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PostPosted: Mon Dec 03, 2018 2:15 pm 
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Hallo Dale

Dale SH wrote:
Hello Wouter.

Yes I did read your writings about the caliber.

Would you please in your opinion clarify a few things for me:
Do you believe that the Creedmoor is not capable of 2800 fps with a 24 inch barrel because:

Nee Dale die 6.5 Creedmoor kan nie daai snelheid bereik met 140gr en poeiers wat brand soos IMR4350, S365, Reloader 19, XMR4350 ens nie. Hierdie stelling is gebasseer op herlaaihandlydings se maksimum snelhede vir die kaliber in die looplengte.

1. To achieve the above, the loads are genuinely over SAAMI MAX pressure or

Verseker. As jy QL herkalibreer met die maksimum snelhede dan sal jy vind dat jy naby 70 000psi moet hardloop om die snelhede te kry en dit verklaar te pragtig die ervaarde druktekens met goed soos gerekte primer pockets.

2. The original large primer pocket cases where never designed to handle the pressure at 58 to 60 psi presssure.

Nee glad nie die geval nie. Die doppe se basis konstruksie is presies dieselfde as die 260 Rem sin. As jy na daai einste herlaai handlydings gaan kyk sal jy sien dat die Creedmoor op gemiddeld 10-15ft/sek vinniger is as die 260 Rem en dit strook presies met wat ons weet van die Creedmoor wat meer beskikbare dopkapasiteit het as altwee gelaai is na dieselfde TPL en teen dieselfde drukvlakke. Daar is niks fout met die doppe se ontwerp nie, die druk is eenvoudig te hoog. Die smal primer pocket doppe hanteer druk net beter, maar die gevaar van hoe drukvlakke bly absoluut daar.

3. The stated SAAMI max presssure is optimistic and should never have been set that high considering that the parent case for the 6.5 Creedmoor is the 30BR which has a SAAMI max pressure of 58700 psi and the original large primer pocket case was never "strengthened" to accomodate the higher pressures ?

Nee die probleem le absoluut by die feit dat ons ver oor maksimum drukvlakke is as ons teen 2800ft/sek skiet met n 140gr koeel uit 24 duim lope. Ons het QL vertrou op sy voorgestelde drukvlakke wat verkeerd is. As jy die WF kalibreer met herlaai handlydings se data dan lyk n WF syfer van 0.65 meer in orde om werklike drukvlakke te voorspel. Dit doen nie veel aan die voorgestelde nodespoed voorspelling nie(barreltime) en verklaar hoekom mense baie keer so 10-20ft/sek vanaf die voorgestelde nodespoed hulle werklike nodes kry. Sover ek dit het is die Creedmoor gebasseer op die 30 TC wat weer op sy beurt gebasseer is op n verkorte 308 Win dop en ons weet dat die dopsontwerp glad nie n probleem het met 60 000psi drukvlakke nie. Die 30 BR se maksimum drukvlakke is ook 60 000psi so al is dit korrek(wat ek baie sterk betwyfel) sal dit ook nie n probleem wees nie.

Im keen to hear your thoughts.


Hoop dit help en klaar n paar aspekte op.

Groetnis
Wouter


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PostPosted: Mon Dec 03, 2018 3:12 pm 
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"en verklaar hoekom mense baie keer so 10-20ft/sek vanaf die voorgestelde nodespoed hulle werklike nodes kry" UITEINDELIK!!!

Wouter, my ervaring was as volg: Ek het ook 2800fps gejaag met 140gr koele uit 'n 24 duim loop. My Qload node by 2792 (hoër node) maar by daardie spoed het dit gelyk soos n scatter gun groepering. Ek waag dit toe effens vinniger en kry wat ek soek hier by 2830fps, maar 4 uit 10 primer brand gate in. Dit was met S365. Toe verander ek na N550 en kry wonderlike groepe by presies 2820fps met besonderse lae ES'e (<10). En toe na 4 lekker naweke met mooi groeperings verander alles negatief. Wat die rede is, weet ek nou nog nie, maar ek het die 140gr RDF's eenkant toe geskuif.

Toe lees ek hier wat jy gesê het oor die hoër as voorspelde druk en besluit basta met 2800fps. Ek wil jou werklik bedank vir daardie skrywe.

