Quote Originally Posted by brycelarson View Post
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.
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.