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Posted: Mon Sep 03, 2007 7:24 am
by jackssmirkingrevenge
I think you can expect similar results with this, provided as always you use the minimum pilot volume, as long a barrel as you can make and a C:B ratio of at least 1:1
Posted: Mon Sep 03, 2007 7:31 am
by Mitchza89
I've been looking all night and had no luck. I feel like such an idiot for asking this but....I've never actually found out what it means. I'm talking about the C:B ratio. I'm thinking its got to do with the volume of air thats inside both the chamber and barrel, if your chamber is too small, the air will be gone by the time the projectile has left the barrel or the psi drop is too great to give any good results. Am I right?
Thanks alot for this mate.
Posted: Mon Sep 03, 2007 7:36 am
by jackssmirkingrevenge
You're on the right track, a C:B ratio is a Chamber volume:Barrel volume proportion, so the one I suggested (1:1) means that you should calculate that the volume of your chamber is at least the same as your barrel.
Posted: Mon Sep 03, 2007 7:47 am
by Mitchza89
Cheers. I reckon that the 40 off cm of 1/2in galvanised pipe should be more then enough for a meter off bb barrel
Posted: Mon Sep 03, 2007 7:51 am
by jackssmirkingrevenge
Mitchza89 wrote:Cheers. I reckon that the 40 off cm of 1/2in galvanised pipe should be more then enough for a meter off bb barrel
Assuming that's 1/2" I/D tubing then 25cm will suffice.
Posted: Mon Sep 03, 2007 12:54 pm
by noname
Jrrdw, neither 9/32" or 5/16" fits .177 BBs well. The best fit for 6mm airsoft BBs would be 8mm OD copper (UK) or 9/32" brakeline.
Posted: Mon Sep 03, 2007 1:45 pm
by Spuddin
i can tell u that 5/16 works for 6mm bb's but they do not fit very tight, u loose alot of air blowing around the bb but if its all u can find it will work.
Posted: Tue Sep 04, 2007 12:00 am
by jackssmirkingrevenge
Mitchza89 wrote:Wow. Thats really well made mate. Would have taken a while not to mention alot of planning to build.
I actually made it in a couple of days, the construction is basically identical to my preloaded pneumatic cartridge prototype, I detailed the process
here.
Posted: Tue Sep 04, 2007 4:07 pm
by A a r o n
While we're on the subject of barrels, whats the best diameter brakeline for .177 cal. bbs?
Posted: Tue Sep 04, 2007 7:31 pm
by Mitchza89
5/16th is a bit too big for .177 bb's as far as I know so 9/32 would be your best bet.
Posted: Tue Sep 04, 2007 7:33 pm
by noname
1/4" brakeline is the best brakeline for .177 BBs, and 9/32" brakeline is the best for 6mm airsoft BBs.
Posted: Tue Sep 04, 2007 7:44 pm
by Mitchza89
Ohh breakline? Sorry I missread.. Yeah best not to listen to me for any answers anymore haha