Maak toe loop mooi skoon en laai 10 x 140gr Customs om loop te fowl. Qload se node toe hier rondom 2690fps. Ek besluit dadelik om te laai vir 2720 (30fps vinniger). En whallah!!! Dis hoekom ek sê UITEINDELIK!!! Ek het toevallig net Sondag oggend vir JohanvB gesê dat ek van opinie is dat Qload en 6.5Creedmoor nie dieselfde taal praat nie en julle redenasies hierbo staaf dit eintlik mooi.

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PostPosted: Mon Dec 03, 2018 4:52 pm 
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Wout is daar nie n maklike manier wat mens onder op die web kan meet hoeveel die dop uit sit na hy geskiet is nie, as hy mos meer as X uit sit kan mens sien of hy te hard werk

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PostPosted: Mon Dec 03, 2018 5:19 pm 
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Some of the more innocent handloaders look at the figures in one of the numerous reloading manuals on the market and see a certain powder charge with a certain bullet weight in a given cartridge listed as MAXIMUM. Their reaction is shock, horror and they dive for cover. Evidently, they think that if 1/2gn. more powder is used than this MAXIMUM load the rifle will blow up with a frightful bang, rip the shooter into myriad ragged pieces and, scatter blood, flesh, bone fragments and hot bits of shrapnel all over the countryside.
Actually, things aren’t quite that extreme. In fact, a maximum load is a predicted maximum powder charge, and while it can be an overload, it’s not quite as dangerous as many reloaders imagine it to be. In recent years the people who compile reloading manuals have erred on the side of caution and reduced their maximum loads - something many handloaders have noticed and commented on. However, this was done for a perfectly good reason. Too many handloaders looked at the data, were impressed by the velocity of the maximum load and set out to work up from there. Of course, they struck trouble with excessive pressure right from the start. This was incentive enough to have maximum loads reduced slightly. If you were to check an old manual you are likely to find a reduction of at least 2 grains between the old and current maximum charges.

This doesn’t mean, however, that it’s safe to start with a maximum load when you commence working up data - you definitely should not! Maximum powder charges are listed as the likely level where you can expect your loads to top out. They are intended to give an indication of when to stop adding powder. Despite being slightly reduced, all maximum charges should be treated with respect and once you reach that point, you should proceed with the utmost caution, even if the fired cases and rifle don’t show any signs of excessive pressure.

Maximum loads are not carved in stone. They can’t be because of all the variables. Just how much powder can be used in a certain calibre with a particular bullet weight depends on a great many factors; the type of action, the make of case, the type of rifling, the rifling twist, the bore and groove diameter, the throat length of the chamber, the primer, the hardness of the bullet, the amount of bearing surface it has, and so on.

Some makes of cases are heavier, due to having thicker brass and hold less powder than others, hence they will show pressure signs quicker. At least one make of magnum primer designed especially for heavy charges of slow-to-ignite powder, increases pressure if used with smaller amounts of easily ignited powder.

Bullets with hard jackets and cores and considerable bearing surface can increase pressure by up to 8,000 p.s.i. Bullets that are seated out so that they are jammed into the lands at the “lede” raise pressures by about the same amount, enough to expand primer pockets and cause gas leaks. Bullets seated so deep that loading density is increased can raise pressure by about 2,000 p.s.i, but are not as critical as those jammed into the rifling.

Chambers with long throats cut so the bullet has to make a considerable jump before it engraves the rifling result in lower pressures - and also less velocity.

Always bear in mind that cartridge cases that are thicker, have less capacity, and will give the same pressure and velocity with less powder than another make of case which has more powder capacity and thinner brass.

Some actions are capable of handling more pressure than others. The brass case is the weak link, and actions that support the case with the steel of the chamber or the recessed bolt face clear up to the extractor groove will handle more pressure than actions that do not.

Actions that enclose the case with steel to the extractor groove are the Model 98 Mauser, the Ruger M77 MK II, Weatherby Mark V, the post 64-Model 70, the Dakota 76, and the Model 110 Savage. The Model 1903 Springfield, the Classic Model 70 and the 1917 Enfield all use a coned breech that leaves a little of the case sticking out. But with good modern brass, all of these actions are safe with pressures running up to 60,000 p.s.i as shown by the fact that they were used for thousands of hot 7mm and .30 calibre magnum rifles. The new Classic Winchester Model 70 is chambered for the Winchester Short Magnums which are loaded to mean pressures of about 63,000 p.s.i.

