Barrel length effects on accuracy - Breakdown and recommendations

[ParHunter]

Thanks for the link @Pseudotectonic very helpful! I understand that a stronger spring would compress the air quicker and thus provide more acceleration. I was just wondering whether the spring comes into the equation for determining the optimal barrel length but it seems not.

[Sewdhull]

You will note that there is no optimum barrel length for a cylinder volume, there is a range of ratios and this is because of the other variables, air pressure loss and starting pressure, BB mass, hop setting, barrel bore and general quality. Also what your goal is for the system.

 

Ratios quoted like 2 to 1 etc are to allow there still to be useful pressure in the system so the BB is still accelerating in the barrel, still supported by an air cushion. In this case and any case where there is more than 1 to 1 ratio(without losses), a stronger spring will allow more energy to be imparted to the BB in the same length of barrel or keeping the same spring allow a longer barrel to absorb more energy in a longer time or combination of the 2.

 

In a zero loss system with 1 to 1 ratio there would be no purpose in a longer barrel, regardless of spring strength because altho average pressure would be higher it would still be atmospheric when the bb left the barrel.

 

I too enjoy flecktarn kit.

 

 

[ParHunter]

Given the calculator @Pseudotectonic linked to I’ve established that the ratio for my TAC41 LS is 4.32 with the 330mm barrel (the volume of the cylinder is quoted as 41cc). That sounds way too high. Even with a 440mm barrel it is still a ratio of 3.25.

 

I have yet to play with the TAC41 or shoot it at any distance further than 10m so I have no idea how she actually behaves on the field so I won’t go ahead and order a longer inner barrel just yet (which Airsoft retailer is best for parts?) but I would like to plan ahead.

 

Coming back to my idea of printing a ‘silencer’ with a build in barrel extension (probably not at 6.05 but a bit wider). I didn’t study fluid dynamics but I could imagine that it would be very easy to create turbulences and make things considerably worse. Am I right with my guess or could a little gap between the inner barrel and the barrel extension actually ‘release’ some of the excess pressure without creating turbulences around the BB?

 

Update: 

ChatGPT shot down my idea saying that it would indeed create turbulences. So would probably go down the route of a longer inner barrel which would be concealed by a suppressor. 

Edited October 13 by ParHunter

[Adolf Hamster]

3 hours ago, ParHunter said:

Given the calculator @Pseudotectonic linked to I’ve established that the ratio for my TAC41 LS is 4.32 with the 330mm barrel (the volume of the cylinder is quoted as 41cc). That sounds way too high. Even with a 440mm barrel it is still a ratio of 3.25.

 

I have yet to play with the TAC41 or shoot it at any distance further than 10m so I have no idea how she actually behaves on the field so I won’t go ahead and order a longer inner barrel just yet (which Airsoft retailer is best for parts?) but I would like to plan ahead.

 

Coming back to my idea of printing a ‘silencer’ with a build in barrel extension (probably not at 6.05 but a bit wider). I didn’t study fluid dynamics but I could imagine that it would be very easy to create turbulences and make things considerably worse. Am I right with my guess or could a little gap between the inner barrel and the barrel extension actually ‘release’ some of the excess pressure without creating turbulences around the BB?

 

Update: 

ChatGPT shot down my idea saying that it would indeed create turbulences. So would probably go down the route of a longer inner barrel which would be concealed by a suppressor. 

 

if you mean the suppressor causing turbulence, i can't say i ever noted an accuracy penalty from running one.

 

that is, as long as you skip the fart flap, that'll make a barn door an optimistic target from inside the barn.....

[ParHunter]

1 hour ago, Adolf Hamster said:

 

if you mean the suppressor causing turbulence, i can't say i ever noted an accuracy penalty from running one.

 

that is, as long as you skip the fart flap, that'll make a barn door an optimistic target from inside the barn.....

It wasn’t about the suppressor but printing an inner barrel extension inside the suppressor when you can’t achieve an air seal between the inner barrel and the extension.

[TrooperX]

I had one of the original JG G36Cs back in 2000andsomething.  What’s that, a 250mm inner barrel?  The range and accuracy was insane. There just seemed to be a sweet spot with the overall set up of a lot of those back then.

[Adolf Hamster]

8 hours ago, ParHunter said:

It wasn’t about the suppressor but printing an inner barrel extension inside the suppressor when you can’t achieve an air seal between the inner barrel and the extension.

 

Ahh, yes that won't really be much benefit, getting the join to line up well enough to not mess up the accuracy isn't really practical.

 

You'd be better off with no barrel extension and just an empty can

[Cannonfodder]

 I've had some pistols with barrel extensions and I never used them as they ruined accuracy.

I don't know if them being GBB rather than AEGs makes any difference but I guess not

[EDcase]

Given how sensitive accuracy is on inner barrel quality, its almost impossible for two barrels to screw together perfectly enough.

[Sewdhull]

3 hours ago, EDcase said:

Given how sensitive accuracy is on inner barrel quality, its almost impossible for two barrels to screw together perfectly enough.

I d agree here, alignment of the barrel would be really tricky.