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#1 cockerpunk

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Posted 28 December 2008 - 12:21 PM

data - http://spreadsheets....HdSUAE5ioZ_zbNA

testing rig video -

test video -

thanks to mike video -

discuss!

Edited by cockerpunk, 28 December 2008 - 12:22 PM.

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#2 Lord Odin

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Posted 28 December 2008 - 01:23 PM

Very interesting data. Couple of questions.

1. Do you have specs listed anywhere for the rifled barrels?
2. Do the one piece barrels have the same bore size at the breech as they do at the muzzle? In other words, do they taper along their length and if so, are they the same?
3. The two piece test is rather interesting. There doesn't appear to be a trend amongst the different length barrel fronts. Was there porting on the fronts?
4. What was being tested with the Dye barrels that wasn't covered in the 12" various bores? Is the barrel different?

People have generally recommended 12-14" for a barrel length and its really cool to actually see some numbers to back that up. Looks like they were pretty close.

The 12" front/various back is really interesting. It seems that the paint to barrel match (see top note for paint size) in that instance showed the best efficiency. That's actually opposite of previous bore tests. Any ideas why that may be? Are the freak and CCM kits you guys used in the other tests different from the CP kit?

#3 brycelarson

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Posted 28 December 2008 - 01:30 PM

Very interesting data. Couple of questions.

1. Do you have specs listed anywhere for the rifled barrels?
2. Do the one piece barrels have the same bore size at the breech as they do at the muzzle? In other words, do they taper along their length and if so, are they the same?
3. The two piece test is rather interesting. There doesn't appear to be a trend amongst the different length barrel fronts. Was there porting on the fronts?
4. What was being tested with the Dye barrels that wasn't covered in the 12" various bores? Is the barrel different?

People have generally recommended 12-14" for a barrel length and its really cool to actually see some numbers to back that up. Looks like they were pretty close.

The 12" front/various back is really interesting. It seems that the paint to barrel match (see top note for paint size) in that instance showed the best efficiency. That's actually opposite of previous bore tests. Any ideas why that may be? Are the freak and CCM kits you guys used in the other tests different from the CP kit?


1. Nope, based on the mean velocity we assume they're huge. We tried to measure - but with the rifling it's really hard. Gordon got... I think .689 - but that would most likely be the "peaks" of the rifling.
2. yes - same diameter throughout.
3. yes, check CP's website for a picture - I don't have any. The two piece barrels have two extra rows of porting - otherwise all CP barrels were very similar in porting.
4. Just to throw something else at very similar bore into the test.

As to your last point - we think it's because of how small paint tends to be. Since CP makes a .682 at the smallest we don't feel that we were able to actually underbore all that much.

#4 Promaster928

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Posted 28 December 2008 - 02:05 PM

This is great stuff guys. I can't wait for the accuracy part.

Brycelarson, You mention wanting to underbore more then .682. It seems from your results that the .685 was best size bore to the paint you were shooting which was around .684.

So that would mean the best results came from the barrel being just a little overbored? I'm just trying to better understand all this.

#5 1NOnly

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Posted 28 December 2008 - 04:03 PM

Excellent job! Can't wait for the accuracy portion of the test.

#6 Compulsion

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Posted 28 December 2008 - 04:14 PM

What's with the wicked spiking on those first shots?

In many cases the first shot is 20 or more FPS higher than subsequent shots. Do you have creep in the gun?

This test might benefit from two or three clearing shots before beginning to take measurements. At the very least, remove those outliers from the calculations of Mean and SD.

Edited by Compulsion, 28 December 2008 - 04:17 PM.

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#7 Lord Odin

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Posted 28 December 2008 - 04:56 PM

What's with the wicked spiking on those first shots?

In many cases the first shot is 20 or more FPS higher than subsequent shots. Do you have creep in the gun?

This test might benefit from two or three clearing shots before beginning to take measurements. At the very least, remove those outliers from the calculations of Mean and SD.


That's the beauty of standard deviation. Outliers won't affect the SD as much as it would say mean or range. Picking and choosing which shots to include or exclude isn't a good idea. That can get you into all sorts of problems. Its better to just include all data and analyze it from there. Besides, the bell curve will always have outliers towards the extrema.

