Best way to find correct bore size

Pson · 10-01-2012, 08:30 AM

I currently have the following setup and trying to learn more in the way of barrels (matching boring).

Current setup:
AXE 2012, Boss bolt (Yellow spring), Freak Barrel kit (.684 SS) 68/45 DXS air.

Field paint:
Heat (pink color and only use this for now).

Blow test seems to give me the following results...(.684) 5 out of 6 goes 3/4 of the insert and then needs to be blown out (best per freak info). The 1 out of 6 will either is overbored or underbored (really is random, super tight to start or falls right past insert). When I shoot my axe most shots are good, but a few have a willd twist on them (making the shot about 5 yards left or right). Reading all the posts on the forum, it seems underbore is the best and wonder how you find the right combo?

SNAKESNIPER (Banned) · 10-01-2012, 08:40 AM

Most paint these days bores out between .682 - .685 (I've even heard of rollouts through a .678). With that in mind, a .684 is really a paint-to-bore match, which is inherently inconsistent due to the size fluctuations with the paint itself. In the span of one hopperful of paint you might have balls in series where a few will be undersized, the next few could be oversized, a few could be oblong, etc etc etc. Now picture all of those escaping a single bore size that ALMOST matches all of them but not quite, and you can see how you would get inconsistent chrono readings.

This is why I believe that an underbore of .682 or less produces optimal consistency; because ALL size fluctuations will be larger than the bore. In effect, the control bore provides a "stop point" where the paint is squeezed and exits the barrel at a more uniform speed.

Someone else can probably explain this more eloquently than I just did, but the bottom line is to get an underbore barrel around .678-.682 and you'll see more consistent chrono readings. BTW when you're doing a blow test, a proper underbore won't allow you to blow paint through very easily, it will require a LOT of force.

Pson · 10-01-2012, 09:34 AM

Interesting comments and thank you for that too. I might have to plaay around with that and see what happens. What does the balls does under underboring? Meaning fly strighter with more power or will the paint also have a twist or spin to it?

Cracker with a gun · 10-02-2012, 02:30 AM

Quote:

Originally Posted by SNAKESNIPER

Most paint these days bores out between .682 - .685 (I've even heard of rollouts through a .678). With that in mind, a .684 is really a paint-to-bore match, which is inherently inconsistent due to the size fluctuations with the paint itself. In the span of one hopperful of paint you might have balls in series where a few will be undersized, the next few could be oversized, a few could be oblong, etc etc etc. Now picture all of those escaping a single bore size that ALMOST matches all of them but not quite, and you can see how you would get inconsistent chrono readings.

This is why I believe that an underbore of .682 or less produces optimal consistency; because ALL size fluctuations will be larger than the bore. In effect, the control bore provides a "stop point" where the paint is squeezed and exits the barrel at a more uniform speed.

Someone else can probably explain this more eloquently than I just did, but the bottom line is to get an underbore barrel around .678-.682 and you'll see more consistent chrono readings. BTW when you're doing a blow test, a proper underbore won't allow you to blow paint through very easily, it will require a LOT of force.

agree'd.

most paint is coming out to a .684-.685ish... Ideal underbore is .003-.005; any more underbore might start to affect ball rotation, thus accuracy. So getting a barrel at a .682 would be ideal, .679 would be my next choice.

i usually do a basic blow through test, in which i dont see much gap in between the ball and the barrel (using different balls as they are not perfect) then going 1-2 sizes smaller. Example: i'd do a blow through test with .689, .687, or .684 and go down to a .682 or .679.

Pson · 10-02-2012, 06:38 AM

Well, I played around with it lastnight and I am pretty shocked to say the .682 had better shooting then the .684 and .679. I could could use the .679, but felt ball flight was better under a .682 setup. Thanks guys for explaining that in better detail.

Danny96211 · 10-02-2012, 03:46 PM

I currently own .682, .684, and .693 freak inserts. The only one i have used so far is the .684. Ive used it with two different paint brands numerous times. With one brand it was a perfect match while with the other it was a slight underbore. The only freak inserts you should need are .679, .682, .684, .687

cmdrsuds · 10-02-2012, 06:06 PM

overbore would be much more simple - buy a slightly larger insert as well and call it good.

SNAKESNIPER (Banned) · 10-02-2012, 06:32 PM

Quote:

Originally Posted by cmdrsuds

overbore would be much more simple - buy a slightly larger insert as well and call it good.

Overbores are very inefficient though, and not much more consistent than a bore match.

cmdrsuds · 10-02-2012, 07:15 PM

Quote:

Originally Posted by SNAKESNIPER

Overbores are very inefficient though, and not much more consistent than a bore match.

To each their own.. not gonna go into overbore vs underbore here, plenty of other threads on that - I overbore on my PM7 and underbore on my Karnivor and BOTH guns shoot great.

To the OP: If you want to buy an entire insert for underboring kit go for it, you won't be disappointed. If you want to overbore that's fine too. If you're having problems with accuracy look at the paint you're shooting (try some Neslon

) then gun settings and your reg(s). Underbore vs overbore would be your last step after all those things are optimal.

wowzerz · 10-03-2012, 01:45 AM

Quote:

Originally Posted by Pson

Well, I played around with it lastnight and I am pretty shocked to say the .682 had better shooting then the .684 and .679. I could could use the .679, but felt ball flight was better under a .682 setup. Thanks guys for explaining that in better detail.

Make sure you re-chrono each time you change bore sizes. As you decrease your bore your fps will rise.

Zippin35 · 10-03-2012, 09:06 AM

Quote:

Originally Posted by SNAKESNIPER

Overbores are very inefficient though, and not much more consistent than a bore match.

Has overboring been proven to decrease efficiency? I cant recall. I know that an underbore creates a seal behind the ball, causing all the air to be used as effectively as possible, yet it also creates drag. Overboring will allow some air to escape around the ball, but does not have to deal with the drag so they seem as though they would get similar efficiency numbers. If I recall correctly, the only method that was proved to be worse than the others was a direct bore match, over and under boreing will always have conflicting groups and with the imperfections of a paintball, they will probably never be settled. Pick one you feel comfortable with and stick with it.

For the best results, buy better paint!

Pson · 10-03-2012, 09:45 AM

Quote:

Originally Posted by wowzerz

Make sure you re-chrono each time you change bore sizes. As you decrease your bore your fps will rise.

Good to know and thank you. Have not chrono after cutting bore size to .682 from .684.

Pson · 10-03-2012, 09:47 AM

Quote:

Originally Posted by Zippin35

Has overboring been proven to decrease efficiency? I cant recall. I know that an underbore creates a seal behind the ball, causing all the air to be used as effectively as possible, yet it also creates drag. Overboring will allow some air to escape around the ball, but does not have to deal with the drag so they seem as though they would get similar efficiency numbers. If I recall correctly, the only method that was proved to be worse than the others was a direct bore match, over and under boreing will always have conflicting groups and with the imperfections of a paintball, they will probably never be settled. Pick one you feel comfortable with and stick with it.

For the best results, buy better paint!

Wish I could, but rules are field paint only and they only have Heat.

cmdrsuds · 10-04-2012, 06:16 PM

Quote:

Originally Posted by Pson

Wish I could, but rules are field paint only and they only have Heat.

Then over bore for sure IMO .. I have noticed underboring tends to be more picky to your paint. I noticed my Karnivor wasn't shooting as well as my PM7 one day when using field paint and was stumped at first.. then I thought I'd try switching the barrels and that solved the problem