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Gain additional velocity by shooting prone ...
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<blockquote data-quote="GeorgeS" data-source="post: 1522548" data-attributes="member: 107925"><p>There is rifle movement before the bullet leaves the muzzle; there are ample high-speed videos that establish that. Bullet transit time down the barrel is about a millisecond long - plenty of time for the rifle to move backwards a tad. In a 1911, for example, the slide is moving back before the bullet is out of the barrel. A rifle barrel is also flexing before bullet departure. </p><p></p><p>A muzzle brake can't affect the velocity of the bullet, because - unless the bullet is really loose in the barrel, and there's abundant blowby of gas - its effect is only on the gas exiting following bullet departure. </p><p></p><p>A muzzle blast effect that changes muzzle velocity as measured downrange a bit could be a result of muzzle blast affecting the alignment of the bullet with the axis of travel, effectively changing the drag component on the bullet. The bullet's center of pressure and center of mass are not coincident, so there's a rotating moment around the center of mass that would be applied to the bullet by a ground-reflected sideways force. Unlike the case with a chronograph a few meters from the muzzle, however, I doubt it would show on a magnetospeed, because it measures speed before the drag could significantly affect velocity. </p><p></p><p>A blast shield would most likely only affect the initial chronograph trigger caused by muzzle blast gases moving ahead of the bullet; the effect should be to show a lower velocity when a blast shield is absent, because the bullet would trigger the second chronograph sensor longer after the first sensor responded to the gas. That would depend on the sensitivity of the sensors to unburned powder, etc.</p><p></p><p>An empirical test would be good, however, since in theory, theory and practice are the same - but in practice, theory and practice are often very different . . .</p></blockquote><p></p>
[QUOTE="GeorgeS, post: 1522548, member: 107925"] There is rifle movement before the bullet leaves the muzzle; there are ample high-speed videos that establish that. Bullet transit time down the barrel is about a millisecond long - plenty of time for the rifle to move backwards a tad. In a 1911, for example, the slide is moving back before the bullet is out of the barrel. A rifle barrel is also flexing before bullet departure. A muzzle brake can't affect the velocity of the bullet, because - unless the bullet is really loose in the barrel, and there's abundant blowby of gas - its effect is only on the gas exiting following bullet departure. A muzzle blast effect that changes muzzle velocity as measured downrange a bit could be a result of muzzle blast affecting the alignment of the bullet with the axis of travel, effectively changing the drag component on the bullet. The bullet's center of pressure and center of mass are not coincident, so there's a rotating moment around the center of mass that would be applied to the bullet by a ground-reflected sideways force. Unlike the case with a chronograph a few meters from the muzzle, however, I doubt it would show on a magnetospeed, because it measures speed before the drag could significantly affect velocity. A blast shield would most likely only affect the initial chronograph trigger caused by muzzle blast gases moving ahead of the bullet; the effect should be to show a lower velocity when a blast shield is absent, because the bullet would trigger the second chronograph sensor longer after the first sensor responded to the gas. That would depend on the sensitivity of the sensors to unburned powder, etc. An empirical test would be good, however, since in theory, theory and practice are the same - but in practice, theory and practice are often very different . . . [/QUOTE]
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