The reason for ridges on a pellet skirt.

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   I hadn't read your last post before I wrote mine. Yep spot on, a side wind will cause an elevation change, how much I have no idea.

I would have guessed ridges on a pellet would make the effect more pronounced, as that is why golf balls are dimpled and not smooth ??

I have wondered why some pellets have ridges, but since most of the good ones don't seem to I haven't bothered trying to find out.

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xyon Members Profile Send Private Message Find Members Posts Add to Buddy List Senior Member Joined: 20 Dec 2016 Location: Canterbury Status: Offline Posts: 133	Post Options Post Reply Quote xyon Report Post Thanks(0) Quote Reply Topic: The reason for ridges on a pellet skirt. Posted: 18 May 2017 at 3:59pm
	I hadn't read your last post before I wrote mine. Yep spot on, a side wind will cause an elevation change, how much I have no idea. I would have guessed ridges on a pellet would make the effect more pronounced, as that is why golf balls are dimpled and not smooth ?? I have wondered why some pellets have ridges, but since most of the good ones don't seem to I haven't bothered trying to find out.
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Pauly5 Members Profile Send Private Message Find Members Posts Add to Buddy List Senior Member Joined: 10 Mar 2013 Location: Titahi Bay Status: Offline Posts: 1174	Post Options Post Reply Quote Pauly5 Report Post Thanks(0) Quote Reply Posted: 18 May 2017 at 12:22pm
	If I understand you right, there will be no effect unless there is a wind acting from the side. So really no impact until there is wind.

xyon Members Profile Send Private Message Find Members Posts Add to Buddy List Senior Member Joined: 20 Dec 2016 Location: Canterbury Status: Offline Posts: 133	Post Options Post Reply Quote xyon Report Post Thanks(0) Quote Reply Posted: 18 May 2017 at 12:08pm
	I'm pretty sure this statement is wrong. "In brief this means that the spinning of the pellet as it travels produces a low pressure area to the side of the pellet into which it is sucked. That gives a pellet deviation to the side of the direct line from muzzle to target. Left to a clockwise rotating pellet. " There is no difference between the left or right side (or top and bottom for that matter) when the pellet is rotating. The magnus effect will change the flight path when the axis of rotation not in the same direction as the air flow over the projectile (eg a crosswind). See http://en.wikipedia.org/wiki/External_ballistics#Magnus_effect
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Pauly5 Members Profile Send Private Message Find Members Posts Add to Buddy List Senior Member Joined: 10 Mar 2013 Location: Titahi Bay Status: Offline Posts: 1174	Post Options Post Reply Quote Pauly5 Report Post Thanks(0) Quote Reply Posted: 16 May 2017 at 7:43pm
	I did. Very interesting. So a pellet would either go up or down if there is a side wind. It would need a vertical wind to move sideways. Have I got that right? So in theory in a certain side wind, your pellet may not drop as much as you would expect. As nova said probably nothing noticeable but all the same interesting.

pete Members Profile Send Private Message Find Members Posts Add to Buddy List Member Joined: 13 Sep 2015 Location: Christchurch Status: Offline Posts: 14	Post Options Post Reply Quote pete Report Post Thanks(0) Quote Reply Posted: 16 May 2017 at 7:30pm
	yer need to google "flettener rotor" Mr Flettener built a ship that used the magnus effect to power it.. .
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nunga Members Profile Send Private Message Find Members Posts Visit Members Homepage Add to Buddy List Forum Moderator Joined: 08 Mar 2013 Location: Pukekohe Status: Offline Posts: 824	Post Options Post Reply Quote nunga Report Post Thanks(0) Quote Reply Posted: 16 May 2017 at 12:14pm
	Paul is right about the cricket ball, thats why they shine only one side of the seam to get the ball to swing through the air when bowling. the seam of the cricket ball normally stays straight up and down when bowling
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Novagun Members Profile Send Private Message Find Members Posts Add to Buddy List Groupie Joined: 13 Dec 2016 Location: Wellington Status: Offline Posts: 62	Post Options Post Reply Quote Novagun Report Post Thanks(0) Quote Reply Posted: 16 May 2017 at 10:07am
	Yes but it also has seams which must shift air around its surface. And tennis balls, they both get lobed with spin.

Pauly5 Members Profile Send Private Message Find Members Posts Add to Buddy List Senior Member Joined: 10 Mar 2013 Location: Titahi Bay Status: Offline Posts: 1174	Post Options Post Reply Quote Pauly5 Report Post Thanks(0) Quote Reply Posted: 16 May 2017 at 8:00am
	But what if you're OCD? Is that one hole group exactly where you aimed? I would say the cricket ball moves because of drag on one side and shiny the other.

Novagun Members Profile Send Private Message Find Members Posts Add to Buddy List Groupie Joined: 13 Dec 2016 Location: Wellington Status: Offline Posts: 62	Post Options Post Reply Quote Novagun Report Post Thanks(0) Quote Reply Posted: 15 May 2017 at 9:15pm
	How far off does it move the pellet. Who knows, who cares but it is definitely there. If you put the pellet in the pigeons head that is good. In my case all my five shot one hole groups are just as good.

Novagun Members Profile Send Private Message Find Members Posts Add to Buddy List Groupie Joined: 13 Dec 2016 Location: Wellington Status: Offline Posts: 62	Post Options Post Reply Quote Novagun Report Post Thanks(0) Quote Reply Posted: 15 May 2017 at 9:10pm
	I don't think calibre matters nor does velocity at least at small speeds. The magnus effect is used markedly on cricket balls, golf balls, basket balls which are all slow moving. With rifle bullets I think high power overcomes many occurences because bullets go really fast.