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AK DMR?

I get the distinct feeling that I'm feeding a troll, but since you're trying to use geography to justify stupidity I'll type a few lines in defense of American airsoft. I play milsim airsoft in multi

Refinished the stock of my NPO VSS so it's closer to the color of the VSS seen in some of the Beslan school hostage crisis.   -Piano

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An AEG doesn't push as much as down the barrel, only the amount allowed by piston travel. A p* with a high Poppet dwell can more and more air down that long barrel, putting more force behind the BB, causing it to fly farther.

 

Exactly. Because more air, as you said, equals more force, equals HIGHER MUZZLE ENERGY.

 

If that bb comes out of the barrel at 400fps, it doesn't matter if it is an AEG or a gas system, it's still AIR and the laws of physics still hold true.

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Joules and FPS are different. Joules = the force of the thing thrown through the air, and FPS is the speed. If the BB is pushed with more air, which means it has all that extra force behind it, means it will go farther. Take any AEG, a gun with a longer barrel usually has more range than a short one, due to air compression behind the BB for a longer time.

 

P*s can have even more compression behind the BB, meaning you can shoot a .4 out of your barrel with a ton of force, a lot more than an AEG which has a fixed amount of air compression due to piston length.

 

You can throw a foam ball which weighs very little. You can throw it very hard, but it won't go as far as something with a bit of weight behind it.

 

An AEG pushes out a fixed amount of air. It pushes out a .20 the same way it pushes out a .40. You take a .40 in a polarstar, turn up the amount of air follows the BB down the barrel, resulting in the BB not losing force as fast as an AEG. Force is what decides range, along with other factors. Speed of the BB does not play as big a factor as force.

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Short stack, you fail physics forever.

 

Joules are a measure of ENERGY. Force is the product of mass and acceleration.

 

When the BB leaves the barrel, it will no longer have any force from the gun acting upon it.

 

We measure MUZZLE ENERGY in joules. The energy the bb has when it leaves the barrel.

 

ENERGY is 1/2 (mass x velocity^2). Therefore, if the same bb (ie, same mass) has the same muzzle energy, it will have the same velocity (ie, fps).

 

What is happening in your P* is that it is firing at a higher muzzle energy. Chronograph it and figure out how many joules it shoots with those 0.4g bbs. They will travel just as far as an aeg firing the same muzzle energy.

 

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Short stack, the amount of air an AEG pushes is irrelevant, the amount of force applied to the compression of that air is what is relevant, that is why different spring tensions increase muzzle energy or as newer players see it, increase FPS.

 

However if you have a .4g BB shooting 400FPS, it will be shooting at roughly 3 joules, which is the equivalent of a .25g BB shooting 510 FPS, a projectile shooting 3J has the same energy, but can vary in weight and velocity.

 

Projectiles are measured in energy which as darklight said is a function of mass and velocity, AEGs can produce the same muzzle energy a P* can, however the P* can be programed to shoot at different energies on the fly where as an AEG needs to have springs swapped out, and I think that is where you are getting confused.

 

You may also be thinking about BB dwell like in GIM GBBRs (the theory that a heavier BB is in the barrel longer during the expansion phase of a compressed gas imparting a higher muzzle energy onto a projectile of greater mass than one of less mass), well unfortunately P* don't really have much gas expansion in the barrel like a GIM GBBR does, as expansion takes place in the regulator and the engine, so unlike with a GIM GBBR, P*s do not produce much of a higher energy with a heavier BB.

 

EDIT: this chart may help you understand muzzle energy a bit better

http://www.texasairsoft.org/content.php?127-Muzzle-Energy

 

 

As another rule of thumb inner barrel length does not count towards DMRs, if we were looking at inner barrels or even range, I could post up a R hopped 10 inch outer barreled 416 that shoots 280ft, but thats not the case in this thread.

Edited by frogfish
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I'll give you that polarstar rifles get less energy than some gas rifles (900psi WE m4's, i'm looking at you), but it's still enough to be a problem.

I ran mine at the following:

70psi

black nozzle

363mm barrel

Lowest dwell (think it was 15dP)

 

I got 110m/s with 0,20 and 90m/s with 0,40. That's a 40% increase in energy from 0,20 to 0,40 (Most fields here run 1,69j max on auto rifles, so 90m/s 0,40 was the goal).

 

When Short Stack is firing a 0,40 at 475fps, that's 4,2J, or in terms of tune up, a M210 Fullauto AEG. Frankly i find it frightening that people buy polar stars and aren't aware of what joule is.

I guess it's up to the field owners to educate and regulate the use of it, but it's kind of cheating even if the field owners just aren't aware of joule. I get it's a "DMR" rifle and as such 4,2J isn't wrong, but the owner doesn't exactly radiate waste amounts of knowledge about joule.

