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Post by magnumwheelman on Jul 29, 2022 22:23:08 GMT -5
My retired tool and die. buddy wants me to work up a load for a 6.5 rifle he built long ago… he is thinking I should check it for accuracy at 300 yards
Just guessing, that the purpose of a gain twist barrel, that the chamber pressure is lower at firing, and the bullet picks up rotational speed further down the barrel, maybe handy on old military rifle actions??? As that’s what this rifle was built on
Faster or slower powders better / more accurate???
Any help???
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Post by potatojudge on Jul 29, 2022 22:26:16 GMT -5
I don't think there's anything wrong with gain twist, but standard barrels are setting world records currently so that tells you something.
I think some barrels are fast, others slow, and most of us don't have pressure testing equipment.
So aside from speculation, I'd just work up a load like normal with the popular powders for that round (or what you have on hand).
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Post by magnumwheelman on Jul 29, 2022 22:27:05 GMT -5
Thanks…I think a lot of the Newton rifles were gain twist??? Maybe it was just a 60’s expiriment
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aciera
.375 Atomic
Posts: 2,128
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Post by aciera on Jul 30, 2022 8:36:54 GMT -5
My retired tool and die. buddy wants me to work up a load for a 6.5 rifle he built long ago… he is thinking I should check it for accuracy at 300 yards Just guessing, that the purpose of a gain twist barrel, that the chamber pressure is lower at firing, and the bullet picks up rotational speed further down the barrel, maybe handy on old military rifle actions??? As that’s what this rifle was built on Faster or slower powders better / more accurate??? Any help??? Pressure is HIGHER at firing. Less twist means less pressure built. That’s the way paradox rifles work. Bullet was smaller than bore and pressure was down by the time it hit the rifling. Many views on gain twist. |
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Post by zeus on Jul 31, 2022 0:24:27 GMT -5
I run gain twist on some of the king range rifles. No complaints. Not sure if it’s an advantage to me though.
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jwp475
.375 Atomic
Posts: 1,084
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Post by jwp475 on Jul 31, 2022 5:23:19 GMT -5
Twist has no appreciable effect on pressure. Once the bullet is engraved the amount of rotation isn't a factor
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jwp475
.375 Atomic
Posts: 1,084
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Post by jwp475 on Jul 31, 2022 5:59:38 GMT -5
Rock Creek barrels have a slight gain twist.
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Post by zeus on Jul 31, 2022 17:14:00 GMT -5
My retired tool and die. buddy wants me to work up a load for a 6.5 rifle he built long ago… he is thinking I should check it for accuracy at 300 yards Just guessing, that the purpose of a gain twist barrel, that the chamber pressure is lower at firing, and the bullet picks up rotational speed further down the barrel, maybe handy on old military rifle actions??? As that’s what this rifle was built on Faster or slower powders better / more accurate??? Any help??? Pressure is HIGHER at firing. Less twist means less pressure built. That’s the way paradox rifles work. Bullet was smaller than bore and pressure was down by the time it hit the rifling. Many views on gain twist. Gain twist is less at start speeding up to the end. So a 9.5-9 twist for instance. The rotation is faster at the end than the beginning. |
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Post by magnumwheelman on Jul 31, 2022 17:37:58 GMT -5
That was my I understanding
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aciera
.375 Atomic
Posts: 2,128
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Post by aciera on Jul 31, 2022 17:48:55 GMT -5
Yup exactly
But I’m not a word smith.
Reduce pressure
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