What Barrel Length goes with what bb weight in an AEG? - Page 3 - Airsoft Sniper Forum
       

Go Back   Airsoft Sniper Forum > The Rifles > Longrange AEGs
Longrange AEGs Converted AEGs

Like Tree44Likes
Reply
 
LinkBack Thread Tools Display Modes
Old 07-27-2019, 03:45 PM   #31
Jr. Sniper
 
ArcAngel's Avatar
 
Join Date: Jun 2014
Posts: 447
Short answer,
18" barrel with .36g bbs and a m120 and no port cylinder and a full metal rack plastic piston and plastic piston head for a standard field legal rifle seems to be a perfect sweet spot for accuracy and power in my experience.

With that data I've lenghtened and shortened barrels for different fps setup and have had a lot of success with my recent builds.

The math at this point to me is meh to me. Its like one of those vertical line charts in my head, you move one variable up another goes down, then I move a third to compensate. Anyone else get what im saying? or am i nuts?
  Reply With Quote
Remove Ads
Old 07-27-2019, 04:51 PM   #32
1tonne   1tonne is offline
Veteran Sniper
 
1tonne's Avatar
 
Join Date: Jun 2012
Location: New Zealand
Posts: 4,902
Yip. Shorten the barrel and move the port forward stuff like that.
Or, put in a bigger spring and shorten the barrel.
One variable goes up and the other goes down.


You should check the energy rating of the 0.36gm bb with the 18" (450mm) barrel and then put in a 380mm barrel. It should make the smallest gain. Probably only about 0.05 joules though. So it is meh.
kazuchan likes this.
__________________
There is no advantage with R-hop or Maple Leaf
https://www.airsoftsniperforum.com/3...tml#post425335

Advanced VSR Sniper Building Guide
https://www.airsoftsniperforum.com/s...ead.php?t=6075
Advanced L96 Sniper Upgrade Guide
https://www.airsoftsniperforum.com/s...ead.php?t=6465
  Reply With Quote
Old 10-22-2019, 10:16 AM   #33
Young Gun
 
FlatDarkEarth's Avatar
 
Join Date: Sep 2016
Location: Austin, TX
Posts: 13
First off, huge thanks for this! Couple of questions on how this works - or let me think out loud:

-We're juggling a lot of variables here. Which factor is most important?

Energy
BB weight
Amount of Hop
Volume Ratio
Barrel Length

My gut says BB Weight, with Energy being close second, because the way the projectile behaves in the air is what we're really after. However, we tend to work with or think of guns in terms of energy output, so sometimes that becomes a primary consideration. Amount of Hop applied depends on BB weight, so there's just sort of a "right answer" for a given BB, but it gets colored by the other factors and type of hopup system, etc. Barrel Length and Voluming are just about efficient ways of achieving the above effects. And then those have follow-on effects in gearbox efficiency, sound levels, etc.

-So, if I start with the BB and work down the list from there: I want to shoot .32/.33g BBs. How little gun can I get away with?

-Now, let's impose a 1.5j limit as our primary consideration (because rules/playstyle goals). Is there a maximum useful BB weight for highly efficient bucking styles like a Crazy Jet/Hybrid, or a really well set-up RHop/flat hop in a 1.5j gun? Or, is there a practical FPS/energy floor for those styles of bucking?

-If so, what would be your highest expectation for the range potential of a 1.5J gun be?
__________________
Quote:
Originally Posted by Dimitri MdP View Post
Really, all the theory in the world can't take the sniping out of sniping.