 

 

We have the same problem here with the Dan Wesson revolvers and the sar10 CO2 rifles. It's 200$ for a rifle that shoots 4J. With 0,20. Then newbies buy it and think it's ok. They don't realize that when they put in a 0,40 it hits over 7J.

So whenever we spot someone with one of those two weapons, they get chronoed and get a crashcourse in what joule is and how their safety distance is.

The Dan Wessons are almost non existent by now. They tend to have a longer MED than they can hit at, so...

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What I'm trying to say, is that a polarstar, thats at 400fps w/ .20, but using .40s and the right FCU tune, will shoot farther than an AEG with the same specs. I'm not very good at physics, but I tried to explain my reasoning why it shoots farther. Maybe I'm wrong on that, but they do shoot farther. And I do understand there's a joule difference.

 

Sorry if I looked like an idiot, I was just trying to explain my reasoning

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considering that a P* uses the same hopup unit as an AEG I doubt that, also comparing several P* against fine tuned AEGs there was no difference in anything beyond sound and trigger response.

 

Energy of the projectile dose not determine range as much as a well tuned hop-up.

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If you measure your bullet speed (and therefore kinetic energy if you factor in the bullet mass) after it exits the barrel (so....how you measure ALL bullets fired from guns) there's no other force acting on the bullet except for gravity and air resistance from it's flight. Soo if there's no hop up applied (therefore the bb does not have spin applied to it) there should be no difference in it's flight (THEORETICALLY) as long as the mass of the bullet and the muzzle energy measured is the same.

 

HOWEVER, given that we have hop ups that imparts spin on the bb bullet; the above statement may not hold true. Firing a 0.4g bb at 2J from a gun with no hop will not give the same range as a 0.4g bb at 2J with hop applied, assuming you're shooting both setups parallel to earth.

 

With hop applied there is more ENERGY imparted on the bb as the bb spins in it's flight, which requires additional energy to do so (compared to a bb that did not receive energy to spin). However, given that our chronographs only measure speed, we can only measure the energy of it's flight towards the target, not the energy required to spin the bb (which if we could, we can get a closer estimation of the actual amount of energy imparted on the bb in the chamber just before it moves).

 

Short stack, it doesn't matter whether it's a P* or an AEG, once the bb leaves the muzzle, short of any turbulence messing with the flight of the bb (or having under volume air pushing the bb through the barrel), and having the theoretical same bb, hop up applied, and same environment the bb flight is in; the flight path and range would be the same.

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I'm beginning to think he is trooling, or just a product of the US lower education system.....

 

I would say not understanding the basic physics is unforgivable, but if we start discussing pneumatics...

 

 

the thing that worries me is that this is the type of player who would abuse the abilities of the P* system, compromising everyone's safety, and be too dumb to realize it.

Edited by frogfish
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DarkLite has this 100% correct.

 

Shortstack, it doens't matter WHAT is pushing the BB down the barrel, it could be an AEG piston, a P* gearbox or me with a rubber mallet. The chronograph reading is AFTER the BB has left the barrel and there are no further forces accelerating it.

 

I think you're thinking on Dwell time, in that you can adjust how much air is behind the BB, what you are saying is a P* shooting 200fps with 0.2bb's will produce xjoules of energy. a P* with 0.4g bb's will producethe same FPS, but MORE energy.

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As I said before, barrel dwell in P*s is minimal, most of the gas expansion happens before it hits the engine. Even as such dwell in most GIM GBBRs isn't that severe, it would produce a lower FPS but still a higher energy.

 

What may be going on is the same thing that some Asahi's used to have issues with, the BB weight alone would increase the pressure build up time in the engine causing greater psi, resulting in the same FPS regardless of BB weight, however the P* isn't actuated based on pneumatic pressure its electronic, so that shouldn't happen, once the weapon hits a prescribed pressure the trigger opens the valve....

Edited by frogfish
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Well this all escalated quickly. Should I get involved? My intelligence level may be questioned. :rolleyes: Anyway, numbers for anyone's consideration hopefully that will clear up everything. Poppet dwell is all the way up. Note the gun is running in closed bolt mode. Chrono is an xcoretech.

 

.2g/ 473/ 2.07

 

.3g/ 412.2/ 2.36

 

.36g/ 398.8/ 2.65

 

.4g/ 385.9/ 2.76

 

and for comparison's sake, I switched it to open bolt.

 

.4g/ 377/ 2.64

 

 

The way I see it, an aeg and a polarstar should perform similar assuming same hopup/energy/bb. Consistency is easier to maintain at higher power levels with a p* in the long run.

 

I obey the fps limits at the local fields, that is, I am mindful of the energy level of my gun using the bb weights I use. Spirit of the law and blah blah blah. I think chronoing should be done in joules with heavier bb's, but whatever.

