Barrel Testing Archives - Porting Test

This test has been completed to determine the effects of porting on paintball barrels and answer questions such as: What happens if there is no porting at all? What happens if there is a very large amount of porting? And does it matter where on the barrel the porting is located? And finally, what kind of sound reduction can I expect? We also included our raw test data below.



The test was done with a TM-7 clamped down in front of a chronograph shooting 25 balls through each barrel, with every shot being recorded on the data sheet. The information on the data sheet can be found below for your reference. We used five barrel setups including:

• Un-ported
• Standard Ported4 rows porting 3" long)
• Double ported (8 rows of porting 3" long)
• SQB (4 rows of 3" porting and 4 rows of just over 6" porting, three times as much porting as standard)
• Middle porting (4 rows of 3 inch porting starting 6" into the barrel and ending 9" into the barrel)

Basically we observed for the most part what was expected. Un-ported barrels were the most efficient but the least consistent. However the consistency loss between the un-ported and ported versions of the same length barrels was small enough to be considered negligible. So the difference is not enough of a difference to have much real world impact on accuracy. The efficiency however is a bit more noticeable, at 20 FPS gained by going un-ported from the heaviest ported barrel we tested that shows about a 7% increase in efficiency. This means if you normally shoot 1000 shots off a tank with a heavily ported barrel, you can expect approximately 1070 shots with an un-ported barrel. You will also find the standard ported 12" barrel which is ported for efficiency (which means its ported enough to reduce volume somewhat, give a slight increase to consistency while trying not to hurt efficiency too much) was quite successful as the efficiency loss was extremely small compared to the un-ported barrel, however the volume was significantly reduced. Our double ported barrel (8 rows of porting) showed a bigger efficiency drop and no increase to consistency but yet another volume drop however not nearly as big as the ported vs. un ported drop. In fact, it had a lower consistency then the standard porting showing that additional porting does not always mean additional consistency.



The part of the test that some people may find interesting is the fifth setup we used which featured porting in the front middle of the barrel. The efficiency was basically the exact same as if porting was through the entire length of the barrel, as was the consistency. Now based on prior testing I know efficiency would have went down if that 3" at the front was not there but it seems ported or un-ported it does not make much of a difference once the middle section of the barrel is ported. As far as volume, the sound was basically the same as the double ported front. It’s no surprise that less porting gave an equal sound reduction since it’s not as close to the tip however with no real benefits over the double ported version I think it’s pretty clear there is no good reason to port the middle of a barrel.



Conclusion:

After the test it looks like for pure performance, standard efficiency porting will give best results. It’s also interesting to note that where the porting starts is as important as how much of it there is. For example the last 2 setups both had the porting start in the same place, and it was lighter porting at the beginning, the SQB has much more afterwards but it did not help much as both setups had the same efficiency and consistency, As far as volume goes we see a large drop from un ported to regular porting, and then another large drop going from regular porting to SQB and double porting.