In this modern day and age, all the ammunition companies together with makers of bullets and cases and propellant powders have equipment for taking pressures and velocities. Most of them put out manuals containing data for handloaders. These manuals usually give such valuable details as the make of case, the make of primer, the make of the bullet, the length of the barrel, the pitch of the rifling, and the maximum cartridge overall length. They also list the maximum case length and the trim-to length.

Very few list any pressure data. Norma did years ago, but in any case it would be irrelevant because of all the variables that exist. It would be a fluke if their listed load produced the same pressure and velocity in your your rifle with different components to what the manual listed.

Another thing for the handloader to remember, is that if the load he settles on gives easy extraction and he can reload his cases from 10 to 30 times without primer pockets becoming enlarged, that load is safe in his rifle with the components he used.

On the other hand, if his cases are hard to extract and after three or four loadings he finds that primers slip into the primer pockets with little or no pressure, the load he is using is too hot no matter what the maximum is supposed to be. If he gets primer leaks or a blown primer, he has definitely exceeded the maximum charge for his rifle.

Load development a.k.a “working up a load” might be defined as the detailed execution of the planning of a handload for a specific purpose. This includes a fair amount of experimenting and testing to ensure that the load is safe. You should begin with a powder charge below the listed maximum and work step by step upwards until the desired specification for the projected load is achieved, or until it becomes obvious that it cannot be achieved safely with the selected components.

If the handloader has a micrometer, he should measure the solid head of his cartridges before and after firing and compare the measurements. On rimless cases, the reading is taken on the case head immediately forward of the extraction groove, and on belted cases the head forward of and adjacent to the belt. These are the most favoured locations. On rimmed cases, the head just in front of the rim is the diameter most often used.

All cases expand noticeably in these areas on first firing, whether with factory loads or handloads, so this technique cannot be used on this firing. That first firing will expand the case to match the dimensions of the chamber in which it has been fired and any further expansion on subsequent shots is a sure indication of very high chamber pressures.

Case head expansion after firing is the handloader’s key to acceptable pressures in his reloads. If the mike shows the cartridge case head has expanded by as much as .001” then that pressure is excessive for that shot in that gun. Some experts claim that even .0005” is too much, but by my rule of thumb this is the outside limit of permissable expansion. I always try to keep my working loads under .0001” expansion, and recommend this as a sensible limit for the average handloader. What it all boils down to is: if the mike shows measurable head expansion, then brass is beginning to flow because the pressure is too high. This is a sure indication that it is time to reduce the powder charge.

If, as we shoot a series of pressure loads, and check each increased powder charge with the mike, no pressure signs appear, the next heaviest charges are fired, and so on through the series. On a rare occasion, it may be that no sign of excessive pressure shows up even when you reach the listed maximum load. You may even be able to exceed the maximum charge weight recommendation in your manual with safety. But this only means that your particular rifle has a chamber dimensionally larger than standard, which makes it more tolerant of those maximum charges than the test gun used to compile the handbook data. Most loads are tested in a barrel with minimum dimensions which is attached to a universal receiver, but some ammomakers, like Norma for instance, take pressures using factory rifles.

This business of published velocity figures also needs some interpretation. Almost all rifles for standard centrefire big- game rifles are now furnished with 22-inch barrels, and rifles for the belted magnums are furnished with 24-inch barrels. But velocity figures published by the riflemakers are generally taken in 24-inch barrels if the cartridges are in the .270-.30-06 class and in 26-inch barrels if they are in the magnum class. One notable anomaly is the .30-30 Winchester as most of the arms for it are carbines and there will be a loss of at least 150fps in their stubby 20-inch barrels. This means, of course, that in the carbines it will
not be possible to duplicate the published velocities.

Reloading manuals list barrel lengths, but bulletmaking Hornady lists 6mm Remington data taken in a 22-inch barrel while their .243 data is taken in a 24-inch barrel. Every few weeks I get a letter from a reader complaining about how the velocity of his handload is not as high as what is listed in his manual. Alas, it not always possible to duplicate manual velocities, even when the same components are used. This is because of the variations we discussed previously, and too, his rifle may have a different barrel length and chamber dimensions. Factory ballistic tables should also be taken with a large grain of salt.

