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BB comparison


sirrith

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I don't know how the really expensive scales work, but my guess is that the cheaper ones, like say sub-$100 scales that can measure in grams are really measuring pounds (i.e. weight) then converting to grams (i.e. mass), and thus, if they did have the accuracy to say micrograms, the difference in gravity between two locations could make a difference. Gravity in London is 9.812m/s² where the gravity in NYC (closest city to me on Wikipedia's entry) is 9.802m/s². That 0.1% difference will actually show up already in tenths of a milligram. So, if there is already variation on the order of 10's of milligrams, knowing micrograms is kind of pointless, right? It's not like the entire firing system in an airsoft gun is going to be so consistent that a difference in a few hundred micrograms is going to affect things as much, right? It would be nice to know whose (mine or newcomer's) variation in SGM weights is "more accurate" though.

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Not sure exactly what it is where you are, but http://en.wikipedia.org/wiki/Earth%27s_gravity has a list of some locations. Between the largest and smallest, there is only going to be maybe a difference of less than 0.5%, meaning a difference in maybe 1mg or 2mg which is going to be as much as the error in the scales that we have, since they are probably not sophisticated enough to deal with gravity when measuring mass.

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Ok, so you have a 20k scale. Unless you actually get around to weighing some bbs, it's quite pointless to post up a pic about your scale, no? No offence but posting up some pics of a pretty scale doesn't really say much about "this is how weighing is done".

 

None taken. I took the photos mainly for a laugh, because it's true that when it comes to airsoft tolerances a postal scale would work fine. To defend my post, I think the marble table, forceps and anti static device say a little about how it's done. None of that stuff is actually "mine" as you might suspect.

 

I actually posted some weights a few pages back for the Bioval .27s, but you snipers don't care much about mid-weight bbs.

 

All I have are various cheap .25s, BBBMAX, Javelin .36s, and some Javelin .43s on the way. If anyone's interested PM me and I'll gladly weigh anything I'm sent.

 

...the difference in gravity between two locations could make a difference....

 

A microbalance has to be calibrated and qualified where it sits, and every time it's moved. Plus a yearly calibration and a performance check (using certified weights with their own calibration schedule) every day before it's used. The calibration compensates for environmental variations so a gram is a gram no matter where you are. /geek

 

I suspect even the nicest BBs vary from batch to batch, more than enough to account for the differences you're seeing.

 

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Normally this wouldn't matter. If I set my gun up for 500fps (site limit with a .2) with the hop full off & use sgms. like I used to.

 

At about 6 clicks of hop, my position for sgms, the gun chrono's about 505fps. To get a Devil .4 to go flat for 80m, I set hop to just over 3/4 full on. At which point my gun's chroni 535fps!!!!!!!!!! :(

 

Greg.

(quote trimmed)

 

 

Theoretically to counteract the "power creep", setting the rifle up based on a power to ammo weight calculation would be best I think?

 

Which if I remember right, 500fps with a .20g is 352fps with a .40g.

 

 

I dunno really, just thinking out loud. :rolleyes:

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Just today, I came across a microscope that comes with a software and image capture capability. This got me very tempted to buy it just for the sake of examining bb surface, sphericity, barrel surface, etc at 200X magnification. It can also be handy for other purposes. Haha, anyone done it before?

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Anyone know of a BB that can only be seen through night vision?

 

I'm looking for a BB that will only "glow" when seen through NVG's, after it has gone through an IR tracer unit (not UV light)

 

I tried using normal green glow in the dark BB's, looking at them through a PVS-14 after illuminating them with an IR laser. Didn't do anything.

 

I would bet that the BB would need to be coated with something, just don't know what.

 

Anyone have a thought on this?

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Not able to try just a tracer unit ? Perhaps a tracer mag?

 

When I fired madbull green tracers through my tracer unit, while lookin through a russian NSPU scope, they lit up with a very bright green tail and I followed it all the way to the target in the pitch black. Amazing!

 

Although, being a tracer round, everyone else could see it aswell. lol

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Alright, I'm gonna try those after I run out of my guarder .28's. Im currently building a semiautomatic m140 aeg and going to do some accuracy tests when I get a new motor..

Chronoed at 145m/s (480fps) with .2's,and its pretty accurate for an aeg already, but not nearly enough for my needs :D

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