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Rifles, Reloading, Optics, Equipment
Reloading
Pressure signs on straight wall cases?
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<blockquote data-quote="bigedp51" data-source="post: 1371052" data-attributes="member: 28965"><p><span style="font-size: 12px"><strong>Below will not tell you chamber pressure, it will simply tell you the strength of the cases you are using. Example Lake City brass is harder than commercial brass with Lapua coming in second as far as hardness. "BUT" the flash hole web "thickness" adds radial strength to the base of the case making it stronger.</strong></span></p><p><span style="font-size: 12px"></span></p><p><span style="font-size: 12px"><strong><span style="font-size: 12px"><span style="color: #0000b3"><strong>Simple Trick for Monitoring Pressure of Your Rifle Reloads</strong></span></span></strong></span></p><p><span style="font-size: 12px"><strong><span style="font-size: 12px"><span style="color: #0000b3"><strong><a href="http://www.hodgdonreloading.com/reloading-education/tips-and-tricks/simple-trick-monitoring-pressure-your-rifle-reloads" target="_blank">http://www.hodgdonreloading.com/reloading-education/tips-and-tricks/simple-trick-monitoring-pressure-your-rifle-reloads</a></strong></span></span></strong></span></p><p><span style="font-size: 12px"></span></p><p><span style="font-size: 12px"><strong><span style="color: #0000b3">"One of the first rules of handloading is to always follow the approved reload data. The cautious reloader gradually works up to approved maximum loads to ensure his particular gun does not show pressure signs. Generally this is visual observation of the fired shell case head and primer. There is another slick way to check for pressure signs if you are interested.</span></strong></span></p><p> <span style="font-size: 12px"></span></p><p><span style="font-size: 12px"><strong><span style="color: #0000b3">Using a blade micrometer that measures in ten thousandths (.0001"), new, unfired cases can be gauged before and after firing to determine reasonably accurate maximum loads. Micrometers measuring in thousandths (.001") are insufficiently accurate to perform these measurements, and should not be used. Previously fired cases cannot be used accurately due to various levels of brass hardening. Measurement is taken just ahead of the extractor groove on the case head and must be taken at the same place on the case before and after firing. By placing a small mark on the case head – entering the cartridge in the chamber with mark at 12 o'clock – a consistently accurate measurement can be taken with each firing. </span></strong></span></p><p> <span style="font-size: 12px"></span></p><p><span style="font-size: 12px"><strong><span style="color: #0000b3">Lower pressure rounds, like the .30-30 Winchester, usually yield maximum pressures at .0003"-.0004" expansion. Modern cartridges, like the .223 Remington, will show maximum pressure at .0004"-.0005", while .308 Winchester, .270 Winchester, etc., typically yield .0005"-.0006" expansion at max pressure. Magnums, like the .300 Winchester Magnum, show maximums at .0006"-.0007" expansion, and should be measured on the belt. </span></strong></span></p><p> <span style="font-size: 12px"></span></p><p><span style="font-size: 12px"><strong><span style="color: #0000b3">In conjunction with these measurements, case head signs of pressure should be monitored as well. These signs include very flat primers, slightly cratered primers, ejector marks on the case head, and stiff extraction. All these case head signs indicate high pressure, and loads should be reduced until these signs disappear.</span></strong></span></p><p> <span style="font-size: 12px"></span></p><p><span style="font-size: 12px"><strong><span style="color: #0000b3">As always, start with the beginning load listed, and cautiously work up to the maximum shown for that set of components, using the methods listed herein."