F-Class Team Belmont 2015

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williada
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Re: F-Class Team Belmont 2015

#16 Postby williada » Thu Aug 20, 2015 5:59 pm

Absolutely Tony. The spindrift compounds it both in elevation and lateral movement - left lowering and right raising as well. It also feels like the left pushes harder. Lowell's higher velocity tells us a lot and confirms my thinking for Belmont with regard to the laminar flow.

Without taking anything away from Lowell's brilliant performance over every range, his load appears to be punching through at 1000 with a tight node to boot.

Was his position on the mounds outside the what is deemed a bad position on the range by the locals for 1000 and was the weather for him more moderate than your circumstance, Tony? I am just trying to establish where the turbulence sits at Belmont.

If you can find out what speed your neighbour was running at and if they had a top score while you did not, you may find your go to node was too low in velocity terms to punch through the turbulence. This would be another bit of supporting evidence.

I think we have found the answer with your experience at the meeting with your comments to date anyway Tony.

I forgot to add. The most stable wind is a right crosswind. You really only have to concentrate on wind strength here and you can easily track the right raising effect and make adjustments accordingly. Also, the stacking of the laminar flow humps created by successive high mounds largely dissipates with a crosswind as the wind is not blowing over them but along them. The turbulence increases as the wind moves to the front or rear. If the flags are not at a respectable trajectory height, they can not tell you what's happening unless you have local knowledge and time your shot for the rhythm of conditions either. If there is no mirage it is harder again to read conditions.

Sometimes between the high mounds, fluctuating winds can cause a pulse in that the air density just above mound height raising and lowering. If you have insufficient velocity, your lateral comes into play before the bullet finds clear air at long range well above the mounds. If you shoot Sydney, that would not be an issue, but its hard to read flags beneath you. It seems there are hurdles to jump everywhere you go.

If the wind is sufficiently strong at Belmont, I could also imagine dead spots created by the turbulence could exist. At long range you can hit what seems to be air pockets created in the troughs between the mounds or general terrain. So the lift factor on your bullet could fail at times and sometimes the Magnus force with inducing spindrift can be reduced unless a higher velocity assists you, so it has you scratching your head for zero and again lateral shots occur because your decision making becomes blurred. Remember of course, one a bullet deviates up close there is no magical wind to blow it back on course. David.

DannyS
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Re: F-Class Team Belmont 2015

#17 Postby DannyS » Thu Aug 20, 2015 8:58 pm

David, I always enjoy reading your posts and trying to get my head around the knowledge you have, but I really like the last sentence in your previous post, ie once you have sent the bullet on its way, you can't change it.

Cheers
Danny
You might as well be yourself, everyone else is already taken.

williada
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Re: F-Class Team Belmont 2015

#18 Postby williada » Thu Aug 20, 2015 11:57 pm

Cheers, Danny.

I was not game to mention the additional role of the Magnus force and the role it plays with the centre of pressure and centre of gravity of the projectile and how that relates to projectile stability in such conditions. I don't think fast in the armchair. That's an ability on the mound I have lost. But hopefully new shooters can pick up reasons for why things happen. They are not acts of God because there is a reason for everything. It just takes time to figure it out after a lot of stuff ups trying to find the answer.

Maybe Aaron could chime in with regard to a closer look at bullets. David.

DenisA
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Re: F-Class Team Belmont 2015

#19 Postby DenisA » Fri Aug 21, 2015 9:38 am

G'day David, thanks for your very interesting explanations.

I feel like I have regularly seen the results of what you've described though I haven't had an explanation other than "I guess they're too slow and start to yaw!?"

My .284W is the culprit. To get better brass life I've been running it at 2730fps with 180VLD's. It's accurate and holds x ring vert from 300 to 1000 when shot in consistent conditions. When conditions are volatile, even though I'll pick a single condition to shoot in, the vertical opens up enough to just loose points. I suspect the overall group may actually open, though its hard not to point the finger at yourself when horizontal inaccuracies appear in volatile conditions even if your trying to shoot one condition.

Regularly when this happens, other shooters in the same conditions running 180 Hybrids or VLD's at 2820 to 2960 will easily hold less than x ring vert.

For this reason, I consider my .284W to be my club gun.

I've developed a 300wsm 185gn Jug load at 2920fps. Though they definitely are moved by the wind more than the 7mm's, have much lower BC and big lobby trajectory, they hold sensational vert and are very accurate in all conditions.

This is where your point about bullet radius and torque struck a note with me.