That being said, a few clearing shots might be a good precautionary measure. Especially if there are asymptomatic problems with a gun.

#8 brycelarson

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Posted 28 December 2008 - 05:16 PM

Sorry, forgot to note - we knew going in that gordon's emag shoots hot on the first shot after sitting for a while. We wanted a sample size of 20 - so sampled 20 then removed high and low - leaving 20 data points per barrel.

Odin - I'm sure that's why you got different means - the first shot would certainly push the data sets up a few fps.

#9 Compulsion

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Posted 28 December 2008 - 05:26 PM

Picking and choosing which shots to include or exclude isn't a good idea.


You're right, of course. It's unscientific to massage your data.

That being said, a few clearing shots might be a good precautionary measure. Especially if there are asymptomatic problems with a gun.


At least try a few of the tests with a different gun. See if that initial spike persists.

Who knows, the spike is caused by something outside our current model. Maybe there really is something special about the first shot.

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#10 brycelarson

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Posted 28 December 2008 - 05:28 PM

the first shot being hot is standard on gordon's emag - not on any other gun we've tested with. I don't know why - I assume that the valve reg has a little leak allowing the dump chamber to slightly creep up as the gun sits without venting the chamber. one shot and it's back on line - which is why we chose to take 22 samples and dump the high and low.

#11 cockerpunk

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Posted 28 December 2008 - 07:00 PM

dropping the top and bottom value in a set is common practice to remove the outliers.

it works perfectly in this case, we recorded 22 values with each, drop the fastest and slowest, and still have a data set of 20 values.

i am also a bit disappointed to see that we couldn't get a very good underbore going. an odd thing to point out is that in our last test the "matched" did the worst, or worse then over boring anyway, and this test shows the opposite.

me and bryce have a theory as to why, we think.
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#12 Lord Odin

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Posted 28 December 2008 - 07:10 PM

Sorry, forgot to note - we knew going in that gordon's emag shoots hot on the first shot after sitting for a while. We wanted a sample size of 20 - so sampled 20 then removed high and low - leaving 20 data points per barrel.

Odin - I'm sure that's why you got different means - the first shot would certainly push the data sets up a few fps.

Ahh, that would explain the difference in numbers I was seeing. Thanks for clearing that up.

#13 TechPB-Mike

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Posted 28 December 2008 - 07:35 PM

awesome job fellas, holy shit CP hooked some brothers up!!!

Travis you're the MAN!!!

#14 Troy

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Posted 28 December 2008 - 08:13 PM

the first shot being hot is standard on gordon's emag - not on any other gun we've tested with. I don't know why - I assume that the valve reg has a little leak allowing the dump chamber to slightly creep up as the gun sits without venting the chamber. one shot and it's back on line - which is why we chose to take 22 samples and dump the high and low.


I guess if you really wanted to, you could do an outlier Q test, but dropping one high and one low is an acceptable amount of data massaging.
\m/

#15 chewiestmonkey

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Posted 28 December 2008 - 08:25 PM

what would be your guys theory as to why the matched paint to bore worked better this test?

Edited by chewiestmonkey, 28 December 2008 - 08:25 PM.

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#16 AndreS

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Posted 29 December 2008 - 12:25 AM

very nice work!!!



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#17 WihGlah

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Posted 29 December 2008 - 03:45 PM

Sorry - also posted on PBN - and I see Complusion also noticed that the e-mag shoots hot on the first shot

HOWEVER - from a statistical standpoint there is another anomaly:

from the second shot to the 22nd, there is a trend for the velocity to creep up about 20fps.

(for example, the 0.685 one piece 10", shots 2 - 13 are all below the mean, shots 14 - 22 are all above.)

also - 21 shots in a row with an upward trend??

That's not random - and it should be. Something else is going on.

Edited by WihGlah, 29 December 2008 - 03:50 PM.

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#18 brycelarson

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Posted 29 December 2008 - 03:55 PM

automag shoot-up.

