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Rifles, Reloading, Optics, Equipment
Reloading
Acceptable Powder Charge variance
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<blockquote data-quote="Pdvdh" data-source="post: 1312582" data-attributes="member: 4191"><p>Thought about this some more. The barrel length on the majority of ARs in use in the country are undoubtedly the M4 Carbines. Those ARs have 16" long barrels, and the gas port which drives the bolt and bolt carrier back is located closer to the chamber on the 16" long carbine model barrels than on 18", 20", or longer barreled models. </p><p></p><p>I don't know if the bolt begins moving before the bullets leave the muzzle on ARs or not. But the pressure on the 16" carbine gas actions hits the gas port <u>earlier</u> during bullet flight down the bore than on the ARs with mid-length or rifle-length gas tubes/ports. So the port location and port diameter on the 16" M4 carbine ARs, like mine, may be the culprit. If the pressure is more variable due to the carbine length gas port before the bullet leaves the muzzle, or if the bolt begins to move before the bullet clears the muzzle - either one or both combined could adversely affect ES/SD.</p><p></p><p>Perhaps that's why it's not too difficult to find a number of AR 15 owner's experiencing higher ES/SD. Most of them are shooting M4 Carbines with 16" carbine length gas tubes/ports. This is my running suspicion and theory for the time being. I presume you have a rifle length gas tube and port on your 24" barreled AR?</p></blockquote><p></p>
[QUOTE="Pdvdh, post: 1312582, member: 4191"] Thought about this some more. The barrel length on the majority of ARs in use in the country are undoubtedly the M4 Carbines. Those ARs have 16" long barrels, and the gas port which drives the bolt and bolt carrier back is located closer to the chamber on the 16" long carbine model barrels than on 18", 20", or longer barreled models. I don't know if the bolt begins moving before the bullets leave the muzzle on ARs or not. But the pressure on the 16" carbine gas actions hits the gas port [U]earlier[/U] during bullet flight down the bore than on the ARs with mid-length or rifle-length gas tubes/ports. So the port location and port diameter on the 16" M4 carbine ARs, like mine, may be the culprit. If the pressure is more variable due to the carbine length gas port before the bullet leaves the muzzle, or if the bolt begins to move before the bullet clears the muzzle - either one or both combined could adversely affect ES/SD. Perhaps that's why it's not too difficult to find a number of AR 15 owner's experiencing higher ES/SD. Most of them are shooting M4 Carbines with 16" carbine length gas tubes/ports. This is my running suspicion and theory for the time being. I presume you have a rifle length gas tube and port on your 24" barreled AR? [/QUOTE]
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Rifles, Reloading, Optics, Equipment
Reloading
Acceptable Powder Charge variance
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