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tightbore question

Posted: Thu Jan 21, 2010 2:39 am
by grock
everyone know not to put used/low quality bbs through a tightbore in an AEG. everyone says it will "mess up the barrel" on the other hand, ive put many thousands of used/low quality bbs through a 6.25mm barrel with pretty much no problems. i happened to get my hands on a 6.03mm barrel that im thinking of using in a bbmg. how bad will used/bad bbs mess up that tightbore? or is it not an issue when shooting more than 50 per second?

thanks

Posted: Thu Jan 21, 2010 3:15 am
by jackssmirkingrevenge
Path of least resistance, what's going to wear out - brass or plastic?

Posted: Thu Jan 21, 2010 3:32 am
by Davidvaini
tightbore barrel is better for accuracy and efficiency. 6.25 will have a lot more blowby which means more air escaping around the BB. You will have increased power.

the real reason not to use bad quality BBs in a tightbore is not because they will mess up the barrel, its because of size... bad quality BBs sometimes have seams, or are larger than the diameter of the tightbore barrel.. if this is the case, you get a jam. A jam in a normal AEG means you just cant fire.. but a jam in a BBMG could mean you are filling your BB chamber up to whatever psi you are running. This can be an issue sometimes if you are using DWV or other ghetto materials to build your BBMG as they arnt recommended for anything with pressures, certainly not the typical operating pressures of BBMGs(60- 140 psi).

Posted: Thu Jan 21, 2010 9:35 am
by jimmy101
Davidvaini wrote:... a jam in a BBMG could mean you are filling your BB chamber up to whatever psi you are running. This can be an issue sometimes if you are using DWV or other ghetto materials to build your BBMG as they arnt recommended for anything with pressures, certainly not the typical operating pressures of BBMGs(60- 140 psi).
A BBMG really should be built to handle whatever the max pressure is that the compressor will put out. Since most pressure rated PVC is good to at least 180 PSIG or so it really isn't a big problem. (Cleanouts may be a problem since they aren't generally pressure rated.)

Posted: Thu Jan 21, 2010 5:22 pm
by ramses
Another issue to consider is not "wearing out" the barrel, but deforming it slightly. Depending on the mass of the BB's(that determines the "wall thickness" of the sphere) they can be hard to crush. It is easier to make the ~1mm wall tubing slightly not round than it is to deform the BB. Since the circumference is pretty much constant, this means that in a different dimension, the tube will be a smaller diameter, that is to say it may become slightly elliptical. The next BB may correct this, but then you get issues with fatigue in the barrel.

Just my opinion, and IIRC walmart BB's can be more expensive than good ones in bulk.

Posted: Fri Jan 22, 2010 2:47 pm
by grock
should jamming be a problem if i have the bbmg built to handle my operating pressure? will it result in catastrophic failure or just a higherpowered shot after a short pause?

Posted: Fri Jan 22, 2010 3:03 pm
by jackssmirkingrevenge
grock wrote:should jamming be a problem if i have the bbmg built to handle my operating pressure?
If the above is true, then the
will it result in catastrophic failure
shouldn't happen.
or just a higherpowered shot after a short pause?
Depends on the severity of the jam, the shot might not happen at all and you make have to tap it out manually.

The simple solution is quality BBs ;)

Posted: Sat Jan 23, 2010 12:42 am
by kozak6
jackssmirkingrevenge wrote:Path of least resistance, what's going to wear out - brass or plastic?
If he's firing dirty dusty gritty used bb's through a tight barrel, there could very well be some scratching and wear.

It's a shame to unnecessarily damage a barrel, but if the barrel is strafer only, I wonder if it would have much of an effect on the, um, effectiveness.

Posted: Sat Jan 23, 2010 11:00 am
by grock
jackssmirkingrevenge wrote: The simple solution is quality BBs ;)

well, that being siad, the bbs i use are about $12 for 5000. anyone know where i can get good bbs for cheaper than that?

Posted: Sun Jan 24, 2010 1:11 pm
by ramses
grock wrote:
jackssmirkingrevenge wrote: The simple solution is quality BBs ;)

well, that being siad, the bbs i use are about $12 for 5000. anyone know where i can get good bbs for cheaper than that?
They're on sale...


http://www.airsoftgi.com/product_info.p ... ts_id=2871

beyond that, check Ebay

http://cgi.ebay.com/24000-0-12-gram-6mm ... 35a6721dd7

For range, go with .20's For volume and price, go with .12's