Best barrel diameter 6.08mm Vs 6.04mm and below?

[Nadrian]

Been looking at barrels for a while now and wondering what you guys think? I was told and therefore believed that around 6.03 and 6.02 was the best possible barrel for accuracy and range but.. then i was shown this http://www.x-fire.org/etop/08.html the PDI 6.08mm barrel and apparently is far more accurate and has an increased range over 6.04mm and below barrels, So i'm just basically wanting you guys to discuss/inform me so i can make a judgement, Cheers.
Also anyone here got the PDI 6.08mm barrel? and any records of performance (i have found next to no information on the web)

[Nadrian]

Re: Best barrel diameter 6.08mm Vs 6.04mm and below?

Anyone know anything about this? still need to know

[Boo-Sabum Ben]

Re: Best barrel diameter 6.08mm Vs 6.04mm and below?

Someone (Not the on the forum I dont think) did a test once, with a whole bunch of barrels, and the Prometheus 6.05 came out on top.

[Lt. Macka]

Re: Best barrel diameter 6.08mm Vs 6.04mm and below?

Well I know that the 6.01mm barrels don't work so well.

6.03/04 seem to work well enough.

I've not seen these 6.08mm barrels in use so can't comment. Buy one and try it?

[B.E.N.]

Re: Best barrel diameter 6.08mm Vs 6.04mm and below?

I had a PDF of a study a while back, it was probably on my old machine, but it was commissioned by Madbull and performed by a German company.

Basically, they scanned the cross section of sample barrels down the length with some kind of electro-spectral x-ray thinger, that allowed them to measure the shape and consistency of the bore down the barrels length.

You see, the tightness of bore, and the consistency (roundness) of the hole are equally important. Having a 6.01mm bore is useless, if the hole goes from oval to round and back again several times down the length of the barrel. Obviously, the spin on the results was that Madbull barrels offer "the best" balance of precision, consistency and cost, but it wasn't possible for them to hide the fact that Systema's 6.04 barrel was very accurately bored, perfectly round and at a great price, it just wasn't as tight.

The Prometheius barrel was also very accurate, and VERY round down the length, it was just very expensive too. Interesting, the CA barrel was worst, with an massively irregular bore and a variation of -6mm to about 6.08mm if my memory serves correctly.

Another downside I've found is that a very tight bore barrel, no matter how much you spend, is always going to cause problems if you try and blow cheap, irregular BBs down it. It's for that reason many techies will recommend a more tolerant bore for general skirmishing, since you can pump out average quality BBs without too much of an issue.

(for the record, I use Systema and Madbull barrels in my AEGs and get great results with both...)

[Nadrian]

Re: Best barrel diameter 6.08mm Vs 6.04mm and below?

Thanks B.E.N Was an interesting read and very informative still would like to know about these 6.08mm barrels but nobody seems to have heard/used one of them but thanks never the less and Lt Macka as much as i would love to but 70 pounds+ shipping isn't something i'd try on a whim to check the product, but thanks for the input .Does anyone know someone who uses them? Cheers

[B.E.N.]

Re: Best barrel diameter 6.08mm Vs 6.04mm and below?

Since PDI have a good reputation in the field of making barrels, it'll be worth a punt if you really need a new barrel.

What BBs are you likely to use BTW?

[Nadrian]

Re: Best barrel diameter 6.08mm Vs 6.04mm and below?

Excel .25's-.28s depending on how good the new hop up setup i'm looking at deals with them (Neo Strike Chamber w/Firefly Bucking and Nub or Systema bucking and SCS H nub) and my stock G&P Barrel hasn't been too bad so far just wish there was more information available.

[Caveira]

Re: Best barrel diameter 6.08mm Vs 6.04mm and below?

I may be well off the mark here and if I am I'm quite happy to be corrected, but...

As far as I can see, there's two issues. Keeping the BB rolling in a consistent manner while in the barrel and keeping a predictable airseal in the too.

I'm under the impression (from what I've read here and elsewhere) that the BB tends to ride the top of the barrel due to the hop. If that is in fact the case, surely the diameter of the barrel becomes irrelevant as only one part of it is inluencing the path of travel. You could go further and suggest that a larger diameter would give a better margin of error as any blemishes in the barrel would be proportionatly smaller.

On the other hand, a smaller barrel allows less air to escape around the BB making the airflow more predicatable. The twist barrels seem to use the air escape principle to provide a cushion for the BB to ride in, but are limited to mid range power levels as the turbulence in the barrel disturbs the BB as powers increase. Too large a bore and the air will flow under (?) the BB, then move upwards to resume it's normal path of least resistance, leading to a disturbed BB path and quite possibly a lower speed BB as Bernouli's principle would state that faster air moving under the BB will drag it downwards to to lower pressure (the opposite of the hop effect).

It's no good having a 100% accurate barrel, regardless of diameter) if the BBs aren't moulded and polished perfectly too. The variations in BB manufacture are far greater than those in barrel machining. I'd suggest that we all (myself included) are perhaps a bit too quick to rip out the old barrel and hop when we see less than perfect accuracy. A black python barrel (which I tend to use in all my guns) has a great balance of tollerences and price, but the accuracy of the finishing is FAR better than that of all but the most expensive BBs.

Perhaps an averagely priced barrel, matched with a consistent hop unit would be the best option for most of us. That way we could afford to bung much better made pieces of circular plastic down it at each other.