Underbore / Overbore question

digitalman

Well-Known Member
Apr 21, 2011
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Uckfield East Sussex
I've read on these forums about under and over boring instead of bore matching to get better accuracy during games. Of course non of these methods will work when dodgy paint is used, but all the information i have found has always just talked generally about going bigger or smaller on the bore size without being specific on how big or how small to go.

So the question is I have 3 markers that all have an autococker threaded barrel and plenty of different sized barrels and an Evil pipe kit. The markers are an Ego 8, a MacDev Cyborg and my trusty old Eblade autococker just incase this effects what bore pipe to use. Assuming that the paint is of a good quality and of a middle size, should I go one or two sizes larger or smaller depending if I want to try over or under boring?
 

Canon Fodder

Go to your brother, kill him with your gun.
Oct 28, 2008
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For the eblade underbore one size if it dry, bore match if its damp, if you overbore the paint will roll out. For the Ego and MacDev overbore one size up.
 

digitalman

Well-Known Member
Apr 21, 2011
411
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Uckfield East Sussex
Ok I can see why to underbore on the autococker, but why overbore on the Ego and Cyborg?

Since having the pipe kit and collecting other various autococker threaded barrels I always have done a blow test, but always picked the best fit rather than going smaller or larger.
 

Canon Fodder

Go to your brother, kill him with your gun.
Oct 28, 2008
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Lancaster
Some fairly extensive research has suggested that an overbore leads to more consistent velocities, I suppose its because paint is not actually a consistent size so with bore match you're sometimes overboring, sometime under boring. If you want facts and figures the "punk works" section of techpb.com has a few sets of data.
 

Magic_Ernie

Active Member
Jun 11, 2009
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I usually overbore on my Ego 8 with CF boomstick. Not much though, under boring always leads to barrel breaks for me.
 

Niall W

Platinum Member
Dec 13, 2007
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Cambridgeshire / Swansea
Another reason to overbore, as i've always understood it, is it means just buying one barrel / non stock back instead of shelling out for a kit :)
 
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Liam92

#16 Reading Entity
Nov 4, 2009
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Glasgow, Scotland
overbore = poor efficiency, good consistency
underbore = good efficiency, good consistency. debatable that it causes more breaks but never conclusively proven.
paint to barrel match = poor efficiency, poor consistency.

take your pick from them.