BRETT B
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Re: F-Class Team Belmont 2015

#20 Postby BRETT B » Fri Aug 21, 2015 3:20 pm

Very interesting read . after coaching for 2 days solid with our F Open Team I found myself battling Vert with my 7mm ( 180VLD @ 2890) on different parts of the range at different times of the day. I am still new to the big 7mm bullet and tuning them so after not a very good Queens performance I bought out my 260AI ( 140VLD @ 2980) for the last day and probably shot the best waterline I had all week at 900 and 1000.
BRETT BUNYAN F CLASS OPEN SHOOTER W.A.

williada
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Re: F-Class Team Belmont 2015

#21 Postby williada » Fri Aug 21, 2015 4:59 pm

Thanks guys, I just thought I would throw the following in to finish up and this includes the Queens.

If the rifle is not in tune, then you are behind the eight ball. Raven's six P's are spot on. My discussion is primarily focussed on the frontal winds Tony had experienced with fully tuned rigs for the Queens. Yes, you are going to cop a belting with a wind change as it moves to the front if you have not got sufficient time to wait it out and the slope of the land can funnel this effect making things worse.

However, for the purpose of the discussion the evidence to date suggests air density was an issue. The air density when high scores were shot was less dense and were temperature induced in one session from what I can deduce, then scores fell away in another with cooler denser air. Here is a situation where we might fall off the node, so we can tune for a wide node, use a tuner or use different charges and not be too worried about high end nodes using your regular setup and take your place with everyone else battling away.

The situation is a bit more complex if there is a frontal or rear wind and the air mass travels over high mounds. Firstly, the air is compressed over the mounds and other layers sit on top. There will be spots with calmer eddies, due to terrain, but if you are shooting on the higher mound, then the air above is likely to be compressed and you also have to consider where your position fits within the general slope of the terrain you are shooting on.

If you look at pressure, like isobars that closely form in the weather reports you will note the ones close together denote faster wind speed.

Once a bullet deviates it cannot be brought back on course. These denser airs at the firing point have the greatest effect and they are lower than normal. So the down range flags which usually coincide with your high point trajectory where winds normally run faster mean that closer flags are the more important ones unless there is a gully running through. The other problem is if the flags are too high up close, flags won’t register their true value for the bullet trajectory. So your wind calculation can be misjudged.

Secondly, there is a deviation laterally of the projectile simply because the air is running fastest at the most vulnerable part of its flight. So if you are under gunned, you will get carted sideways if you don’t happen to hit the turbulent interface of different air densities. This largely depends on your ally in the total landscape.

Thirdly, turbulence is struck when the bullet travels on an angle through the denser air and hits the less dense air in its high trajectory to 1000.

It is this third area where a slightly higher velocity is needed to assist the VLD’s because they are inclined re-orient quickly with the air flow. If it is turbulent you could imagine these projectiles twitching a bit. The more data we get the more we will know. This stuff is not so much a problem on flat ranges or where mounds are low.

What gives you the minimum velocity maybe a low end node for a .280 AI or a 7mm SAUM or a mid node for a .284 but a very low end node for a .284 maybe struggling? If you have a high end node, you are laughing and who wouldn’t burn a barrel just to win a Queens. After all, the trend has been to 7mm or big calibers to beat the weather at long range because you can bet on the long competition the sh**t will hit the fan. As everyone runs with the same gear we have to look a bit deeper to get the edge. It’s up to the individual if they want to plan for using a theory called the second best. Probably the only thing up your sleeve with calibers shy of 7mm is velocity.

I don’t think the third phenomenon is a tune thing. Because we know that bullets with a greater radius are harder to re-orientate when encountering a different flow direction. This is different for denser faster air where the mounds or terrain are not interfering and so the air density is relatively constant for the flight path. Any problems encountered here are tune problems. It’s a simple fix for the mound impediment if those circumstances present. I have seen this in the past at Bendigo with rear fishtails in particular. David. :D

RAVEN
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Re: F-Class Team Belmont 2015

#22 Postby RAVEN » Fri Aug 21, 2015 7:56 pm

Dave at LL here in SA we get a lot of fishtail conditions and yes it will push the impact point up or down depending on the direction due to bullet spin the range is every flat therefore this force on the projectile is consistent.

I had this discussion with Dave Mac (I think) and I stated that it was a brave coach that would adjust for elevation on a given condition like you are discussing.

I think that what you’re discussing has and exaggerated effect at the Belmont range because of the hole particularly with fish-tale conditions.
In our team practice at 1000yad line I had the wind gusting a lot stronger into our face at one point and made my shooter(Adam from memory) take a shot guess what the bullet struck the target at 6.30 in the 4 ring would I now hold over 1 MOA probably not! Best to just not shoot on that condition.

RB :)

williada
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Re: F-Class Team Belmont 2015

#23 Postby williada » Fri Aug 21, 2015 8:58 pm

Richard, thanks for your observations and indeed my reference was specifically directed to places like Belmont where these effects are exaggerated where Tony was at a loss to explain his shots. Why was the purpose, not the solution.