 

So are we defining dmr's by appearances or performance now? :locked:

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To your bottom paragraph, that's what I'm saying. I put a .2 in my p*, and chrono at 400fps. Put a .4 in it and I'm down to maybe 380 or so. Using heavier BBs in a p* brings more range. Whether physics says so or not I shoot further than an AEG with the same specs.

 

Also, sorry I don't know physics. That doesn't decide whether I can use my gun or not. I understand p* make more joules at high BB weights. What I don't understand fully is why my gun shoots farther than AEGs with the same setup.

 

And we were having a perfectly fine, mature discussion and you resort to insults? Lost a lot of respect because of that.

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You are comparing two different energy outputs. .4 at 380 fps is equal to about 2.67 joules, but you're comparing that to 400 fps with .2, which is only 1.48 joules. So your gun with .4 at 380 fps has to be compared with an AEG that shoots 536 fps with .2s.

 

To maintain the same energy, you should be aiming for ~280 fps with .4s

Edited by dwong
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Exactly. Polarstars are different than AEGs and because of that give a lot more range than them.

Only because they are imparting far more energy to the bb, which is dangerous unless your site limits are measured in joules (energy) rather than a limit basef on fps and .2 bbs, as you say, because the polar star will have much higher energy output with a heavier bb.
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I rarely stoop so low, but ShortStack, you are an imbecile, a genuine idiot.

 

You are not shooting FURTHER than an AEG, you are shooting HARDER.

 

You should not be allowed near any gun unsupervised, airsoft or not.

 

Your gun is breaking site rules, you are not shooting further becuase P* is better, you are shooting further becuase your BB has more energy behind it.

 

Your P* at 380 fps with a 0.4g BB is shooting the same as an AEG shooting 380fps with a 0.4g BB.

 

Now how do we work out how fast you're shooting with different weight BB's?

 

We use JOULES, this is a measure of how much energy the BB has coming out of the muzzle.

A 0.4g BB takes TWICE as much energy to push as a 0.2g BB being TWICE the mass

Now there's more to it that just weight, hop-up, etc will affect the energy prior to exiting the barrel

but you are essentially shooting at 536fps with a 0.2, WELL above any site limit.

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Now there's more to it that just weight, hop-up, etc will affect the energy prior to exiting the barrel

but you are essentially shooting at 536fps with a 0.2, WELL above any site limit.

 

Easy there, he is in the US. 536fps is a legal power level in so far as a lot of the out door sites here go. With a 100ft med...and full auto disabled. Shortstack, I don't think anyone here is disputing that a polarstar can impart more energy on a BB. Its that given an aeg and a polarstar, both imparting the same level of energy on a bb, both will be able to achieve roughly the same effective range.

Edited by sniperelite7
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Not to jump on the bashwagon, but i gotta admit, he's a prime example of who shouldn't be sold a polar star. Little knowledge of airsoft and too arrogant to learn the tools used.

I guess the point is; ignore the people who don't care and blame the fields for not filtering them out. They should update their rules to modern ones and enforce them properly.

It's not hard really. Most fields here have switched to a raw joule limit, and it's actually simpler to enforce than the old methods.

 

Perhaps Polarstar should include a small pamplet educating people on what joule is. This is the kind of situation that gets their product banned from more fields, so it might be interesting to them.

 

If anybody know where Short Stack plays, please write to the fields and inform of this cheating (in a constructive way).

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Gentlemen, please - we all had to start somewhere and I'm sure Short Stack is not the only person on this board to have posted ill-advised comments.

 

Short Stack, read what they are telling you about joules - in this case the energy the BB has as it leaves the barrel - without getting defensive or offended. It's important, because your Polar* is currently shooting dangerously hot.

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Exactly. Polarstars are different than AEGs and because of that give a lot more range than them.

 

Yikes. This is why you are frustrating everyone, and they think you're an idiot. The polarstar, like EVERY OTHER gun, is forcing the BB out using gas. Based on your P* settings, your gun is using a lot more than what is necessary, so, when you put in heavier BBs it shoots harder (also farther).

 

This can be demonstrated with ANY OTHER airsoft gun, particularly with a short barrel/full cylinder. More gas than necessary=more power with heavier ammo. It doesn't matter whether the air came from a paintball tank or an AEG cylinder.

 

My CQBR AEG shoots harder with heavier ammo. My short barreled bolt action rifle actually has a higher FPS with a .40 than it does with a .20, due to a massive cylinder/barrel volume ratio. Most of my pistols have a higher joule rating when chronoed using heavier ammo.

 

What we don't seem able to get across, is that given the same muzzle velocity for a given ammo weight, a polarstar will NOT have more range. It's possible that you'll have more consistency than a sloppily sealed AEG, but that's it. Not one foot of extra range.

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