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Rifles, Reloading, Optics, Equipment
Rifles, Bullets, Barrels & Ballistics
Super Fast Twist Barrels for Hammer Bullets
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<blockquote data-quote="tacomHQ" data-source="post: 2886439" data-attributes="member: 67159"><p>Let's see if we got this right... please chime in. Going from 12-8 (which we have operating). Just using simple linear values. </p><p></p><p>Using a .338cal for base line- an 8T and a 12T- a .75inch bullet contact area:</p><p>In this example the bullet will engrave by +.0105 as compared to the land width.</p><p>It will gain (+/-).0025" of width per 1" of gain over its 12inches. </p><p>If I extend that to 24inches it would be (+/-) .00125" of width per 1" of gain over the 24"</p><p>If I turn this into percentages a change of +/-17% occurs. Can that potentially translate into 17% less initial pressure? If a longer lead reduces pressure less initial twist should reduce pressure.</p><p>Anecdotal (new term I have heard describing our results) wise- our back to back comparisons have yielded more velocity on less powder- Anecdotal only and 3rd party. </p><p>A few years back at K2M John B (don't want to mis-spell a last name) a guy known for a carriage mounted 50cal- took third without a spotter. He was shooting a lighter bullet at a higher velocity than other competitors - a true outlier- with a slower twist rate comparatively speaking. Speed was used to stabilize his bullet as the bullet he was using required a book 9T (though actually 7.5T was required)- his velocity allowed him to shoot a 13T. </p><p>[ATTACH=full]487641[/ATTACH]</p></blockquote><p></p>
[QUOTE="tacomHQ, post: 2886439, member: 67159"] Let's see if we got this right... please chime in. Going from 12-8 (which we have operating). Just using simple linear values. Using a .338cal for base line- an 8T and a 12T- a .75inch bullet contact area: In this example the bullet will engrave by +.0105 as compared to the land width. It will gain (+/-).0025" of width per 1" of gain over its 12inches. If I extend that to 24inches it would be (+/-) .00125" of width per 1" of gain over the 24" If I turn this into percentages a change of +/-17% occurs. Can that potentially translate into 17% less initial pressure? If a longer lead reduces pressure less initial twist should reduce pressure. Anecdotal (new term I have heard describing our results) wise- our back to back comparisons have yielded more velocity on less powder- Anecdotal only and 3rd party. A few years back at K2M John B (don't want to mis-spell a last name) a guy known for a carriage mounted 50cal- took third without a spotter. He was shooting a lighter bullet at a higher velocity than other competitors - a true outlier- with a slower twist rate comparatively speaking. Speed was used to stabilize his bullet as the bullet he was using required a book 9T (though actually 7.5T was required)- his velocity allowed him to shoot a 13T. [ATTACH type="full"]487641[/ATTACH] [/QUOTE]
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Rifles, Reloading, Optics, Equipment
Rifles, Bullets, Barrels & Ballistics
Super Fast Twist Barrels for Hammer Bullets
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