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Post by Obergefreiter Raimund on Apr 22, 2009 6:17:05 GMT -5
Anyone use .43 BB's before? Is it even safe to use .43’s?
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Post by lrich on Apr 25, 2009 1:10:08 GMT -5
i have, its safe to use them, provided that your FPS is safe with .2g's. They wont magically be more powerful, but remember, 400 FPS with .43's is a ton more than 400 FPS with .2's, so your FPS may drop off dramatically, depending on what you are using now.
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biged
Master sergeant
Posts: 468
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Post by biged on Apr 25, 2009 5:15:44 GMT -5
It's all about the Joules. (Power)
1.49 Joule gun will shoot 400 fps with .20, switch to .25 gram ammo you will shoot 355 fps. 1.86 Joule gun will shoot 400 fps with .25, switch to .43 gram ammo you will shoot 305 fps.
3.20 Joule gun will shoot 400 fps with .43, switch to .25 gram ammo you will shoot 528 fps, and 585 fps with .20.
///ed///
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2nd Bat
Master sergeant
Posts: 11,813
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Post by 2nd Bat on Apr 25, 2009 10:10:14 GMT -5
Normally the heavier the BB, the lower the muzzle velocity when fired from the same gun. There are some bizarre abberations however. Occassionally on long barreled gas powered guns you can find a rifle that will shoot the heavier Bbs at a higher velocity. Apparently the BB initially sets off a bit slower down the barrel and builds up increased gas pressure behind it. Hence as it leaves the barrel it does so with more power.
An example of this is the M1 Gas Garand by Marushin. It typically will shoot the .43 Bbs at a higher velocity than the .34s (The reverse of what you would expect) It was pretty impressive for the 300 or so rounds I got out of it before it broke.
Truthfully even if it consistently worked the .43s were probably generating too many jouels of power to be acceptable for most players as a semi auto gun. The 8mm does spread the impact a bit however.
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Post by bosco on May 7, 2009 10:00:56 GMT -5
Hi all.
So, ok for the energy problem (ENERGY!!! not power! Energy=J; Power=Watts).
BUT. There is a thing called terminal velocity, that is the velocity of the BB at the impact with the target. Without boring you with maths and other geeky things, at the same muzzle energy (0,5mv^2), heavier BB dissipate less energy in friction with air, so, at the same distance, an heavy BB has a greater terminal velocity than a light BB. Pain, or the "force of the impact", has a direct relationship with impulse, mv. What does this all means? It means that a heavy BB is useful for that "reach out" effect because one can feel it at a greater distance. BUT at short distance an heavy BB is more dangerous (read it hurts more) than a light BB because of its high impulse. Simply put, at the same distance and at the same muzzle energy, an heavy BB hurts more than a light BB.
I hope I made it all clear.
Sorry for making it long!!!
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Post by Obergefreiter Raimund on May 7, 2009 10:13:35 GMT -5
I want to use the .43 bb’s in the Tanaka Gas powered K98 rifle. Having experimented with them, I can hit a soda can at 135 feet 5 out of 8 shots consistently. As everyone already knows, the Tanaka is a high power gun. It shoots a .20 gram bb at a muzzle velocity of 580FPS.
Of course we use a 100 foot minimum engagement rule with such a gun. It primary use is for long range engagement. Regardless, those results are with green gas. We can use CH40, I think that is the name of it, and reduce the FPS to 400 with a .20 BB.
Anyway, I’m not really interested in the FPS of the bb. I’m interested in its steady flight path and range. Something the .43 bb has proven very well. I’d certainly drop the FPS of the gun with the use of a different gas to get similar results.
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Post by bosco on May 7, 2009 10:26:02 GMT -5
Ouch, 3,12Joule.
That's gonna hurt!!!
Ahhh, how I wish I were here.
Here in Italy we are constrained to a muzzle energy of 1,0 Joule (that is 100m/s -328fps- with 0,2g BB).
Anyway, you are right. Heavy BB tend to be deviated less than a light BB plus it has the "reach out effect" that I described in my last post.
Stick with heavy BBs and the minimum engagement rule. Winter time HFC22 (green gas) Summer time HFC134 (less powerful) Remember that gas pressure goes along with temperature.
Do not overpower your rifle. It may deteriorate gaskets and O-Rings.
