Barrel size

[sniperslucky]

Hi All,

What impact does the inner diameter have on FPS 6.01-6.03, i have heard that the bigger the bore the more FPS reached ifso how would the FPS react to a 7.10 inner bore????

 

[Sitting Duck]

7.10 bore ???

that would be like going last at some Vegas brothel at closing time

tighter bores generally increase fps a little - 10% ish

but tbh some stock barrels are quite good vs a poor tbb that often this may not always be the case

wider bores you generally will lose a bit of fps around the bb

 

[Hef Legend]

Duck is right. From experience going from a stock 6.08 barrel down to a 6.02/3 usually results in about 10% depending on length too.

Widebore barrels reduces fps as the pressure behind the BB is less as the air has more area to flow past.

Depending on set up, one may or may not provide you with other benefits such as range/accuracy.

Also worth considering quality of the bore, a shite 6.01 will perform worse than a polished 6.08

 

[sniperslucky]

7.10 bore ???

that would be like going last at some Vegas brothel at closing time

tighter bores generally increase fps a little - 10% ish

but tbh some stock barrels are quite good vs a poor tbb that often this may not always be the case

wider bores you generally will lose a bit of fps around the bb

call me blind , but i could not see any reference to barrel sizes in those two links ???????????

 

[sniperslucky]

I was searching the internet for suppliers of brass tubing, as most are priced better as they post them for hobby making rather than paying over the odds for a brass barrel from a retailer. But i couldn't get a tight bore under 7.10mm!! .As yet again the company i brought the gun from lied about the FPS.

Also barrel length was 550mm due to adding a fake flash hider.

 

[proffrink]

Surface finish matters more on barrels than bore diameter. Please search for this though - there must be 100 threads on it on here alone. Barrels are one of the most talked about things in airsoft, so do the legwork.

Go PDI or EdGI if you can afford it. If not then LayLax/Prometheus.

I mean you could buy your own brass, but you'd need to polish it very well, you'd need to crown it and you'll need to cut the window in it.; after all that it's just not worth it. Unless you have access to a CNC mill the amount of man-hours you'd have to put into it will easily exceed how much you'd have spent on it anyway.

 

[Sitting Duck]

the whole process takes loads of lapping to get the surface as close to true smooth perfection as possible

see HS5 spending yonks with various grades of paste to get improved results

the crowning is more than just jamming in a dremmel polishing stone in the end

And he knows a "little" bit to say the least...

(I know absolutely f*ck all by comparison)

barrels are usually about 6.05 stock

some stock barrels are better than others but still probably miles better than hacking up a bit of pipe and making a DIY barrel

TBB are about 6.03, 6.02 or 6.01 - though too tight on longer barrels will very likely jam more, these tbb will in most cases increase fps a little

Wide Bore are more used for hpa setups I think as the drop can be compensated easily

if barrel is ok - just clean it and concentrate on hop/bucking

if you wish to alter the barrel length a little maybe try a £20 one if on a real tight budget like zci/tornado

(avoid madbull is mine and many others opinion - save up for the higher quality barrels)

but often - people mess with barrels thinking it will change so much when in fact it don't or even make matters a little worse

and the average DIY one will very likely to be quite $hit on par with hacked bits of pipe found in JBBG guns

Think you could turn out other custom/bespoke bits n bobs that might function ok - but barrels ergh no I don't think so

3d print bits, make flash hider from delrin or stuff - loads of little bits you could knock up ok but precision barrels - nahhhhhh

 

[ImTriggerHappy]

Is this a real thread or a wind up?

 

[jcheeseright]

give it a few weeks and there'll be a 'help please' thread:

"fitted my new barrel that I made out of some brass pipe and my accuracy and range have gone down the toilet, I think it's my tappet plate... could anyone advise a good material I can carve a new one from?"

On the subject of barrels, in Japan Tokyo Marui OEM barrels sell second hand for more than prometheus/PDI go for new. Food for thought.

 

[ImTriggerHappy]

On the subject of barrels, in Japan Tokyo Marui OEM barrels sell second hand for more than prometheus/PDI go for new. Food for thought.

Nope that just another thing that proves Japanese consumerism is weird (45yr olds collecting barbies and trading cards).TM barrels are absolutely fine but nowhere near the same league as PDI or prommy. Japanese are the worlds worst at buying the same brand even though there is better on the market look at how well Nintendo consoles still sell.

 

[PT247]

for my 2p worth... on my PDW Krytac the stock inner barrel is as good as a Prommy barrel of slightly longer length which suggests it is better quality as is shorter so in theory less fps (as it goes; on the chrono made no difference)

 

[Sacarathe]

for my 2p worth... on my PDW Krytac the stock inner barrel is as good as a Prommy barrel of slightly longer length which suggests it is better quality as is shorter so in theory less fps (as it goes; on the chrono made no difference)

Unless the system only had enough air volume for the default barrel, undervoluming can cause the BBs to decelerate in the barrel.

 

[Sitting Duck]

Oh jeez lay off the science stuff a sec - my brain hurts....

just opened 3 cans of worms in 3 other forums in under 36hrs

I've come back here for some peace & chill time

 

[Samurai]

is shorter so in theory less fps

Only if the cylinder is not matched to the barrel.

 

[Sitting Duck]

just wondering was it too much science or

a tarantula on her right breast that made her pass out ???

 

[PT247]

Aye could be down to volume but it works fine with both SPR and PDW length barrels which suggests otherwise.

 

[Sacarathe]

just wondering was it too much science or

a tarantula on her right breast that made her pass out ???

What! Some of the first physics children learn is through a straw!

 

[Jambo88]

That's a little personal.

 

[Sacarathe]

That's a little personal.

What is?

 

[Jambo88]

What is?

Size of my barrel