One ballistics lab experimented by shooting Remington factory ammo in a 6mm Remington rifle which had the barrel docked after every string. With the 100gn bullet, velocity was 3176 fps in the 26-inch length, 3084 fps in the 24-inch, 2997 fps in 22- inches, and 2955 fps in 20-inches. This translates into a loss per inch, not of the oft quoted 25 fps but more like to 45 fps!
Gun nuts love to argue about the performance of various cartridges and use as the basis for their arguments factory published data on muzzle velocity, retained velocity, energy, and bullet drop. This is about as futile as arguing with a little man who wasn’t there, because much data is based on figures for muzzle velocity obtained in a barrel length not furnished in factory rifles. And there’s the same difference with handloads using different bullets and different lots of powder.

All this is neither here nor there as far as the hunter who reloads is concerned. He should forget all about squeezing an extra 100 foot-seconds out of his handloads.It won’t make much difference to a deer whether the bullet that smacks into him has left the barrel at 3000 or at 3200. If it lands in a vital area, he’s a dead deer.

How much does an extra 100 fps gain you in flatness of trajectory? Not much! For example, take the Hornady 95gn SST driven at 3200fps and 3100fps with both loads zeroed at 200 metres. The difference in drop is only about 12mm, and the difference in energy delivered at 300 metres is barely 80 ft/lb.

Hot loads then, don’t flatten the trajectory enough to worry about but they do exact a penalty in shorter case and barrel life. Hardly a fair trade, wouldn’t you agree?

Comparing factory drop figures to your handload because they have the same velocity is a waste of time. I’ve found that they do not agree with bullet drop I get on the range. And when I check the velocity of factory ammo on a chronograph I find that in my rifle anyway, the delivered velocity does not always live up to advance notices. The only way to find out how effective your handload is and get valid figures is to chronograph it and then shoot it at various ranges.

A lot of rifle and bullet effectiveness lies in the head of the shooter. If he is a true believer then Old Betsy is going to reap death and destruction. A mate of mine uses a 7mm Rem. Mag. with the 150gn bullet on deer. Deadliest outfit he ever owned, he tells me. He swears by it and can’t see how I can shoot deer with a lousy .270 Winchester. I’d hate to disillusion him, but when he left his rifle with me for safe keeping while he went overseas, I snuck it out to the range and chronographed it. The muzzle velocity of the particular load he uses clocked just 2880fps. With a bullet of the same weight and somewhat superior ballistic coefficient in a Marlin XL 7 .270 Winchester with a 22-inch barrel I get over 50 fps more velocity than he does in his rifle.

He has read the figures, and he believes them. Because he believes them has unbounded faith in his rifle and reload. Because of this faith he shoots his rifle well, and because he shoots it well, it kills well. But if he ever found out that his pet load in his favourite rifle was giving him 220 fps less velocity than he thought he was getting, he would be devastated and his rifle would be certainly be ruined. So it’s going to remain my deep dark secret.

This article was first published in Sporting Shooter, December 2011


Read more at http://www.sportingshooter.com.au/news/ ... BvmRz9M.99

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PostPosted: Mon Dec 03, 2018 9:14 pm 
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Gbyleveldt wrote:
Eish Apie, ek verstaan nie jou antwoord nie. Heel moontlik onkunde...

Soos ek verstaan is nodespoed ‘n funksie van looplengte alleenlik? Jou manipuleer jou barreltime om op die nodespoed te kom deur middel van kruit lading, koeelgewig en dravlak van die koeel?

Help ‘n ou reg hier man asb.


Kom ons doen prentjies!

Hieronder my 6.5x55 met 23.75 duim loop met 139 Scenars en S365

Attachment:
QL 1.png


Barrel Time 1.295 - Node 1.2945 Spoed 2721fps

Dit is gekalibreer in my geweer.


Jy sal merk dat die verstekwaarde van S365 se BRF (.4400) redelik baie laer is as die gekalibreerde(.4599) lading

Ons kan dus aanneem dat die betrokke lot in my geweer heelwat vinniger brand as S365 se verstekwaarde.

