Pellet flight video .. sharing what I see now.

[Yrrah]

All shot at 71 yards with BSA John Bowkett Hornet .22 cal PCP. (Not the pumpkin).

Left click each video address to open and then you might have to wait a while for them to load and begin or left click the bottom left corner once or twice to get it started. (Edit) If the picture hesitates be patient and it should continue.

Two groups of 3 shots each at 71 yards with JSB Exact 18.1 and 15.9 gr pellets.

There was quite a light (edit) left to right wind.

http://smg.photobucket.com/albums/v392/ ... ated51.mp4

Which is worst: damage to pellet skirts or damage to pellet heads? Guess and then watch the videos.

Skirts filed thus:



Then shot at 71 yards. Watch the flight pattern: Now a right to left wind.

http://smg.photobucket.com/albums/v392/ ... ttestA.mp4

Heads filed thus:



Then shot at 71 yards. Same right ot left wind.

http://smg.photobucket.com/albums/v392/ ... dated1.mp4

Are all pointed pellets inaccurate beyond 25 yards? Guess and then view the video:
3 JSB .22 Stratons and then 2 Gamo Master Points. They weigh the same and both are pointed : Same wind.

http://smg.photobucket.com/albums/v392/ ... Videos.mp4

Watch it again ... You may get an inkling as to what causes some of those "fliers". Who is rushing out to buy Gamos

Let me know if you enjoyed these and I may be encouraged to show more as time rolls by.

Like this: A 0.25 cal Predator Polymag drilling a pumpkin: Wait for all the bits to descend out of the sky.

http://smg.photobucket.com/albums/v392/ ... MG0906.mp4

I am learning how to do all this so I hope it all opens for you to read and to view.

Kind regards, Yrrah.

[JD]

Nice videos Harry and nice shooting.

Have to say I was surprised, I thought the tail damage would have more of an effect on the grouping with those filed JSB's but the tail damaged still grouped quite well. Do you think the difference might have more to do with the mass of the lead removed on the head vs tail and the effect that has on balance? ie. Filing lead off the head of the pellet causes more issues with pellet balance around the rotating axis causing it to corkscrew?

You seem to have the camera work sorted out now and getting some god vids .

FWIW I have shot Gamo Pro Magnums (domed) with similar results. Not surprising when you have a close (well not even that close) look at them. They look like garbage in the tin and shoot like garbage. Compared besides a JSB the difference is night and day. The best thing for gamo pellets is to melt them down into fishing sinker, because as pellets they are a waste of lead that could have been put to a better use.

It's about time I really stretched the legs on the S400 and see how it can shoot at distance. Might be time to purchase a decent rear bag.

Thanks,

JD

[Yrrah]

Nice videos Harry and nice shooting.

Have to say I was surprised, I thought the tail damage would have more of an effect on the grouping with those filed JSB's but the tail damaged still grouped quite well. Do you think the difference might have more to do with the mass of the lead removed on the head vs tail and the effect that has on balance? ie. Filing lead off the head of the pellet causes more issues with pellet balance around the rotating axis causing it to corkscrew?

You seem to have the camera work sorted out now and getting some god vids .

FWIW I have shot Gamo Pro Magnums (domed) with similar results. Not surprising when you have a close (well not even that close) look at them. They look like garbage in the tin and shoot like garbage. Compared besides a JSB the difference is night and day. The best thing for gamo pellets is to melt them down into fishing sinker, because as pellets they are a waste of lead that could have been put to a better use.

It's about time I really stretched the legs on the S400 and see how it can shoot at distance. Might be time to purchase a decent rear bag.

Thanks,

JD

Yes I think the move of the C of G a little rearwards is part of the problem. Then the imbalance of the head sets it up for precession and the oncoming airstream then forces it into the spiral. In the case of skirt damage only, the weight is shifted further forward and the drag on the lightened rear end is apparently enough to keep the pellet dynamically stable. Looking closely it seems one did lose it a tad towards the end of its flight. There was a reasonable wind out there too. ... The fact that I indexed the damage into the chamber allowed for quite good groups to result regardless of the severe damage. ...

Wait 'til you see the comparison of flight between .20 cal JSBs and the old Sheridan Bantams ......... shot from a Sheridan ..... ... Best regards, Harry.

[JD]

Thanks again Harry.

Always interesting info. I like the way you approach these tests, being a scientist myself, you have a good handle on how to approach these tests. Look forward to seeing more stuff.

FWIW I spent the week with Daisy after easter and we were discussing some of your shooting and testing and a bit of airgunning in general. Nice bloke (well, he'll probably read this so I take that back LOL).

Cheers, JD

[Yrrah]

Thanks JD ....... It's good to get an occasional response, comment or suggestion otherwise it is a bit like talking to one's self and you never know if there is any other out there interested in this way-out stuff. ...........
Yes, Daisy is one of the good guys. We have had a few very enjoyable sessions and more to come I hope.

In case any are interested this is the set-up I am using.

The camera is a Casio EX-FH100 which is a compact but with the feature of being able to take movie at 120, 240. 420 and 1000 frames per sec. The 240 and 420 fps are practical in good light for what I am doing. ... The bracket that attaches to the scope is Seben from Germany and is used for attaching to telescopes and such. In the context in which I am using it the system has been pioneered by a fellow air gunner named Ted in Wisconsin USA.





Best regards, Harry.

[MISSED]

Top Stuff Harry what a great video.I eas not surprised at the corkscrewing just the amount .

Please keep them coming as your posts are very educational

[curan]

G'day all,

If anyones interested, I just bought an adapter the same as Harry's from evilbay.

http://cgi.ebay.com.au/ws/eBayISAPI.dll ... 0290147723.

$42 with free postage. This is the only place I have seen them.

regards, curan

[greyskull]

Harry,
In regards to the damage to tail and head, perhaps the following image can help.



The larger helix tends to be the HEAD damaged pellets, and the smaller helix tends to be the TAIL damaged pellets. Combined, the two helix patterns interact to give us a typical group where both can be identified to be present.



The above target was actually a 55 yard test target of some Chinese pellets sent to me for testing. The head diameter was woefully undersized (4.45mm measured....whereas my barrel only shoots 4.49mm heads with any certainty), and there was some tail skirt damage evident in some pellets.

None were indexed as you would do for your own pellet tests, just randomly loaded as any shooter would usually do. One could mentally superimpose the first duagram onto the second photo quite happily and see what the heck is going on, and why they will not group.

Interesting diagram, when you understand what is going on in flight, thanks to your efforts to educate us all.

GS