Find fields & stores near you!
Find fields and stores
Zipcode
PbNation News
PbNation News
Community Focus
Community Focus

Reply
 
Thread Tools
Old 06-23-2008, 07:17 PM #1
brycelarson
 
 
brycelarson's Avatar
 
Join Date: Apr 2007
Location: Minnesota
barrel test v 2.0

Hey everyone, CockerPunk and I did another barrel test.

I became curious while reading Mann's barrel test on PBN about a few things.

1. What sizer is optimal for a particular ball
2. What effect does drastic over and under boring have on efficiency and consistency

Our test rig was the following:
* emag
* shooting chrony (accurate to %99.5)
* 500 anarchy paintballs (pretty fresh mid-grade paint)
* bucket

I shot 20 shots through the chrony from each of the following:
* freak kit (12 inches with teardrop front) all 10 inserts - we had a couple of duplicate sizes
* CCM carbon fiber kit - 5 backs
* 4 random cocker threaded barrels we had sitting around including 2 identical Dye 12" aluminum boomsticks

We recorded velocity from each and the results are posted in the following spreadsheet:

http://spreadsheets.google.com/pub?k...sMngwmAygIkHfQ

Our results indicate that the smallest barrels / inserts / backs had both the highest average velocity and the lowest standard deviation. This test would indicate to me that if given the choice under-boring is your best bet.

I don't know the implications for barrel break increases with fast shooting - that would take another pile of paint and some more testing.
__________________
-Bryce Larson
b_teeth@yahoo.com
brycelarson is offline   Reply With Quote
Old Sponsored Links Remove Advertisement
Advertisement
Old 06-23-2008, 07:50 PM #2
cockerpunk (Banned)
Show Me the Data
 
cockerpunk's Avatar
 
Join Date: Nov 2003
Location: Nowhere near Sparta
 has been a member for 10 years
heres my take on the test we did -

indeed, it seems that "perfect" paint to barrel match is actually the worst from a performance aspect.

heres our theory about why -

when you overbore, the ball rarely, or at least touches the barrel less, and thus, the variation in size from paintball to paintball means less. this means that air leaks around it (thus the worse efficiency), but also that the gun is more consistent due to a more consistent force from the barrel on the ball. more accurately, the variation in size of the ball does not have a huge effect on the force the barrel imparts on the ball (both directionally and velocity wise).

when you under bore, obviously you get more shots per tank, becuase less air leaks out. and the barrel imparts a consistent force becuase every single ball is to large, and thus the force is more constant. again, the variation in shape and size of the paintball has less effect on the force the barrel imparts becuase all the balls are being squished more or less equally.

and it seems that "ideal" paint to barrel match is not ideal in the least. you have to pay the efficiency cost from the air leakage, and you get inconsistent forces from the barrel becuase some of the balls touch more than others.

so, from this it seems that a bit underbored is probably the best, but a bit operbored is almost as good. both monster over and under bored hurts performance, and as stated before, "perfect" is the worst of both worlds.

yes, a barrel break test might just be in the works when we talk about underboring.
cockerpunk is offline   Reply With Quote
Old 06-23-2008, 08:05 PM #3
AggiePBaller
Go Aggies! Whoop!
 
AggiePBaller's Avatar
 
Join Date: Aug 2007
Location: College Station, Texas
AggiePBaller donated to help Peyton Trent
Very interesting. It make sense once you stop to think about it. If paintballs were the exact same size then paint/bore match would be the best, but since they aren't in the real world neither is paint/bore match. guys
__________________
Have you checked the FAQ?
"Give me an army of West Point graduates, I'll win a battle. Give me a handful of Texas Aggies and I'll win a war!" -Gen. Patton
"Nothing gives one person so much advantage over another as to remain always cool and unruffled under all circumstances." -Thomas Jefferson
"Fast is fine, but accuracy is everything" -Wyatt Earp
AggiePBaller is offline   Reply With Quote
Old 06-23-2008, 09:22 PM #4
Fubarius
Yep, it's orange.
 
