critical, the coach could be justified in getting quite technical about things. But for the individual shooter, probably not necessary to go to great lengths. Its better to have a general knowledge of what these effects can do, and have a flexible approach to what is happening on the target e.g. at 1000 yards, if your group moves for no apparent reason, its probably because of one of these damned effects .

I'm sure there will different opinions!

Alan

Thanks Alan, that's a great answer. Exactly the kind of personal experience/protocol I was hoping to hear.

Hopefully we'll see more posts come through from others.

The topic may seem insignificant but the insight that you've just shared is very helpful.

I'm far from meticulous about doing it but I try to record the density altitude along with the elevation setting. It's helpful in a multi-day shoot where you might shoot a range on a hot afternoon and come back to the same range next morning when it's cooler. Not a matter of life and death but if your sighters are in then it's two less chances for something to go wrong at the end.

Barry

Jbm ballistic app on my iPhone , a Leica range finder , an anometer and a lot of luck. Read b litz about corialis and spindrift. I try to treat my first shot like I'm hunting and try and make it count as much as possible . Regards Graham .

plumbs7 wrote:Jbm ballistic app on my iPhone , a Leica range finder , an anometer and a lot of luck. Read b litz about corialis and spindrift. Regards

Yep, I get all that GS, but do you and how do you, yourself, actually apply all that information to your usual range zeros, in preparation for a comp. Or do you feel that collecting the information for interest sake is enough for you?

Cheers,

DenisA wrote: but do you and how do you, yourself, actually apply all that information to your usual range zeros, in preparation for a comp.

You addressed your question to Graham but I'll rudely butt in and give you an example of what I do. Say we're finishing Day 1 at 1200yds on a hot afternoon and the density altitude is 4900ft. I put this in my book along with the elevation setting. We're starting at 1200 on Day 2 and working down. It's clear overnight and freezing in the morning - DA 1000ft. I consult my Accuracy 1st Whiz Wheel and see that in these conditions I'll need an extra 2.7 minutes of elevation so adjust my scope accordingly.

Barry

For the longs I correct for temperature and pressure from my zero.

With regards to the effects of coriolis and spin drift. Have a go at detecting it.
I have done tests to try and detect their effects including reverse direction testing at distances beyond 1200 yards. Its an interesting exercise and a bit of fun. You can read about all this stuff but its only when you actually go out and look for it that you can appreciate what effect (or lack of) is taking place.

It is very difficult to detect their effect but it is possible if you plan it out properly. You need perfect conditions and the rifle needs to be perfectly level.

A rifle being off level can have quite an effect. Next time you are shooting at 1000 yards in good conditions and have the opportunity to fire a couple of test shots. Cant the rifle a couple of degrees off level and see where the next shot lands.

The truth is the range prep is all very simple. Before the advent of ballistic programs we didn’t know what happened in the bullet’s flight from mound to target unless you were a ballistician or had a good mentor like Percy Pavey who did know, applied his knowledge and could pull a good shot. He also thought outside the box and in heavy mirage, he once told me he aimed at a rubbish bin up close he could see and adjusted his sights to hit the target by calculating the minutes of angle in his head for the adjustment based on knowledge of his zero. That always stuck in my head.

There are few Percys about these days. So the secret to all this, is observation and how fast your brain ticks over. Prior preparation prevents piss poor performance.

Let’s stick to the essence.
Set your wind zero up short, about 140 yards using a plumb bob or level to for the alignment of your zero target.

If you zero in a northerly or southerly direction you avoid the elevation effects of Coriolis.

If you shoot at a zero target, set the target 1.5m above the ground to avoid mirage distortion. Its best to raise your shooting bench, so the angle to the target is no more than 5 degrees which is a common angle from mound to target on many ranges based on military specs.

Lets assume you have a pet load based where you recorded the density altitude. If not, the temperature. Don’t worry about humidity. That only applies for practical purposes based on mirage and apparent aiming mark shifts discussed later. You can use that as a base for changing your elevation having used your ballistic program to assess the conditions at your competition venue even if you don’t adjust your load.

Don’t worry about Coriolis effects either because that won’t change on the day. It only changes by location. Check this with a good ballistic program to see if the differences are marginal from your zero location to your competition venue. Pre-set if significant.

Like Coriolis, once set for the home range you never have to re-visit it, spin drift is an integral part of your zero and increases with distance. Make sure you set your ballistic program to Southern Hemisphere. In the old days, we set windage zero at 600 yards ½ left and 1 minute left at 1000 thousand because that’s what we were told for 7.62mm for a zero wind condition. Today, I would input all the factors into my ballistic program and go with that. Whatever you do, don’t cant your sight to accommodate the drift like some did in the old days with iron sights. That was wrong. Don’t worry about the Magnus force effect in lateral movement as this factor is small and is subtracted from the lateral spin drift movement. It is splitting hairs and a ballistician sees the effects in bullet yaw and overtuning moments of the Magnus Force. We also know some of the vertical damps with long range and the vertical ballistic jump is greater up short.