Last edited by FlatDarkEarth; 10-22-2019 at 04:59 PM.
  Reply With Quote
Sponsored Links
Advertisement
 
Old 10-22-2019, 01:27 PM   #34
1tonne   1tonne is offline
Veteran Sniper
 
1tonne's Avatar
 
Join Date: Jun 2012
Location: New Zealand
Posts: 4,902
1.5 joules, I would use a 0.36gm bb and a 6.01mm barrel that is about 480mm will be somewhere around the most efficient ratio with a full cylinder. You could use a shorter barrel and also port the cylinder if need be.
There are minor variables that can change the ratios mentioned but overall if you have a 100% air seal, the barrel lengths should be about right. I guess the biggest variable is inner barrel diameter.
__________________
There is no advantage with R-hop or Maple Leaf
https://www.airsoftsniperforum.com/3...tml#post425335

Advanced VSR Sniper Building Guide
https://www.airsoftsniperforum.com/s...ead.php?t=6075
Advanced L96 Sniper Upgrade Guide
https://www.airsoftsniperforum.com/s...ead.php?t=6465
  Reply With Quote
Old 10-22-2019, 04:05 PM   #35
Young Gun
 
FlatDarkEarth's Avatar
 
Join Date: Sep 2016
Location: Austin, TX
Posts: 13
I'm surprised you recommend as high as a .36g. Seems like muzzle velocity might be a bit low, so I'm interested in why you find that weight works.

The first post mentions matching barrel length to ported cylinder volumes, but I assume we could do the opposite as well? In order to keep overall rifle length down and have a handier gun, I could give up some compression length? Then, maybe bump up a spring to keep it in the 1.5j ballpark, and hopefully since that energy level is all I'm trying to accomplish it won't be too extreme a gearbox setup - not too far into diminishing returns.

Edit: Oh, derp. Y'all just covered this a few posts before.

Edit 2: This tells me that the volume ratio is more important than the actual barrel length, in terms of the list of priorities in my post above.

My interest is more along the lines of maximizing an average size gun (m4 or similar) at average energies than in chasing the extremes of what's possible in a DMR. More of a sleeper build, I guess.
__________________
Quote:
Originally Posted by Dimitri MdP View Post
Really, all the theory in the world can't take the sniping out of sniping.

Last edited by FlatDarkEarth; 10-22-2019 at 04:57 PM.
  Reply With Quote
Old 10-22-2019, 10:02 PM   #36
1tonne   1tonne is offline
Veteran Sniper
 
1tonne's Avatar
 
Join Date: Jun 2012
Location: New Zealand
Posts: 4,902
I match all of my builds. My main M4 has a barrel length of about 190mm and with the port in the correct position, it works great. At 1.13j I use 0.28gm
__________________
There is no advantage with R-hop or Maple Leaf
https://www.airsoftsniperforum.com/3...tml#post425335

Advanced VSR Sniper Building Guide
https://www.airsoftsniperforum.com/s...ead.php?t=6075
Advanced L96 Sniper Upgrade Guide
https://www.airsoftsniperforum.com/s...ead.php?t=6465
  Reply With Quote
Old 11-09-2019, 09:14 AM   #37
S/UMP   S/UMP is offline
Young Gun
 
Join Date: Nov 2019
Location: Uk
Posts: 21
Just worked out ratios using this thread.


Current spec AEG, max legal limit is 1.3j or 374fps @.20
Most game sites run a hard 350fps @.20 so no worrys about straying into a section 5 firearms offence.
So V3 gearbox, full cylinder 70x23.5mm, 247mm 6.03 barrel = a wopping 4.30 - 1
3/4 cylinder 46x23.5 = a nicer 2.83 - 1
1/2 cylinder 35x23.5 = 2.15 - 1



Haven't accounted for hop/nozzle volume or piston/head in cylinder. In short the very long awaited cylinder swap from full to 3/4 should make things quieter and reduce turbulance on BB's as they exit the barrel. :)
  Reply With Quote
Old 09-14-2020, 01:32 PM   #38
Young Gun
 
tigerstr's Avatar
 
Join Date: Dec 2016
Location: Athens, Greece
Posts: 12
Ι must say that I found this article to be a great asset for my V2.5 DMR built. I would also like to add that a heavy piston head seems to play a big part in getting results ( best performance with heavy bbs). My built uses a 6.04 16 inch barrel and gives the best output (with a 130 spring), with 0.40 bbs. Exaclty as pre-determined here and planned in the built.