#19 Iram

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Posted 29 December 2008 - 04:50 PM

Yeah, an automag may not have been the best choice of guns to test with.

How far back (in inches) is the porting on the CP barrels? Do all the barrels have the same amount of porting?

#20 brycelarson

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Posted 29 December 2008 - 05:02 PM

Yeah, an automag may not have been the best choice of guns to test with.

How far back (in inches) is the porting on the CP barrels? Do all the barrels have the same amount of porting?


our rate of fire on the tests was very consistent - so the effects (if there were any) would have been the same on all barrels - therefore as a comparative test - it's still valid.

WAIT A SECOND! in order to drop the high and low I sorted by lowest to highest - this isn't the shooting order. :)

don't have a barrel in front of me - but about 3" of porting. The porting pattern is identical - except the 2 piece fronts have two extra rows of ports (see pics)

EDIT

I measured:

10" one piece - 10 rows of porting over 3.5"
12", 14", 16" one piece - 12 rows over 4.25"

10" two piece tip - 13 rows over 3.75"
12", 14", 16", 21" - 16 rows over 4.5 inches.

Attached Files


Edited by brycelarson, 29 December 2008 - 05:13 PM.


#21 Iram

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Posted 29 December 2008 - 05:02 PM

How long are the CP backs?

So, looking at the results, I (who suck at statistics) would conclude:

1. Tighter bore = higher velocities.

2. For one-piece barrels, 14" is the ideal length.

3. For two-piece barrels, the length of the tip matters a little, but anything from 10-16" is going to perform about the same. Yeah, they varied, but the differences were all pretty much within the standard deviation. With things that close, personal preference (ergonomics) is probably more important when actually playing paintball.

Any ETA for the results of your accuracy tests? I'm planning to buy a new barrel based on the final results of these tests, and I was hoping to have that show up on my December budget instead of January.

EDIT: Bryce, I just saw your response about the sorting. That makes a lot of sense.

Edited by Iram, 29 December 2008 - 05:03 PM.


#22 Poe

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Posted 29 December 2008 - 05:06 PM

automag shoot-up.


Since these tests are using velocity change as the measured variable, shouldn't a marker that doesn't have velocity issues be used? Maybe an Ion with max dwell?

I'm assuming the main point of the barrel length tests was to determine if barrel length effected consistency? Each marker has a barrel length that is most efficient for its setup. Might want to put a disclaimer here so no one thinks a 14" barrel is most efficient on their gun... unless they have the same exact Emag setup.

Did all barrels have the same exact porting? What was the distance from the barrel tip to the start of the porting?

Was paint to barrel match .683?

Adjusting for the mag's shoot-up, it looks like length had a negligible effect on velocity consistency.

#23 brycelarson

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Posted 29 December 2008 - 05:21 PM

automag shoot-up.


Since these tests are using velocity change as the measured variable, shouldn't a marker that doesn't have velocity issues be used? Maybe an Ion with max dwell?

I'm assuming the main point of the barrel length tests was to determine if barrel length effected consistency? Each marker has a barrel length that is most efficient for its setup. Might want to put a disclaimer here so no one thinks a 14" barrel is most efficient on their gun... unless they have the same exact Emag setup.

Did all barrels have the same exact porting? What was the distance from the barrel tip to the start of the porting?

Was paint to barrel match .683?

Adjusting for the mag's shoot-up, it looks like length had a negligible effect on velocity consistency.


answers to most of these have been posted - read a few posts up.

paint to barrel match was pretty small - depending on the ball somewhere around .685. So, in this test we were not able to achieve the level of underbore we did in previous tests. That said, the bore portion of this test pretty much lined up with what we got last time. The new analisys available with this test is the length and one v two piece design.

Based on this testing - I DO think that a 14" small bore barrel will be the most efficient on any gun.

The emag we used on this test achieved a SD of under 2 fps on previous tests with a sample size of 20 - it's a fantastic, consistent shooting gun - and as I posted above - the reason the data is in ascending order is that I sorted it that way to knock off the highest and lowest.

