Paintball

[cockerpunk]

hell, all im gonna do is a 99% percent confedence interval T test, so if anyone else who knows a bit about stats wants to do them - you already have the data.

taht should show conclusivly what is and what is not statistically significant.

[cockerpunk]

99% confidence interval graphs -

note - the backspin and non-backspin means are connected with lines. the upper and lower points are the limits of population mean confidence, and the unconnected dot in the center is the sample mean with those variables. Excel was not being friendly, and i could not graph them exactly how i would have liked to.







other pics of note -











if you want to know what i think, and my conclusions, just let me know.

[brycelarson]

That's Chris Nathan shooting - he's the one that donated the space. That's me with the red glass.

[Chris Nathan]

The rig used in this experiment is very easy to replicate and I have a total of 160' feet to work with in the shop so we are planning on trying again later on at 100'. I was hoping for a more pictorial representation of the results as you could very distinctly see a pattern in the shots based on velocity. It would be very interesting as I could tell if a shot was within velocity range based on where it hit before Bryce read the chrono. I don't think 50' is far enough to really judge whether or not a cooper t bolt works or not.

[drg]

If I am reading the results correctly, the result is that indeed the backspin bolt does *something* but it may not be consistent enough (due to a number of factors) to be valuable in and of itself.

If that's the case then this matches the results, albeit anecdotal, that pump and I got with our tests with the Cooper T bolt a few days after the original thread blew up. We did not measure them but we could tell the bolt was doing *something*, just not anything we could depict well on video, nor were we using a setup that lent itself to scientific measurement.

It definitely can change the trajectory of the ball, but it would seem that you need something more radical to get a truly significant difference consistently.

[russc]

It would be interesting if you could just turn off all the lights, set a digicam up with a longish exposure perpendicular to the trajectory, and backlight the ball to capture the flight lines. It may not be scientific but I think it would give a nice visual reference to any trajectory changes.

[cockerpunk]

Originally Posted by drg

If I am reading the results correctly, the result is that indeed the backspin bolt does *something* but it may not be consistent enough (due to a number of factors) to be valuable in and of itself.

If that's the case then this matches the results, albeit anecdotal, that pump and I got with our tests with the Cooper T bolt a few days after the original thread blew up. We did not measure them but we could tell the bolt was doing *something*, just not anything we could depict well on video, nor were we using a setup that lent itself to scientific measurement.

It definitely can change the trajectory of the ball, but it would seem that you need something more radical to get a truly significant difference consistently.

indeed, i agree.

the intervals show rather conclusively in all but the very weird case with the matched paint, that the error in the experimental setup was of larger effect than the any of the bolts we tested.

and (assuming 50 feet is long enough, which i agree chris, may not be), this rig more than removed all reasonable factors of error with far greater precision than one could ever replicate or use on the paintball field.

even the bolt that showed a statistical difference from all the others showed only 2 inches, and IMO that is not enough when considering standard field usage. and it is certainly less than the extra 50 feet or 100 feet some (the guy selling them on AO anyway) claim.

[Tohri]

I'm curious as to the relationship between Backspin bolts and Flatline/Apex barrels. Perhaps that can be your nrext round of testing.

Also, I seriously wonder what peak pressure has to do with these different testings. Tom kaye looked into peak pressure as a definite source of barrel breakage in the mid nineties, if I'm not mistaken. Something like Mags and cockers had the highest Peak pressures, and Shockers and Tippmanns had the lowest or something.

[brycelarson]

Originally Posted by Tohri

I'm curious as to the relationship between Backspin bolts and Flatline/Apex barrels. Perhaps that can be your nrext round of testing.

Also, I seriously wonder what peak pressure has to do with these different testings. Tom kaye looked into peak pressure as a definite source of barrel breakage in the mid nineties, if I'm not mistaken. Something like Mags and cockers had the highest Peak pressures, and Shockers and Tippmanns had the lowest or something.

I think you're mis-remembering - the mag was actually pretty low. It has a high operating pressure - but had lower or equal breech pressure. This was his attempt to combat the marketing hype surrounding low pressure guns.

Automags.Org Online Forums - Official Data Thread

emag was 60 psi, angel was 100, cocker was 110.

[cockerpunk]

i am still puzzling though how a matched barrel seems to work better than an overbore. if anyone has any theories i am certainly open to discussion. i have an idea, and im gonna look though the numbers again before posting it.