If your k98 has the PCS system you can regulate the energy.
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Post by Obergefreiter Raimund on May 7, 2009 10:39:02 GMT -5
It doesn't have the PCS system. What I did is I rid myself of the entire hop up unit and placed a fix hope up on the barrel. The Tanaka Hop-up unit would break with green gas. It was made out of a cheap plastic.
Anyway… they made an all Aluminum hop-up unit later on. I might end up getting it. But yeah, I'd use the weaker Green gas in warmer temp. It helps bring down J's a lot.
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Post by bosco on May 8, 2009 1:13:27 GMT -5
Yeah, the plastic hop-up unit was crap!!! Unfortunately Tanaka parts are expensive but go for them.
And what has been said by 2nd Bat is true: heavy BBs tend to achieve greater muzzle velocity even at the same conditions (spring, barrel, gas pressure and so on). I have yet to discover why but it works!!!
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Post by Gordak on May 10, 2009 10:09:34 GMT -5
To me going .43 is just trading range for accuracy. -Sam
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Post by Obergefreiter Raimund on May 11, 2009 8:16:31 GMT -5
To me going .43 is just trading range for accuracy. -Sam Yeah, you lose a noticeable amount of range. However, the gun already out ranges most AEG guns. So, the increased accuracy is more than welcome. It allows you to one-shot a target the size of a soda can, with like a 5/8 or 62% chance, at 135 feet. The larger the target the better chance you will have to hit it. So… it is a good trade off in my opinion. And the gun still will put a round out about 200 feet even with the heavier bb.
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biged
Master sergeant
Posts: 468
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Post by biged on May 15, 2009 4:53:23 GMT -5
As joules increases, the BB weight shall also increase.
Get your gun chronographed with .20 gram bb's.
Minimum bb weight = FPS / 2000 (Any bb weight lower and the shot is inaccurate) Maximum bb weight = FPS / 1300 (Any bb weight higher and the shot range diminishes)
REMEMBER: Hopup enduces a magnus effect on the bb. In which you MUST adjust your hopup every time you change bb weights.
@ Obergefreiter Raimund, you have a 5.2 Joule gun, which translates to around 750 fps with .20 gram bb's. Using the equation you can use bb weights from .37 to .57 gram weight bb, so .43 gram bb's are rite on the money.
///ed///
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Post by Obergefreiter Raimund on May 15, 2009 5:26:23 GMT -5
Thanks ED. But, as I said, I'm going to use weaker gas regardless. It will shoot around 500FPS with a .20bb. Much less with a .43 or even a .30.
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2nd Bat
Master sergeant
Posts: 11,813
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Post by 2nd Bat on May 21, 2009 10:46:16 GMT -5
The reason the heavier weight BB occassionally shoots at a higher FPS (especially with long barreled gas guns) is the initial thrust is somewhat slower due to the added weight which places greater pressure (accumulating inside the barrel) prior to the BBs exit at the muzzle. Don't assume if you chrono a gun with .25s that the FPS will be lower with a heavier BB. It may end up being just the opposite. It's best to chrono a gun with the exact BBs you intend to use in the event and calculate what your jouells of power will end up being.
For those of you with high power, heavy weight rifles, for God sakes train with them, know your distances and respect the minimum engagement rules. How adequately can you estimate 100 feet? Most people can't (especially in the heat of an engagement) Long range weapons can be used safely and effectively in an airsoft event but frankly NOT by the average player.
A great deal of inertia is lost quite quickly with airsoft rounds so the impact at range is typically just fine but that same round up close can be quite devastating and injure someone. Be careful and be safe! Also if you're considering using the steel rounds understand that some states consider that a bullet and should you injure someone you could find yourself facing a very serious charge. This would negatively effect the entire airsoft community. My advice is stick to plastic.
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Post by Garrick Udet on May 22, 2009 8:28:42 GMT -5
If you are playing with a minimum engagement distance, remember that 16 paces = 50 feet and 32 paces = 100. Get used to pacing this distance off so you can get a frame of reference for an event. I understand that you're not going to call time-out, run to the guy you're trying to shoot and pace 32 steps back... but still, 100 feet is a lot closer than most people think.
Not super relevant, but I thought I'd throw it out there.
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