#24 scc2052

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Posted 29 December 2008 - 05:47 PM

In the results I'm confused and don't really understand what the numbers on the graphs that are on they left mean can someone help me out? thanks
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#25 brycelarson

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Posted 29 December 2008 - 06:11 PM

In the results I'm confused and don't really understand what the numbers on the graphs that are on they left mean can someone help me out? thanks


the two numbers that we're looking at for this test are:

mean velocity

and

SD (standard deviation)

mean velocity is a number that tells you how fast the ball was leaving the barrel. A higher mean velocity indicates that with the gun set the same - that barrel is going to shoot faster. This indicates that you could get more shots at a specific velocity from the same tank out of a barrel with a higher mean velocity.

Standard Deviation (SD) is an indication of how consistent that barrel is. the lower the number the more consistent. A low SD will directly correlate to having a lower +/- fps when chronoing a gun. Additionally, it's my assumption that a more consistent gun will be a more accurate one.

does that help?

#26 Poe

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Posted 29 December 2008 - 08:38 PM

It might also be worth noting the porting when referring to a barrel length as 'most efficient'. Wouldn't you have to test more then one gun to make that claim though? Try just shooting the emag with a higher or lower internal pressure and I'll bet you get a different 'most efficient' length. Maybe do a string of 'hot' shots by pausing between shots so the dump chamber can reach ambient.

The emag might be consistent with one type of barrel and paint, but as shown in the "dry fire vs paint efficiency test" backpressure can effect it's operation for better or worse.

Thanks for noting the sorting. That was really throwing me off. :)

#27 cockerpunk

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Posted 29 December 2008 - 11:45 PM

It might also be worth noting the porting when referring to a barrel length as 'most efficient'. Wouldn't you have to test more then one gun to make that claim though? Try just shooting the emag with a higher or lower internal pressure and I'll bet you get a different 'most efficient' length. Maybe do a string of 'hot' shots by pausing between shots so the dump chamber can reach ambient.

The emag might be consistent with one type of barrel and paint, but as shown in the "dry fire vs paint efficiency test" backpressure can effect it's operation for better or worse.

Thanks for noting the sorting. That was really throwing me off. :)


if the goal however is pure shot to shot consistency that gun is so far the best gun i have ever seen in my 9 years now of playing paintball. it is simply amazing over the chrono. seriously, i have seen and shot them all, from AKA to DM and such, and that emag is amazing over the chrono. it is unquestionably the most consistent gun i have ever laid hands on. it beats my cyborg by at least 50%. the dry fire vs with paint does little in comparison to shot to shot consistency, that is a test that deals primarily with the pressure in the dump chamber when cycling normally, which, as long as the gun shoots consistent doesn't matter one bit.

would it have been easier that we simply shoot 3 times before each test and not record it? to me, it makes alot more sense to have a standard procedure like droping the high and low, a STANDARD manipulation of data widely accepted in experimental dings.

porting and length of back are factors, i'd agree there. the CP backs looked to me to be 4 or 5 inches long, but we can see the effect of 12, 14, and 16 inch "control bores" with the one piece test.

Edited by cockerpunk, 29 December 2008 - 11:47 PM.

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And yes, Gordon is the sexiest manifestation of "to the front."


#28 slinkyaroo

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Posted 29 December 2008 - 11:46 PM

CP - what paint were you testing at the time? What bore size was the paint?



.

#29 Lord Odin

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Posted 29 December 2008 - 11:48 PM

CP - what paint were you testing at the time? What bore size was the paint?



.


They noted the paint in the top left corner of the data spreadsheet. It was DXS Silver with a .683-.684 bore size.

#30 kert.

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Posted 30 December 2008 - 09:17 AM

For more accurate 1-piece vs 2-piece comparsion, shouldn't you test with .685 back?

Awesome job tho! :tup:
Thanks!

#31 brycelarson

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Posted 30 December 2008 - 09:44 AM

It might also be worth noting the porting when referring to a barrel length as 'most efficient'. Wouldn't you have to test more then one gun to make that claim though? Try just shooting the emag with a higher or lower internal pressure and I'll bet you get a different 'most efficient' length. Maybe do a string of 'hot' shots by pausing between shots so the dump chamber can reach ambient.