</span></strong></span></p><p><span style="font-size: 12px"></span></p><p><span style="font-size: 12px"><strong><span style="font-size: 12px"><strong>Example below and why Federal brass has over sized primer pockets sooner than cases with thicker flash hole webs. So again measuring base expansion doesn't tell actual chamber pressure, but it does tell you when you are pushing that brand of brass to hard or beyond its elastic limits.</strong></span></strong></span></p><p><span style="font-size: 12px"></span></p><p><span style="font-size: 12px"><strong><span style="font-size: 12px"><strong><img src="https://i.imgur.com/cYeTsDp.jpg" alt="" class="fr-fic fr-dii fr-draggable " style="" /></strong></span></strong></span></p><p><span style="font-size: 12px"></span></p></blockquote><p></p>
[QUOTE="bigedp51, post: 1371052, member: 28965"] [SIZE=3][B]Below will not tell you chamber pressure, it will simply tell you the strength of the cases you are using. Example Lake City brass is harder than commercial brass with Lapua coming in second as far as hardness. "BUT" the flash hole web "thickness" adds radial strength to the base of the case making it stronger.[/B] [B][SIZE=3][COLOR=#0000b3][B]Simple Trick for Monitoring Pressure of Your Rifle Reloads[/B][/COLOR][/SIZE][/B] [B][SIZE=3][COLOR=#0000b3][B][URL]http://www.hodgdonreloading.com/reloading-education/tips-and-tricks/simple-trick-monitoring-pressure-your-rifle-reloads[/URL][/B][/COLOR][/SIZE][/B] [B][/B] [B][COLOR=#0000b3]"One of the first rules of handloading is to always follow the approved reload data. The cautious reloader gradually works up to approved maximum loads to ensure his particular gun does not show pressure signs. Generally this is visual observation of the fired shell case head and primer. There is another slick way to check for pressure signs if you are interested.[/COLOR][/B] [B][COLOR=#0000b3] [/COLOR][/B] [B][COLOR=#0000b3]Using a blade micrometer that measures in ten thousandths (.0001"), new, unfired cases can be gauged before and after firing to determine reasonably accurate maximum loads. Micrometers measuring in thousandths (.001") are insufficiently accurate to perform these measurements, and should not be used. Previously fired cases cannot be used accurately due to various levels of brass hardening. Measurement is taken just ahead of the extractor groove on the case head and must be taken at the same place on the case before and after firing. By placing a small mark on the case head – entering the cartridge in the chamber with mark at 12 o’clock – a consistently accurate measurement can be taken with each firing. [/COLOR][/B] [B][COLOR=#0000b3] [/COLOR][/B] [B][COLOR=#0000b3]Lower pressure rounds, like the .30-30 Winchester, usually yield maximum pressures at .0003"-.0004" expansion. Modern cartridges, like the .223 Remington, will show maximum pressure at .0004"-.0005", while .308 Winchester, .270 Winchester, etc., typically yield .0005"-.0006" expansion at max pressure. Magnums, like the .300 Winchester Magnum, show maximums at .0006”-.0007” expansion, and should be measured on the belt. [/COLOR][/B] [B][COLOR=#0000b3] [/COLOR][/B] [B][COLOR=#0000b3]In conjunction with these measurements, case head signs of pressure should be monitored as well. These signs include very flat primers, slightly cratered primers, ejector marks on the case head, and stiff extraction. All these case head signs indicate high pressure, and loads should be reduced until these signs disappear.[/COLOR][/B] [B][COLOR=#0000b3] [/COLOR][/B] [B][COLOR=#0000b3]As always, start with the beginning load listed, and cautiously work up to the maximum shown for that set of components, using the methods listed herein."[/COLOR][/B] [B][/B] [B][SIZE=3][B]Example below and why Federal brass has over sized primer pockets sooner than cases with thicker flash hole webs. So again measuring base expansion doesn't tell actual chamber pressure, but it does tell you when you are pushing that brand of brass to hard or beyond its elastic limits.[/B][/SIZE][/B] [B][SIZE=3][/SIZE][/B] [B][SIZE=3][B][IMG]https://i.imgur.com/cYeTsDp.jpg[/IMG][/B][/SIZE][/B] [B][/B][/SIZE] [/QUOTE]
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Pressure signs on straight wall cases?
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