Kom ons sê dat ek nou 'n stadiger lot S365 begin gebruik en die BRF werk uit op .4400.


Kyk wat gebeur die 2de table

Attachment:
QL2.png


Stadiger BRF beteken beter dopvul en vinniger nodespoed

Barrel time 1.295 - Node is 1.2945 Spoed 2737

Ek weet die verskille is akademies maar dis daar.

Dus hoe vinniger 'n betrokke bv S365 lot se brandtempo is hoe stadiger jou nodespoed(of dan trompspoed wat op 'n node is) en hoe stadiger die brandtempo hoe vinniger jou nodespoed(oftewel trompspoed wat op 'n node is) en hoe beter dopvul.


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PostPosted: Tue Dec 04, 2018 6:37 am 
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Dankie daarvoor Apie, ek sien nou presies wat jy bedoel en hoekom jy so se. Wat nie vir my sin maak nie, is hoe spoed (wat bereken word deur die periode - barrel time, gemeet oor ‘n afstand - barrel length) kan verander as albei barrel time en barrel length dieselfde bly nie? Dit is daai ene wat met my kop smokkel.

Ek dink daar is ‘n veranderlike wat ek mis; ek het ‘n fyn spesmaas dat die beskrywing “Barrel Time, 10% Pmax to Muzzle” die lydraad is. As jy kyk na die “chamber pressure” grafiek aan die linkerkant, begin die druk nie op nul teenoor barrel time wat op nul begin nie, maar teen 10% van die berekende druk, en ek verstaan dat daai berekende druk gebaseer word uit aanames wat QL maak; goed soos Weighing Factor, BRF, ens. Maar dis heeltemal te vroeg in die oggend vir my om oor sulke wrede somme te dink...


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PostPosted: Tue Dec 04, 2018 4:56 pm 
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Jy moet eindelik dink aan die versnelling van die koeel in die loop. Dit is hoekom jy met verskillende kruite verskillende snelhede kan kry met dieselfde barrel time.

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PostPosted: Wed Dec 05, 2018 10:15 am 
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Gbyleveldt wrote:
Dankie daarvoor Apie, ek sien nou presies wat jy bedoel en hoekom jy so se. Wat nie vir my sin maak nie, is hoe spoed (wat bereken word deur die periode - barrel time, gemeet oor ‘n afstand - barrel length) kan verander as albei barrel time en barrel length dieselfde bly nie? Dit is daai ene wat met my kop smokkel.

Ek dink daar is ‘n veranderlike wat ek mis; ek het ‘n fyn spesmaas dat die beskrywing “Barrel Time, 10% Pmax to Muzzle” die lydraad is. As jy kyk na die “chamber pressure” grafiek aan die linkerkant, begin die druk nie op nul teenoor barrel time wat op nul begin nie, maar teen 10% van die berekende druk, en ek verstaan dat daai berekende druk gebaseer word uit aanames wat QL maak; goed soos Weighing Factor, BRF, ens. Maar dis heeltemal te vroeg in die oggend vir my om oor sulke wrede somme te dink...


Goeie more Gbyleveld

Ek het hierdie al van te vore verduidelik en ek dink die voorbeeld van twee verskillende karre is dalk die mees geskikste in die geval. Kom ons vat n BMW M3 en n Audi RS4 van n paar jaar terug. Albei karre het 309kw gehad maar hulle torque syfers was verskillend sowel as hulle aandrywings stelsels. Alby het die 1km merk in presies dieselfde tydsduur gedoen maar hulle snelhede het verskil op die merk. Die BMW s'n was hoer as die Audi, maar die Audi se 0-100km syfer was weer op sy beurt vinniger. Laasgenoemde is eintlik irrelavant want dit dui net op die feit dat versnelling nie n liniere proses is nie, maar eerder gesien moet word as n unieke proses wat bestaan uit n klomp bydraende faktore. Nou as die skrywe lees wat Oom Driepoot geplaas het sal jy sien dat daar n magdom redes daarvoor is.

