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bvdave
03-26-2010, 12:33 PM
Im posting up a few of the barrel tests ive done over the past year or so for anyone who is interested, Ive been doing quite a large number of tests with various factors over the past year and ive started making some of the results public to help explain why I made my kits the way i did, I would rather show that I made them because of where the data led me rather then just telling my customers (or at least those whom care enough to research for themselves) that it works simply because I say it does. I have been prototyping barrels like crazy for many of these, if anyone has any comments or ideas please post them up, Im always looking to learn more so insight or even ideas for new tests is highly appreciated as is criticism. many of these I have already made public so I figured there was no need to stash em away in the insider forums. most of the tests I run I will run again several times later to double check the results against itself and ensure my data did not come from chance also, but I generally wont post the same test more then once.

First a quick bit of info about my barrel system. First off, my barrels are designed for scenario players, woodballers etc etc, not for speedball, they will work just fine for speedball and I think in some case perform better due to the types of valves traditionally used in speedball markers over woods ball markers (explain that later in one of the tests) but they will probably look odd on most speedball markers, they are a 2+ piece barrel system, consisting of the barrel, a barrel tip, and in many cases a barrel extension. Unlike most barrel kits I don’t use backs and fronts, no front is required if you want to keep the barrel shorter. Also the barrels are male threaded on both sides, (where most are female threaded on the front) this gives a longer control bore and it allows more versatility which comes in handy when testing. all tips are female threaded in the back and all extensions are female threaded in the back and male in the front. which means I can take a 9" barrel, put a 5" extension on the front, then another 3" extension on the front and have a 17" barrel, and then go again and put a barrel tip on the front of it all. my extensions also have various porting methods which also comes in handy with testing because its so modular I can make many different patterns for testing without needing entirely new barrels.

bvdave
03-26-2010, 12:34 PM
First is a test that was done more recently, this one has sparked quite the controversy also, basically theres 5 barrels that are 9" long each with no porting in various bore sizes, many of my tests have shown better efficency with longer control bores then what most of the industry has been using (many 5-6 inches and many as few as 2 inches or so) hence the long length of the barrels used. The first colums are the barrels with no ported extensions (fronts) next with a 3" extension and followed by a 5" extension, used were marbs and DXS Silver (all unnamed were marbs agaian)

basically what we saw is every time the bore size was increased, the spread got smaller, this test was repeated several times with the same results. once we even used a paint that was so small it measured .675 and it still shot better in the .693 then it did in the .681 (I just made a few more barrels in .696 and .700 to see how far it can go before the bore gets too large and the ball starts loosing accuracy) that said efficency is allready pretty low when overboring that much.

that said, tests with other barrel kits almost never see this, so the working theroy right now is the Bernoulli's Principle is causing the effect and needs more then the 6" which is usually given by most barrel kits to give this effect and increase in accuracy, Ive also put together some 11" control bores to see what happens with a bit more length, but that test is not yet completed.

Tests were done with 25 shots for each set, test was done at 75 feet with a BT TM-7 (mini engine) also marker was rechronoed between barrels to ensure a consistant velocity. marker was bench clamped down and not held by human hands to remove error and ensure consistancy

http://flasc.com/images/tests/controlboretesting.jpg

bvdave
03-26-2010, 12:36 PM
heres a test I did last week to test control bore lengths. I has some prototypes made up with the following backs to see what the optimal length for control bores are. total lengths I tried to keep as close as possible with the extensions (fronts) I had, I am having new ones made up next month so I can get exact total lengths and not have these small variations to throw off my tests

2.5"
5"
7"
9"
11"


each length I have 3 bore sizes, .682 .688 and .693, I did one test with fronts that had porting start at 9" and one with no porting whatsoever.

With Porting
http://www.flasc.com/images/tests/controlboremarch15th.jpg


Without Porting
http://www.flasc.com/images/tests/unported%20control%20bore%20length%20test%20March% 2025th%20201%600.jpg

I also tested on 3 different markers with different valve styles to see if the optimal length changes between marker styles,

For CVX I used a BT-4, for Poppet I used a TM-7 and for Spool I used a SP1. all barrels were .689 and I used paint that measured between .688 and .689 to get as close to a bore "match" as possible
Basically i found for CVX the optimal length to be between 6 and 9 inches (probubly best at about 7.5 or so). the Poppet to be right at about 9" and the spool to be between 9 and 12 inches (probubly optimal at about 10.5 or so). now that doesnt mean every spool valve marker will be in that range.. I only tested one. but I still found the results to be quite interesting and overall in average the ideal length for a control bore is found in my testing to be around 9" long.
http://www.flasc.com/images/tests/Control%20Bore%20vs%20valves%20March%202nd%202010% 20TEST%202.jpg

bvdave
03-30-2010, 03:00 PM
More to come soon :)

Nick
03-31-2010, 03:17 PM
Thanks for this, I have a .693 CP 2 Piece, I should probably get a smaller bore back lol..

bvdave
03-31-2010, 04:22 PM
i played with a .700 bore prototype last week, loved it shot like a charm, innefficent as anything ive ever seen, but shot wonderfully :)

Also in the first post where you see bore sizes, Vectors were used to measure so smaller numbers are better (smaller spread)