The emag might be consistent with one type of barrel and paint, but as shown in the "dry fire vs paint efficiency test" backpressure can effect it's operation for better or worse.

Thanks for noting the sorting. That was really throwing me off. :)


No, we don't have to test more than one gun to make the efficiency claim. A gun is a valve - how that valve gets air into the barrel is WAY less important than how the air interacts as the ball is accellerating.

I do see what you're getting at - maybe a steep slope on the power pulse would result in a shorter optimal barrel length? Maybe. However, the way a gun delivers air isn't going to radically effect optimal barrel length. On the Emag it's 14" Maybe we'll shoot the Cyborg on Friday and test 10, 12, 14, 16 again. Wouldn't take long - but I'm willing to lay money on the same results. Whatever the gun's power pulse looks like the ball is going from 0 fps to 300 fps in a very, very short time - and the distances that it takes to get to that speed are going to be very similar on all guns.

sorry about the sorting - I should have noted that from the begining :)


For more accurate 1-piece vs 2-piece comparsion, shouldn't you test with .685 back?


we did.

#32 Lord Odin

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Posted 30 December 2008 - 10:30 AM

It might also be worth noting the porting when referring to a barrel length as 'most efficient'. Wouldn't you have to test more then one gun to make that claim though? Try just shooting the emag with a higher or lower internal pressure and I'll bet you get a different 'most efficient' length. Maybe do a string of 'hot' shots by pausing between shots so the dump chamber can reach ambient.

The emag might be consistent with one type of barrel and paint, but as shown in the "dry fire vs paint efficiency test" backpressure can effect it's operation for better or worse.

Thanks for noting the sorting. That was really throwing me off. :)


No, we don't have to test more than one gun to make the efficiency claim. A gun is a valve - how that valve gets air into the barrel is WAY less important than how the air interacts as the ball is accellerating.

I do see what you're getting at - maybe a steep slope on the power pulse would result in a shorter optimal barrel length? Maybe. However, the way a gun delivers air isn't going to radically effect optimal barrel length. On the Emag it's 14" Maybe we'll shoot the Cyborg on Friday and test 10, 12, 14, 16 again. Wouldn't take long - but I'm willing to lay money on the same results. Whatever the gun's power pulse looks like the ball is going from 0 fps to 300 fps in a very, very short time - and the distances that it takes to get to that speed are going to be very similar on all guns.

sorry about the sorting - I should have noted that from the begining :)


Hmmm. Shouldn't an LP gun require a longer barrel than an HP gun? After all, its using less pressure but requires more volume. Wouldn't that necessitate a longer barrel to accelerate the ball up to field velocity? I would think that an HP gun accelerates the ball in a shorter distance and wouldn't require as long of a barrel. If that's true, perhaps you should repeat the test with an opposite pressure gun. I don't know if the Emag is HP or LP. Or do you think that the barrel length difference is negligible?

Edited by Lord Odin, 30 December 2008 - 10:31 AM.


#33 Snipez4664

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Posted 30 December 2008 - 11:09 AM

Those differences mostly get washed out in the valving, before the ball sees them. What we're really concerned with is the 'shape' of the power pulse that hits the ball - acceleration is part of this shape and the pressure tends to build much faster than the ball is accelerated - I would tend to disagree with bryce that the length will be totally independent of gun - think about it:

For a given efficiency gun, you need X amount of pressure*volume work to get to field velocity.

The point at which you get diminishing returns on the barrel length is where the pressure*area of a paintball is less than drag + friction. Generally this will occur at a given system volume, where the system is barrel + dump chamber+ pre-expansion volume. Note that for poppet guns or anything sealing the chamber, the dynamics get even more complicated and must be modeled in at least 2 steps.