Fubarius's Avatar
 
Join Date: Aug 2003
Location: New Richmond, WI
Annual Supporting Member
 has been a member for 10 years
Fubarius supports our troops
Fubarius has achieved Level 1 in PbNation Pursuit
Fubarius has achieved Level 2 in PbNation Pursuit
Fubarius is a Forum Captain
I'd like to see another ranged test for accuracy with the different bore sizes. In my experience with extreme overboring you get a wider shot pattern compared to a medium match or slight overbore. My hypothesis would be that the excessive overbore would allow slightly different exit vectors. I.E. ball flying low in the bore one shot, high in the bore the next, off to the side the shot after that. Of course that's just a hypothesis, for which I'll eventually get around to testing (working on a bench gun just for questions like that).
Fubarius is offline   Reply With Quote
Old 06-23-2008, 09:28 PM #5
cockerpunk (Banned)
Show Me the Data
 
cockerpunk's Avatar
 
Join Date: Nov 2003
Location: Nowhere near Sparta
 has been a member for 10 years
accuracy is a gonna be tricker, but i have a few ideas.

however, going back to what we and other have tested, a gun that is consistent in velocity and does not impart a spin on the ball will shoot accurately.
cockerpunk is offline   Reply With Quote
Old 06-23-2008, 09:32 PM #6
Fubarius
Yep, it's orange.
 
Fubarius's Avatar
 
Join Date: Aug 2003
Location: New Richmond, WI
Annual Supporting Member
 has been a member for 10 years
Fubarius supports our troops
Fubarius has achieved Level 1 in PbNation Pursuit
Fubarius has achieved Level 2 in PbNation Pursuit
Fubarius is a Forum Captain
Well, for an accuracy test I think we'll have to stop thinking of the gun as a paintball gun. Slap a scope on that thing and aim for a spot. It won't hit the spot of course (we're not expecting it too), but we'll know that the barrel is pointing at the same spot each time we fire. Fire a couple hundred shots and measure the pattern. Or we could clamp it in place and be very careful not to move it between shots, but it would take a lot of measurements to make sure it's in the same place when we have to take it down to make changes to the setup.
Fubarius is offline   Reply With Quote
Old 06-23-2008, 09:39 PM #7
cockerpunk (Banned)
Show Me the Data
 
cockerpunk's Avatar
 
Join Date: Nov 2003
Location: Nowhere near Sparta
 has been a member for 10 years
Quote:
Originally Posted by Fubarius View Post
Well, for an accuracy test I think we'll have to stop thinking of the gun as a paintball gun. Slap a scope on that thing and aim for a spot. It won't hit the spot of course (we're not expecting it too), but we'll know that the barrel is pointing at the same spot each time we fire. Fire a couple hundred shots and measure the pattern. Or we could clamp it in place and be very careful not to move it between shots, but it would take a lot of measurements to make sure it's in the same place when we have to take it down to make changes to the setup.
well, we would simply vice the guns, and shoot them though paper.

making the paintballs break on a piece of wood or whatever is incredibly dirty, yucky, very messy. and worse, measuring the results will be very hard too, as each paintball puts a nice 2 or 3 inch mark on there, all on top of each other and such.

yes, i have done an accuracy test like that before ... i know how much of a pain that stuff can be.

however, i am gonna stick by what i had posted before, even with a "backspin" bolt, we could not a get a gun to put enough spin on a ball to change its flight any, so spin in clearly not an issue. that leaves consistency, which we have tested here.
cockerpunk is offline   Reply With Quote
Old 06-23-2008, 09:53 PM #8
Fubarius
Yep, it's orange.
 