So dit kom neer dat al hierdie veranderlikes n rol speel om daai unieke trompsnelheid te kry wat vir daai spesifieke wapen en komponente van pas is. Nou moet jy ook verstaan dat n program soos QL nie huidiglik vir al die veranderlikes voorsiening kan maak nie, goed soos jou tipe primer, jump na die groewe, groewe se diameter, graveringsdruk van die koeel ens ens. So dit is die rede hoekom ek altyd aanbeveel om jou werklike node te soek om jou voorgestelde nodespoed om voorsiening te maak vir die spesifieke veranderlikes.

So om op te som, versnelling is uniek en nie n liniere of vaste proses nie en dit op sy beurt verklaar hoekom trompsnelheid verskil. So ja barreltime vir n spesifieke looplengte is n vaste waarde maar nie die trompsnelheid nie.

Cappie op jou vraag van dopuiteensetting meet by die basis. Oom Driepoot se skrywe spreek dit ook mooi aan. Dit is n tool vir ons as herlaaiers, maar in my ondervinding los dit baie keer n mens met meer vrae as antwoorde vir die eenvoudige rede dat n hele paar aspekte n invloed op daai waardes kan he. Dit was een van die hoof dinge wat PO Ackley destyds gebruik het om sy maksimum drukvlakke te bepaal en ons weet hoe ver uit hierdie metode uit was met drukaanwysings. Mates wat heel binne perke was volgens die standaard het baie keer in realiteit 80 000-90 000psi drukvlakke gelewer in druk toetslope.

Manne ek en Dale het n lekker gesprek gister gehad en om op te som kan ek julle die volgende se. Eerstens is dat QL sukkel met die 6.5 Creedmoor spesifiek. Drukvoorspelling korreleer nie met herlaaihandlydings of die realiteit op die staduim nie. In sekere gevalle word nodespoed ook geaffekteer daardeur. Ek weet nie of ons huidiglik met verstellings aan die WF genoegsaam vir hierdie sal kan kompenseer nie.

My voorstel sal wel die volgende wees. Moet nie gepubliseerde maksimum snelhede vir n komponent oorskrei nie. Indien jy QL op die default waarde gebruik beskou 51 000-52 000psi as jou absolute maksimum(onthou net hierdie is nie die werklike drukvlakke nie, maar wel wat ons met QL soos hy nou werk as ons maksimum gebruik). Indien jy n WF van 0.65 gebruik beskou 55 000-56 000psi as jou maksimum. Kyk na voorgestelde nodesnelhede met beide die WF en laai dan toets ladings wat alby daai noespoed voorspellings sal gee en skiet hulle. Sal julle asb ook so gaaf wees om julle ladings en die se gegewens vir my deur te stuur? Hoe meer informasie het hoe beter is die kans dat ons n werkbare oplossing kry met QL.

Groetnis
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PostPosted: Wed Dec 05, 2018 10:23 am 
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Hi Wouter.

Thank you for this explanation with respect to the node speed versus muzzle velocity.
I always better to explain this in simplistic terms.
It was a thoroughly enjoyable discussion I had with you yesterday and I am still working on the "modified" figures for the Creedmoor we discussed.
I will send them through to you as soon as I am confident with them.

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PostPosted: Wed Dec 05, 2018 10:27 am 
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Baie dankie vir die omvattende antwoord!

Hoe wil jy he moet ons ons ladings vir jou stuur? PM, of moet ons 'n draad begin daarvoor? Ek worry maar om sekere van hierdie goed publiek te maak, want ander manne kan die verkeerde gevolgtrekkings maak en pypbomme bou.

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PostPosted: Wed Dec 05, 2018 11:49 am 
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Gert

Julle kan my e-mail op wouter@palkor.co.za wat meskien die maklikste gaan wees. Ek is glad nie seker of n mens by n werkbare antwoord gaan uitkom nie en meskien gaan die enigste manier wees dat die vervaardigers van QL n hele nuwe algoritme gaan moet skryf vir die kaliber. Kom ons kyk maar.

Dale stuur maar wat jy het solank, meskien kom ons nog by dieselfde antwoorde uit.

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PostPosted: Wed Dec 05, 2018 1:19 pm 
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Dankie Wouter, ek het nou al twee Creedmoor's gekry wat op die node hardloop saam met QL. Node spoed is 2700 tot 2720.

Dan het ek ook nou al beleef wat julle beskryf hierbo waar die twee nie bymekaar uitkom nie, maar met verdere verfyning sonder QL skiet hulle mooi.