It’s true, that is hard to make the elevation calculations but you can under normal circumstances. Rather than try to hand out charts describing these allowances, I tried to give a simple solution which would give you a measure of improved performance by way of velocity or projectile radius.

I completely agree, the right strategy in a team shoot where you have time to wait a patch out, is the right strategy. Being a bit long in the tooth, when I was a member of a few state teams in the 1970’s, it was part of the coaches armoury if needed for another shooter to fire a sighter to enable the coach to get a handle on conditions. I also remember vividly, Brian Titcombe, a mentor of mine was the sacrificial lamb for the Australian Team. When it counted he shot for the benefit of others between shooters to verify calculations which were usually pretty right anyway.

I can also say, that as a coach of quite a few successful teams at Williamstown ranging from pennants to Victorian Teams Championships, shooters will attest to the elevation changes made as they related to wind strength. At the time, everyone had a copy of Jim Sweets book which emphasized that very point. As did Percy Pavey, who was always willing to quietly pass on tips every week. We had the likes of competent mathematicians like Harold Ryan (who also did a lot of mirage research with cross hairs in a telescope that DaveMc has recently researched) do such things for elevation allowances. Tony has in his hands a bit of information in this regard, but he is not allowed to hand it out.

You have to accept for tough conditions you play the percentages and get the fear of losing out of your head so you can perform at your best. This is where the 6 p’s come in and team zeros have to be perfect for successive ranges.


I have to say the weekly competition amongst several hundred shooters at Williamstown in those days was hard and uncompromising and you had to wring out every nuance out of your kit that you could. It was not uncommon for a Queens series to have 600 shooters in those days.

This takes nothing away from the top scope shooters performances but he who dares wins.

williada
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Re: F-Class Team Belmont 2015

#24 Postby williada » Sat Aug 22, 2015 10:16 am

Hopefully in drawing this to a close, coaches or prospective master coaches should be using Peter Smith's wind simulation program to practice the mental arithmetic required for high level performance.

We are indeed blessed to have someone in Peter's case put it together. He has an emphasis on the spindrift calculation and you can proportion that calculation to suit your rifle by way of BC percentage you actually would use in normal conditions.

Could I also say, my wife has just commented and she is a TR shooter, about how much to move in elevation for the left wind lowers right wind raises for a normal range condition, not the extreme stuff where you have to hunt and peck. She says it is just a simple ratio if you know your wind. She's right, for instance it maybe you move 1 point in elevation for every 5 points of wind in TR in a big change. If you are using a scope the ratio allows you to scale things down and you may move for example 1 point for wind and tickle the elevation as an approximation with !/8 or a quarter up or down depending on your gear in a change for left or right wind to be thereabouts, instead of constantly following previous shots chasing the spotter. This is a pre-emptive strike. If you observe the top shots they actually make corrections for what they see, because they are so well drilled and confident while the target is in the pit.

Tony's info I slipped him is refined to match precise equipment and conditions so that's why I have generalised with the figures.

The point is we have many capable shooters who have loads of common sense who can be awakened to use this stuff that has been around for donkey's years and it has separated the champions from others consistently over time. If you practice it, you can get better at it. The key is to identify the problem and use the right tool to fix it. Of course the elevation calculation can be distorted by apparent aiming mark shifts. That's another level again for the master coach to consider. We are working on that too and its not for everyone's eyes.

Every young person today is expected to finish Year 12 maths. They are not daunted by the reality of its power. They are our future. Most older people are scared of computers, others embrace them. So why would people fear using the spindrift when it is a reality. Sure its complex and if you are told it works try it because seeing is believing. Its not all about getting the master tune, or BC will save you because we also know in turbulent conditions bullet shape and radius enter the mix.

So why should people have to wait to get into a high performing team to get hold of such knowledge. They should be practicing it in their youth so this stuff rolls off their lips, so they are relaxed about process in team shooting when they make the grade. I could imagine our future international teams being a tough act to beat if we have groomed competitors for years instead of losing the bright ones because they are insufficiently challenged.

Too much time in team practice is about sorting out people's gear. If you want to be in a team that stuff should have been sorted. Its development stuff, not practice stuff. The team practice should be about building team harmony to grease the wheels of communication processes for the big event to let the trigger puller do their job and the coaches do theirs. If gear stuffs up, have a spare rifle.

It would also mean, that the filters of age, finance etc would be less of a factor in team participation. Us older guys have lost our reflexes and visual acuity. Let those younger people or if you cut the mustard still, fill our teams with the confidence to relax with older guys who are coaching or mentoring who know their stuff to build better teams. Over time with the growth of FO, there will be more depth to choose a team from. At the moment participants skills are still developing for many. Its not age that is a barrier to development, its mindset, application and willingness to embrace realities. You never stop learning. David.


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