Author Topic: Spin Rate  (Read 1864 times)

mobilehomer

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Spin Rate
« on: March 08, 2016, 04:37:43 PM »
I have often wondered just how much effect spin rate has on the accuracy of a given projectile. This is a product of twist and speed. Could this be part of why some pellets shoot better in one gun or the other? I know it has a great deal to do with stability in flight. Just wondering...


Maximus Hunter
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oldpro

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Re: Spin Rate
« Reply #1 on: March 08, 2016, 05:01:57 PM »
 thats a great question and to expand on it can you Over spin a projectile? I know you can under spin them.
  • Mount Shasta Ca.

mobilehomer

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Re: Spin Rate
« Reply #2 on: March 08, 2016, 07:18:26 PM »
Oldpro, I know this about PB, but back in the late seventies or early eighties, one of the bullet makers came out with a great light weight .223 projectile. One guy loaded and tested in his super accurate bolt rifle. It wouldn't even print on the paper. He shot the ground about 20 yards in front of the bench and NO hit!! The bullet was so frangible that the speed caused so much spin that the bullet vaporized!! Not likely with a pellet, but yes, you can overspin.
Maximus Hunter
4-16X56 UTG
2400KT
Bushnell 3-12X40 AR 223
Trail NP2 .22
UTG 10X50

rsterne

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Re: Spin Rate
« Reply #3 on: March 08, 2016, 07:37:38 PM »
If you spin a pellet or bullet too fast, it can develop Dynamic Instability.... This causes the projectile to spiral or corkscrew.... not uncommon with pellets driven too fast once they get downrange.... They lose forward speed faster than they lose RPM, and become Dynamically Unstable and corkscrew.... In theory, a slower twist rate should cure it.... not the easiest thing to change.... so most guys just shoot them slower if they notice a spiral.... The nose of the pellet is actually doing this about it's own axis....



It is following the path of the end of the blue rod....  :o

Bob
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