Many thanks to the OP ( @1tonne) and a... question for another of my builds, this time a "light DMR" configuration with a full V2 cylinder, type 0, a 16 inch barrel (407 mm) and a 120 spring, since I am pondering between a 6.01 Edgi and a 6.03 Promi barrel.

OP wrote:

NOTE: I have also noticed that when using a 6.01mm barrel, the barrel length can be increased by up to about 10% depending on the bb weight used. The lighter the bb, the longer you can go. This would be due to less air wastage.

Sounds quite reasonable but is a bit vague. What would be the "percentage length gain" for the barrel by using a 6.01 and 0.32 bbs and an 120 spring? Or maybe it would perform best with 0.36 bbs?
__________________
Improvise, adapt, overcome

Last edited by tigerstr; 09-14-2020 at 01:40 PM. Reason: clarity
  Reply With Quote
Old 09-14-2020, 02:33 PM   #39
1tonne   1tonne is offline
Veteran Sniper
 
1tonne's Avatar
 
Join Date: Jun 2012
Location: New Zealand
Posts: 4,902
For 0.32gm in a 6.01mm barrel = Anywhere between 400-440mm. It can be a little bit of a guessing game and so I would most likely go for 440mm.
SiliconeSword likes this.
__________________
There is no advantage with R-hop or Maple Leaf
https://www.airsoftsniperforum.com/3...tml#post425335

Advanced VSR Sniper Building Guide
https://www.airsoftsniperforum.com/s...ead.php?t=6075
Advanced L96 Sniper Upgrade Guide
https://www.airsoftsniperforum.com/s...ead.php?t=6465
  Reply With Quote
Old 09-14-2020, 03:44 PM   #40
Young Gun
 
tigerstr's Avatar
 
Join Date: Dec 2016
Location: Athens, Greece
Posts: 12
Quote:
Originally Posted by 1tonne View Post
For 0.32gm in a 6.01mm barrel = Anywhere between 400-440mm. It can be a little bit of a guessing game and so I would most likely go for 440mm.
Thanks for the prompt reply @1tonne , much appreciated! Will get back with the results of the upcoming built.
__________________
Improvise, adapt, overcome
  Reply With Quote
Reply


Search tags for this page
aeg barrel lenght bb wieght
,
aeg cylinder port barrel length list
,
airsoft barrel length guide
,
airsoft dsg range
,
airsoft spring size calculator
,
bbs best for 155mm aeg barrel with 0 cylinder
,
dsg
,

news

,
v3 best barrel length airsoft
,
v3 gearbox barrel length
,
what aeg spring for my barrel length
,
what kind of cylinder to use with a 368mm barrel
Click on a term to search for related topics.

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On


Similar Threads
Thread Thread Starter Forum Replies Last Post
Cylinder:barrel ratios explained Reliku General Sniper Talk 199 06-25-2020 09:16 AM
Advanced VSR Sniper Building Guide 1tonne VSR Rifles 493 04-12-2020 08:43 PM
Advanced L96 Sniper Upgrade Guide 1tonne Type96 180 10-22-2019 01:52 PM
Why airsoft guns are not that accurate (long grab some coffee) paulmohr General Sniper Talk 61 05-07-2017 03:39 PM
How to get maximum Joule Creep from an AEG 1tonne Longrange AEGs 89 02-06-2017 01:24 PM



All times are GMT -5. The time now is 11:15 AM.


Powered by vBulletin® Version 3.8.8
Copyright ©2000 - 2020, vBulletin Solutions, Inc.
SEO by vBSEO ©2011, Crawlability, Inc.
vBulletin Security provided by vBSecurity v2.2.2 (Pro) - vBulletin Mods & Addons Copyright © 2020 DragonByte Technologies Ltd.