Look up the forecast for the days shoot. The biggest influence on the atmospheric density is the temperature, so stick with that. You may adjust your charge, assuming its an afternoon shoot for the velocity tune. This can be done with programs like Quickload, but better still from records of velocity as temperature changes in variations of 10 degrees F. I simplify this with the use of a tuner which I have pretested to match the charge variables which may be in the order of .3 to .6 grain. Or you may have a broad nodal tune to accommodate conditions.

On the day

Most Fclass shooters rely on shooting fast, and high bc projectiles to beat the wind and sighters to get them on the plate. But they get caught and may drop a point or their centre count drops enough for others to sneak the prize who have done their homework.

My take on the major problem in difficult fishtales is separating mirage horizontal and vertical with the horizontal and vertical deflection of wind on the spinning bullet. Assuming the terrain is flat and open; and vertical wind shear and angular alignment of the scope with the bore have been discounted, sometimes the apparent aiming mark shift due to humidity can counter the deflection of weather or exacerbate it. This is what is confusing, not the ballistics. Its like two steps forward and one step back. Like Alan said, the general context is ok. For mirage, as the boil drifts it may be in the order of ¼ point and another ¼ as it runs, moving down on your sight or in ½ point moves if the mirage is heavy. As the apparent aiming mark comes down closer to actual, you have to come back on the windage as the apparent aiming mark shifts outwards from the wind direction, but maybe in ½ point steps. The effects of mirage are seen in densities of light, medium and heavy the changes and are in the order of zero to 1 ½ points. (This explains those shots that are way out sometimes when we really can’t see it in the flags).

Then you make the wind deflection allowance laterally based on typical mirage; and if you know the right wind raises pattern and the left wind lowers pattern, you can implement this as well. For instance, say you have come down for the mirage as it runs fast with a left wind, you will also come up as left wind lowers. Conversely as you come down with a fast mirage run with a right wind, you will have to come down further as right wind raises. I tend to only use mirage for wind deflection with fishtales and am aware it reflects wind conditions in the lower part of the range. So sometimes it does not represent the true wind condition for the whole range. But the apparent aiming mark element of mirage is true for the whole range. I tend to use flags for cross wind evaluation, but I know mirage is more responsive to change than a flag and it is more to do with the apparent aiming mark shift.

This needs to be a separate topic for discussion with illustrations. However if Peter Smith could add the effects of mirage movement and apparent aiming mark shift to his free ballistic program which already covers vertical wind deflection, you could practice that too. You will sacrifice score even with sighters, in these conditions if you don’t know where your zero is laterally and vertically. Its not a question of whether mirage is stronger or weaker from one side or the other. Its a calculation based on experience. If you discover the movements during your shoot, its already too late unless you just catch it.

There is nothing better for confidence when your sighters hit the spot and it follows, the less time you spend on the mound, the less chance you have being done by the conditions. If you are wise and confident in your zero, you can use your sighters to shoot on the extremes of a condition, say a boil or a run and use that to your advantage for the rest of the shoot.

As our shooting population ages, and I know from brain damage from tumour removal, your short term memory suffers. “Now where was that zero based on my sighters?” But the thing that doesn’t diminish at the same rate is the ability to see what’s happening and put two and two together albeit at a slower pace. So the secret here as you age is to know your zero, apply the apparent aiming mark shift and wind allowances and time your shot for the condition if you can.

If there are terrain or local conditions are problematic, a true zero will sort out what the condition was worth to put in your record to re-visit.

Finally, be aware that the barrel takes a few shots to establish elevation during a shoot. So your initial sighters may not indicate a true mirage elevation.

All of this info is fantastic! Thanks guys, I hope it keep coming.

David, your knowledge and contribution is always awe inspiring regardless of the topic. It seems that what you don't know about everything shooting, hasn't been written and a lot of what you do know, hasn't been written..... ..... always appreciate your views and find your writing style very easy to follow being the layman that I am.
Of that post, one part that really grabs me (aside from temperature) is the aiming mark shift with mirage. I never consider that during a shoot and easily could. I need to keep working with this and understand it on the range.

Norm and Barry, it seems to be a common theme as you've suggested that temp and pressure are the most important to factor in during preparation. I'll start using a ballistics program pre-shoot to try and hone that first sighter a little, especially if there's going to be a significant error.

Certainly seems like I'm lacking a lot of prep (and knowledge) compared to others.

Thanks guys, all the input is very helpful.