I'd expect poppet guns to benefit from a shorter barrel, and spools to benefit from longer ones. The automag somewhat splits the difference (Tiny dump chamber spool). Welcome to my gross oversimplification.
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#34 cockerpunk

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Posted 30 December 2008 - 12:39 PM

I'd expect poppet guns to benefit from a shorter barrel, and spools to benefit from longer ones. The automag somewhat splits the difference (Tiny dump chamber spool). Welcome to my gross oversimplification.


haha

so, do you think thats a large enough effect to notice? like measure in inches?

idk, i see theoretically where you are going, but i just dont think it will have a very large effect.

i would expect the porting pattern and whatnot to have a larger effect, for example. we saw that there was similarities with the dye barrels compared to the CP ones, even though they are ported and built differently. at the same time we saw some slight differences.
The ultimate truth in paintball is that the interaction between the gun and the player is far and away the largest factor in accuracy, consistency, and reliability.

And yes, Gordon is the sexiest manifestation of "to the front."


#35 Snipez4664

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Posted 30 December 2008 - 01:26 PM

so, do you think thats a large enough effect to notice? like measure in inches?


Hrm. OTOH, Glenn Palmer says it does. I remember him claiming he matches barrels to guns individually.

A barrel gives you what, 0.37 cubic inches per inch linear?

and you need, say, 115 in-lbs to fire the ball...that means a 150psi gun's dump chamber is what, 1 inch cubic, perhaps? I feel like that puts about a 3 inch cap as far as variance on the whole thing. I think it's probably one of those things that you could confirm with the right experiment, but it might now fall out naturally of others...Meaning as far as scale goes, we don't really care.
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#36 paulpker121

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Posted 30 December 2008 - 01:48 PM

Wow, this further proves that underboring > overboring!

You guys have come a long way, congratulations on the sponsorships.

#37 brycelarson

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Posted 30 December 2008 - 06:06 PM

Hmmm. Shouldn't an LP gun require a longer barrel than an HP gun? After all, its using less pressure but requires more volume. Wouldn't that necessitate a longer barrel to accelerate the ball up to field velocity? I would think that an HP gun accelerates the ball in a shorter distance and wouldn't require as long of a barrel. If that's true, perhaps you should repeat the test with an opposite pressure gun. I don't know if the Emag is HP or LP. Or do you think that the barrel length difference is negligible?


the emag is HP - BUT, and this is a big but, operating pressure has very little to do with breech pressure. Breech pressure is more dependent on valve design.

We could certainly put a LP spoolie up against a HP poppet and see if barrel length changes. That would be an easy basement test. dunno if we'll have time to add it to Friday - we're already going to be busy.

#38 romulus333

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Posted 30 December 2008 - 07:14 PM

What's with the wicked spiking on those first shots?

In many cases the first shot is 20 or more FPS higher than subsequent shots. Do you have creep in the gun?

This test might benefit from two or three clearing shots before beginning to take measurements. At the very least, remove those outliers from the calculations of Mean and SD.


That's the beauty of standard deviation. Outliers won't affect the SD as much as it would say mean or range. Picking and choosing which shots to include or exclude isn't a good idea. That can get you into all sorts of problems. Its better to just include all data and analyze it from there. Besides, the bell curve will always have outliers towards the extrema.

That being said, a few clearing shots might be a good precautionary measure. Especially if there are asymptomatic problems with a gun.


I would second that discarding outliers is problematic for validity, but using a certain number of clearing shots as a pretest operation would be a methodologically sound idea.

#39 Iram

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Posted 30 December 2008 - 07:15 PM

What is the operating pressure on that emag?

#40 brycelarson

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Posted 30 December 2008 - 07:50 PM

I would second that discarding outliers is problematic for validity, but using a certain number of clearing shots as a pretest operation would be a methodologically sound idea.


the highest was the first shot in every round of shooting and is listed first on each data set - if you want to crunch the numbers simply dropping the first shot - the data's ready to do that as well.

in fact, I just did that - the mean fps dropped a bit - the SD rose a bit - but consistently on all.

all rankings remain the same.


What is the operating pressure on that emag?


CockerPunk can answer better than I can - but I think 650 / breech pressure somewhere around 80

Edited by brycelarson, 30 December 2008 - 08:04 PM.