Wat almal maar net weer moet besef is dat QL net 'n hulpmiddel is om tot 'n spesifieke punt te kom in die herlaai proses en nie die alfa en omega nie(al dink sommiges so).


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PostPosted: Wed Dec 05, 2018 1:31 pm 
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Hallo Ruaan

Pesies! Dit bly net n tool en het maar sy uitdagings. n Bleddie handige een bygese. My drie Creedmoors tot nou toe was op die nommer in terme van nodespoed en barreltime voorspellings met die default waardes van QL. Verder practice ek maar wat ek preach deur altyd my nodeband te toets en ek wens meer QL gebruikers wil net hierdie eenvoudige maar tog so logiese raad volg. Dit sal soveel tyd en moeite spaar.

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Wout


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PostPosted: Wed Dec 05, 2018 1:47 pm 
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Dankie Wouter, ek vir jou 'n ou possie gestuur.


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PostPosted: Wed Dec 05, 2018 6:40 pm 
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Hierie hele creedmoor dong klink maar vir my na n gesukkel

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PostPosted: Wed Dec 05, 2018 6:50 pm 
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Capt. Oblivious wrote:
Hierie hele creedmoor dong klink maar vir my na n gesukkel


As ek geweet het wat ek nou weet toe ek die 6.5CM gekoop het ... het ek n Rem 700 SPS Varmint gekoop en dit n 6 SLR gemaak.

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PostPosted: Wed Dec 05, 2018 6:59 pm 
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Die een groep is geskiet met virgin brass en die ander groep met brass wat vir 2de keer geskiet word wat net geneck size is.

Kan dit so groot verskil maak in spoed?

Die klomp (12) skote reg onder was 41.9 en 42 in virgin brass so ek neem aan hulle spoed was Baie naby aan node. Het ook hulle met kneldemper geskiet om te sien of alles reg is.

Is ek reg as ek se ek Sal 41.7 moet skiet dat dit Baie naby aan node spoed gaan wees wat Dale gegee het van 2672.

Dankie vir die help en al die inligting het baie geleer uit die gespekke uit. [IMG]https://uploads.tapatalk-cdn.com/20181205/941eb60bbd053a8253f7f75cdfc69ed3.jpg[/IMG][IMG]https://uploads.tapatalk-cdn.com/20181205/1f6d131ea90e70a4840ce9b395947694.jpg[/IMG]

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PostPosted: Wed Dec 05, 2018 7:05 pm 
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Hiers van my CM se groepe


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PostPosted: Wed Dec 05, 2018 7:09 pm 
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^^^ Ek wil nie ‘n bok wees en die fout maak om voor jou verby te loop nie. Baie mooi geskiet!


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PostPosted: Wed Dec 05, 2018 7:15 pm 
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My Creed vandag op 200 geskiet. Het hom egter verkort na 20duim en koele is 123gr Scenar.


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PostPosted: Wed Dec 05, 2018 7:16 pm 
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19mm plakker.

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PostPosted: Wed Dec 05, 2018 8:21 pm 
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[quote="JJ777"]Die een groep is geskiet met virgin brass en die ander groep met brass wat vir 2de keer geskiet word wat net geneck size is.

Kan dit so groot verskil maak in spoed?

Die klomp (12) skote reg onder was 41.9 en 42 in virgin brass so ek neem aan hulle spoed was Baie naby aan node. Het ook hulle met kneldemper geskiet om te sien of alles reg is.

Is ek reg as ek se ek Sal 41.7 moet skiet dat dit Baie naby aan node spoed gaan wees wat Dale gegee het van 2672.

Dankie vir die help en al die inligting het baie geleer uit die gespekke uit. [

Jou 1ste foto, 42.1 en 42.4, my opinie, speel met seating depth sonder om lading te verander. Seat hulle .03 dieper en vlakker, ek kyk wat gebeur..


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PostPosted: Thu Dec 06, 2018 8:05 am 
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https://www.americanrifleman.org/Webcon ... edmoor.pdf

Gents
Please read this article carefully and take note that the original factory ammunition tested with 140 grain Hornady A Max bullets at 2820 fps where tested in a 28 inch barrel.

