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Rifles, Reloading, Optics, Equipment
Reloading
Would this be fair to say?
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<blockquote data-quote="Mr. Magoo" data-source="post: 2778353" data-attributes="member: 124360"><p>Are your first and last sentences directed at me? I don't believe jam is king.</p><p></p><p>There's WAY more to it than that, as I tried (apparently unsusccsessfully) to illustrate earlier. Seating depth not only changes the presure curve because of how soon after ignition pressure from bullet engraving starts, but also effective starting combustion chamber volume. Immediately after ignition you get not just one pressure spike, but several.</p><p></p><p>Bullet shape (and leade angle) also affects this time/pressure curve, as a tangent ogive eases into the riflings slightly less abruptly than secant, slightly muting the peak off the spike.</p><p></p><p>If one were to look at the map of the pressure curve, you would see the pressure spikes from the very first flicker of flame from the primer, the ignition of the first powder, the easing of pressure for a tiny microsecond after bullet movement before rifling engagement, another spike at bullet's first contact with rifling, a very slight plateu of pressure when the brass expands in the middle, then the big hit of pressure when a majority of the brass expansion is stopped by the chamber wall and full engraving starts. Exceeding the plastic limit of the brass (vs not) will also change the curve.</p><p></p><p> The rest of the pressure curve from there on is dedermined by the powder, bullet, and barrel correlation, burn rate and barrel temperature. I could go on and on about this and left out alot but am trying to simplify it for brevity.</p><p></p><p>My thoughts about manipulating this curve and its peaks/ valleys in a way that produces accuracy have been put to the test, and it has worked for me.</p><p></p><p>Seating depth is just one of the key ways to manipulate this curve via volume and pressure peak timing changes.</p><p></p><p>Change one aspect, and you change them all.</p><p></p><p>This really hasnt even begun to talk about bullet to bore entry relationships with regards to the different shapes /hardness of bullets. Or how pressure, and what it does to the brass, and the brass-to bullet relationship during entry into the riflings. Another day.</p><p></p><p>Edit: I do think you're onto something starting seating depth changes first. Might try it.</p></blockquote><p></p>
[QUOTE="Mr. Magoo, post: 2778353, member: 124360"] Are your first and last sentences directed at me? I don't believe jam is king. There's WAY more to it than that, as I tried (apparently unsusccsessfully) to illustrate earlier. Seating depth not only changes the presure curve because of how soon after ignition pressure from bullet engraving starts, but also effective starting combustion chamber volume. Immediately after ignition you get not just one pressure spike, but several. Bullet shape (and leade angle) also affects this time/pressure curve, as a tangent ogive eases into the riflings slightly less abruptly than secant, slightly muting the peak off the spike. If one were to look at the map of the pressure curve, you would see the pressure spikes from the very first flicker of flame from the primer, the ignition of the first powder, the easing of pressure for a tiny microsecond after bullet movement before rifling engagement, another spike at bullet's first contact with rifling, a very slight plateu of pressure when the brass expands in the middle, then the big hit of pressure when a majority of the brass expansion is stopped by the chamber wall and full engraving starts. Exceeding the plastic limit of the brass (vs not) will also change the curve. The rest of the pressure curve from there on is dedermined by the powder, bullet, and barrel correlation, burn rate and barrel temperature. I could go on and on about this and left out alot but am trying to simplify it for brevity. My thoughts about manipulating this curve and its peaks/ valleys in a way that produces accuracy have been put to the test, and it has worked for me. Seating depth is just one of the key ways to manipulate this curve via volume and pressure peak timing changes. Change one aspect, and you change them all. This really hasnt even begun to talk about bullet to bore entry relationships with regards to the different shapes /hardness of bullets. Or how pressure, and what it does to the brass, and the brass-to bullet relationship during entry into the riflings. Another day. Edit: I do think you're onto something starting seating depth changes first. Might try it. [/QUOTE]
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Reloading
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