#41 scc2052

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Posted 30 December 2008 - 08:20 PM

In the results I'm confused and don't really understand what the numbers on the graphs that are on they left mean can someone help me out? thanks


the two numbers that we're looking at for this test are:

mean velocity

and

SD (standard deviation)

mean velocity is a number that tells you how fast the ball was leaving the barrel. A higher mean velocity indicates that with the gun set the same - that barrel is going to shoot faster. This indicates that you could get more shots at a specific velocity from the same tank out of a barrel with a higher mean velocity.

Standard Deviation (SD) is an indication of how consistent that barrel is. the lower the number the more consistent. A low SD will directly correlate to having a lower +/- fps when chronoing a gun. Additionally, it's my assumption that a more consistent gun will be a more accurate one.

does that help?


yes thank you very much great job with your test very well put together thanks again
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#42 Poe

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Posted 31 December 2008 - 10:37 AM

...
Standard Deviation (SD) is an indication of how consistent that barrel is. the lower the number the more consistent. A low SD will directly correlate to having a lower +/- fps when chronoing a gun. Additionally, it's my assumption that a more consistent gun will be a more accurate one.
...


I realize it's a lot to ask, but will the individual velocity and impact location of each ball be charted during accuracy tests? Would be interesting to see how much accuracy is effected by velocity fluctuations. Maybe that's one for another test?

#43 Lord Odin

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Posted 31 December 2008 - 10:41 AM

Since the gun is going to be clamped down, I don't see why it couldn't be chrono'd as well. To see if there is a direct correlation, it would be suggested to record the velocity and its hit location together. I wouldn't separate those two values through sorting or exclusion as they may be linked.

#44 Snipez4664

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Posted 31 December 2008 - 11:01 AM

Since the gun is going to be clamped down, I don't see why it couldn't be chrono'd as well. To see if there is a direct correlation, it would be suggested to record the velocity and its hit location together. I wouldn't separate those two values through sorting or exclusion as they may be linked.


Especially if you have an estimate for what the drop should be based on velocity - use the excellent paintball trajectory calculator for that. That way, each shot can be normed to it's own zero - interesting when you're only investigating, say, the effect a barrel has, independent of gun.

It's a pain to send one man downrange while the other shoots, but damn...it would be interesting.
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#45 cockerpunk

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Posted 31 December 2008 - 11:18 AM

we will be re-chonoing the gun in the XY grid test. i dont know if we will chrono each shot in that test, we have alot to do that day, so we might just make sure they are all shooting in a certain range before testing.

Edited by cockerpunk, 31 December 2008 - 11:25 AM.

The ultimate truth in paintball is that the interaction between the gun and the player is far and away the largest factor in accuracy, consistency, and reliability.

And yes, Gordon is the sexiest manifestation of "to the front."


#46 Snipez4664

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Posted 31 December 2008 - 11:32 AM

we will be re-chonoing the gun in the XY grid test. i dont know if we will chrono each shot in that test, we have alot to do that day, so we might just make sure they are all shooting in a certain range before testing.


Sounds good - a consistent enough gun is plenty enough control IMO.
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#47 brycelarson

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Posted 31 December 2008 - 12:28 PM

last time with the backspin test we got fps, x, y data on all shots - don't see why we can't on this one as well

I intended to do that.

#48 cockerpunk

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Posted 31 December 2008 - 12:43 PM

id like to do that to, i think that will give us the final word on using chronograph readings to compare to actual XY accuracy.

id also like to do the accuracy VS fps test that day too.

Edited by cockerpunk, 31 December 2008 - 01:05 PM.

The ultimate truth in paintball is that the interaction between the gun and the player is far and away the largest factor in accuracy, consistency, and reliability.

And yes, Gordon is the sexiest manifestation of "to the front."


#49 brycelarson

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Posted 31 December 2008 - 03:30 PM

id also like to do the accuracy VS fps test that day too.


yup, I assumed we would use the best barrel from the accuracy at 275 test - then shoot at say 220, 240, 260, 280, 300 and 320 and see what happens.

#50 Poe

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Posted 31 December 2008 - 03:47 PM

Fantastic. Best of luck.
:)




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