If we extrapolate this information to a 24 inch barrel with S365, it means that bullets in the 140 grain class should not exceed +- 2720 to 2730 fps from a 24 inch barrel.
At this speed the pressure is predicted to be +- 58500 to 59000 psi.

This also effectively means that to try and achieve 2800 fps from a 24 inch barrel your pressure would be at +- 64800 psi which exceeds SAAMI max and will shorten your case life and stretch your primer pockets, more so with the large rifle primer pockets.

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PostPosted: Thu Dec 06, 2018 8:42 am 
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Gbyleveldt wrote:
Dale,

As a matter of interest, this was my QL prediction for the 140gn Nosler CC's in a Howa 24" Bull Barrel. I'm not running S365 but IMR4350. I ended up settling for 41.8gn IMR4350 as that's the charge that showed the nicest groups and almost in the middle of a nice fat node. Speed ended up at 2717fps.

I'm curious as to your weighing factor of 0.6? Genuinely interested.


Hallo Gert

Nadat jy jou QL screenshot vir my gister ge-epos het het ek opgemerk jy gebruik n WF van 0.46 en nadat ek jou daaroor uitgevra het het jy genoem dit is die voorgestelde WF volgens Cassie Nienaber se formule wat deur Pierre van der Walt verwerk is vir die 6.5 Creedmoor.

Nou ter inligting vir die lede hier sal ek weer hierdeur gaan. Jy het genoem dat jou werklike nodespoed so 15ft/sek weg is van wat QL voorspel. Nou indien jy gehou het by die default WF waarde van 0.5 wat ons voorstel was jy presies op jou voorgestelde waarde wat bevestig wat ek se dat QL se nodespoed voorspelling reg is op die default waarde. Verder wys dit weereens dat verstellings aan jou WF wel n invloed op jou nodespoed voorspellings het.

Tweedens is druk weer ter sprake. Deur die WF te verlaag verhoog die voorgestelde spoed en verlaag die druk. Ek se weer dat mense moet baie mooi verstaan wat verstellings aan jou WF doen. WF is n efficiency glyskaal waar as jy hom ondertoe aanpas maak jy jou rondte meer efficient/effektief en omgekeerd vir as jy hom boontoe aanpas. Die verduideliking wat QL gee van meer en minder overbore is baie misleidend want hoe meer overbore jou rondte is is hy verseker nie meer efficient/effektief nie! So in jou geval Gert het jou drukvlakke af gekom op n lading wat al klaar baie naby aan die maksimum vir die kombinasie is. Ek moet bynoem dat jy wel Nosler se herlaai handlyding nageslaan het wat natuurlik altyd n baie goeie voorsorgmatreel is.

Ek hoop hierdie voorbeeld wys net weereens hoe gekompliseerd en potensieel gevaarlik dit is om enigsins aan jou WF te stel en wat se implikasies dit inhou. Eerstens peuter n mens met drukvlakke en al hoe n mens verstellings kan maak is om met die werklike drukvlakke te sit. Tweedens beinvloed dit n mens se nodespoed voorspellings wat weer op sy beurt die gebruik van QL en die nodeprogram as te ware oortollig maak, nie waar nie.

Gert het absoluut op goedertrou hier opgetree soos soveel ander mense ook en ek hoop hierdie voorbeeld kan n paar mense finaal tot insig laat kom.

Groetnis
Wouer


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PostPosted: Thu Dec 06, 2018 10:39 am 
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Baie dankie vir die terugvoer Wouter. Soos ek genoem het in my epos aan jou waardeer ek (en ek is seker baie ander manne) die informasie wat jy, Dale, oom Tripod, ens, bereid is om te deel op 'n publieke platform.

Soos baie manne met ervaring al gese het, moet nie net up QL se drukvlakke staat maak nie; dit is altyd 'n goeie idee om ander skrywes te raadpleeg as 'n 'sanity check'. Deur na die Nosler herlaai data te kyk vir my komponent keuse het ek gesien ek is naby aan maks (alhoewel nog binne perke) vir die spoed wat ek wou skiet.

Soos jy ook se, as jy nie elke veranderlike in QL reg verstaan nie dan kan jy hom maak om pypbomme te bou en jy sal nie eers dit besef nie. Ek was gelukkig; maar die volgende ou is dalk nie.

Weereens dankie vir almal se insette!!

Groete,

Gert


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