Fubarius's Avatar
 
Join Date: Aug 2003
Location: New Richmond, WI
Annual Supporting Member
 has been a member for 10 years
Fubarius supports our troops
Fubarius has achieved Level 1 in PbNation Pursuit
Fubarius has achieved Level 2 in PbNation Pursuit
Fubarius is a Forum Captain
Oh, I'm not talking about spin, I'm talking about exit vector. Literally the ball flying is a slightly different direction. No spin, same velocity, but hitting a different spot.

Check out this simple exagerated drawing...


On the top, the ball closely fits the barrel, so it can only exit on a single vector.

On the bottom, the ball is dramatically undersized, so it has a wide range of directions it can leave the barrel.

This is of course just a hypothesis, but it could explain why my very consistant regulated blowforward T9, with a .693 barrel shooting .685 paint seems to shoot a wider pattern than my freak barrel matched unregulated blowback alley cat. Could be optical illusion as well, or possibly barrel quality of the T9, or the tripple stage bore on the T9 compared to the dual stage bore on the freak. Who knows, but that's what testing is for of course. Good old science. Throw out a hypothesis, test to prove or disprove, repeat.
Fubarius is offline   Reply With Quote
Old 06-24-2008, 11:29 AM #9
jshaft37
 
 
jshaft37's Avatar
 
Join Date: Aug 2007
great work again guys. hopefully, people will read this one too. you guys are actually applying science to real life applications, whereas most people just tend to dispel logic and go by what they thought they saw. as an engineer, i certainly appreciate what you guys are doing and can't wait for the accuracy test.
jshaft37 is offline   Reply With Quote
Old 06-25-2008, 11:32 AM #10
tEh PwNz1c0r
 
 
tEh PwNz1c0r's Avatar
 
Join Date: Oct 2007
Is there supposed to be a sheet 2 and 3? It won't let me view it. But, yeah, great work.

I think this underboring idea is very interesting, although I would only try it with recreational grade paint. Too much stress on tournament paint trying to squeeze into the barrel would cause a lot of breaks.
tEh PwNz1c0r is offline   Reply With Quote
Old 06-25-2008, 04:07 PM #11
Gravedigg154
 
 
Gravedigg154's Avatar
 
Join Date: Jul 2007
Quote:
Originally Posted by AggiePBaller View Post
Very interesting. It make sense once you stop to think about it. If paintballs were the exact same size then paint/bore match would be the best, but since they aren't in the real world neither is paint/bore match. guys
Regulating would help but theirs no way to make each paintball the exact same size.
Gravedigg154 is offline   Reply With Quote
Old 06-25-2008, 10:39 PM #12
leftystrikesback
 
 
leftystrikesback's Avatar
 
Join Date: Mar 2008
Location: San Diego
Very nice test, would be helpful to post this in the barrels forum too.

What size was the paint used (actual size)? I didn't see in on the sheet and it would help interpret the results.
leftystrikesback is offline   Reply With Quote
Old 06-25-2008, 11:32 PM #13
brycelarson
 
 
brycelarson's Avatar
 
Join Date: Apr 2007
Location: Minnesota
the paint matched the blow-through test on the .687 insert - which CP measured and which was within a few thousandths of an inch
__________________
-Bryce Larson
b_teeth@yahoo.com
brycelarson is offline   Reply With Quote
Old 07-14-2008, 09:05 PM #14
ineasyi
 
 
ineasyi's Avatar
 
Join Date: Jul 2007
Location: Burlington
wow this thread is awsome!
__________________
Head shots are the best shots

DP G3(black), DP F8(Blue/Silver)

velocity w/speedfeed, Sly barrel kit, 70/45 tank

ineasyi is offline   Reply With Quote
Old 07-14-2008, 09:21 PM #15
brycelarson
 
 
brycelarson's Avatar
 
Join Date: Apr 2007
Location: Minnesota
Quote:
Originally Posted by ineasyi View Post
wow this thread is awsome!
thanks, CP and I are just trying to do a service to the PB community
__________________
-Bryce Larson
b_teeth@yahoo.com
brycelarson is offline   Reply With Quote
Reply


Thread Tools

Posting Rules
Forum Jump