Airsoft Physics 101

This post is undoubtedly going to kick off another round of "mines cost more than yours so my bbs go 400ft farther and will last for 37years"...

OK maybe thats an exageration...

I would simply like to relay my experiences and relate them to the realities of airsoft.



1. All airsoft guns operate in the same way (With a VERY FEW EXCEPTIONS). This means that they all fire a 6 mm bb (Usually wieghing .2g) at velocities rarely exceeding 400 fps (Mostly around 300-350)
The vast majority of airsoft guns DO NOT have rifled barrels. I will talkabout why this is important to gaining a good grasp of the realities of airsoft.

This means, that there are certain parameters that all brands of airsoft guns operate within.

My expereince has shown that 150' is usually the MAX effective range for most airsoft guns using shooting angles (Less than 10 deg of muzzle elevation). 150' is truly the apsolute max, in reality most guns seem to perform their best at ranges of around 100'.

So what does this all mean and why am I saying it?

It means that no matter what airsoft gun you have, small, large, cheap expensive, you will not have a night and day deviation in performance.

(The possible exceptions being mini airsoft guns and or very low powered springers).

So here is the moral:
Yeah, you spent $350 + on that sweet full metal rig from XYZ brand, high priced manufacturer... BUt, just because you did, does NOT mean that you will be able to reach out and hit a target at 250'. Nor does it garuntee that the gun will "LAST" for a certain period of time. If you abuse the gun it may not last a year.

Likewise, that $100 Chinese clone may still be able to "Run with the big boys". After all they are simply reverse engineered versions of the "Big boys".

remeber, its all the same underneath (THere are no differences in cartridges, or recoil mechanisms or anything else.)

Therefore, bc the bbs are basically the same weight, and basically travelling at the same speed w/o rifling, the only real differences are aesthetic. Logos, gun finish, etc...

2. Barrel length is not everything in the sport of airsoft. (INfact it can be a detriment.)

Those of you who have been around for a while have no doubt heard me rant on this subject...sorry

To those of you who havn't here it is.

In real steel firearms, barrel velocity is usually joined at the hip with cartridge size and charge.

IN other words, a long barreled sniper rifle was a sniper rifle for (Among others) two major reasons.
a. LARGE CARTRIDGE capable of travelling at a VERY HIGH velocity.
b. Long specifically RIFLED BARREL perfectly suited for putting a spin on the non spherical metal projectile. This causes gyroscopic force which helps to stabilize the projectile. (Note: airsoft bbs are spherical and usually do not get shot out of a rifled barrel).

So, the sniper rifle usually has very high accuracy at very long ranges with a generally low ROF.

By contrast, the SMG fires a reatively low powered cartridge at relatively short ranges. This means that the range and "Terminal effectiveness" is relatively low in comparison to the sniper/marksman rifles.

Now, in the real steel firarms, the differences are so great that the sacrifices one must make to use and operate the larger guns, is worth it.
(You have to lug a huge honking piece of hardware, but, you can hit your target hundreds if not thousands of feet away).

By contrast, the SMG is favored when long ranges are not an issue and ROF and light weight is critical.

Now here is the hypothetical question...
"Wouldn't a sniper prefer to have a SMG sized and weighted sniper rifle with the same powerful cartridge?, and wouldnt the CQB fighter like to have a SMG with a hugely accurate capability?

The answers are usually "yes" and "Yes".

Now here is why I set this whole comparison up.

In airsoft, the sniper with the bolt action 10-14 pound airsoft gun is not going to appreciate the same significant advantage in range and power as in the real world firearm counterpart.

This type of player will gain , perhaps 20-40 ft of range using the heavier bbs, and with those heavier bbs will have a velocity of not much more than 40-60 fps advantage.

BC the bbs is still less than half a gram, wind, humidity and even temperature can still have a TREMENDOUS effect on the unrifled sphercal bb's trajectory. So even with that tight bore and that upgraded hop hup, a bb flying over a particularly hot section of sand/concrete may still fly off course. Not to mention what happens if there is a breath of wind.

SO, here is the point.

If you are playing to the sport and are looking for every possible playing advantage, the smallest, most compact airsoft gun is going to be the type of gun you buy.

It will provide the least amount of arm fatigue, it will get snagged on items in the field the least and it will be the most maneuverable.

Now, if your goal is historical reinactment or even simply having a replica, then this argument does not apply to you.

If you play to the sport, and accept the physics of airsoft, then it quickly becomes clear that he who has the greatest mobility, maneuverability and is least wieghed down will be in the best position to win.

I think you mean yards, not feet there, chief. Real steel rifles measure effective range in meters/yards.

Also, the main issue that decreases effectiveness in airsoft is the seal around the pellet as it's travelling down the barrel. Maintaining a solid pressure curve throughout well give you a (very minor) range advantage, so assuming all things equal, an M16 replica will outrange an MP5 replica by a little less than 10 feet when using a very high quality tightbore.

This applies to springers and electric replicas mostly, as classic airsoft CO2 replicas can have some wicked range on them, thanks to a decreasing power curve over distance using a pressurized gas.

Don't forget the batteries to power the system: Not all compact airsoft replicas have the battery storage space for lengthy OP's.

LOL "Chief"...not too sure about that one.

Chazbot, I appreciate you looking out for me, but I usually write what I mean.

Last I checked 1 Yard was 3 ft, therefore, thousands of ft mean thousands of yards.

"Usually measured in yards"
Perhaps, it is immaterial to my main point.


As for the seal around the bb, this is the same principle applied in paintball.(And I believe you are correct...but I am taking it a step further).

After a certain distance, the length of the barrel begins to put too much drag on the projectile, thus decreasing the velocity.

There is a sweet spot, though in truth I do not know precisely what it is (My thought is around 10-12 ").

Some people have claimed that the gas powered bb guns can shoot farther, I have not seen this personally, so I will not argue this point in depth.

A "Decreasing power curve" is a unique phrase, which I have not come accross in this context before.

Frankly, I don't think the bb cares what type of compressed gas is propelling it, once it leaves the barrel, its still a .2g(ish) bb subject to wind and any other variable.

The only argument that I can see would again be similar to the Low Pressure set up utilized in paintball. Where in, low pressure (Relatively) was used to propel the bb to the same velocity using less force. This was more gas efficient and seemed to "Bounce" the paintball less...
But lets not forget... this is what every round projectile does within the barrel.(BB gun, paintball gun, Musket, smoothe bore cannon, etc...)

/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\.

It bounces, even with the tight bore, the bb is still bouncing, in a manner of speaking, of certain points within the barrel. Therefore, the only thing a the tight bore barrel is doing is recucing distance between the bounces.

Battery life is a valid point. Too small = too little battery capacity.

However, the 8.4v 1100-1500 mah utilized by the MP5 and G36C provide acceptable performance. (These are some of the most compact airsoft guns on the market).

even the 1050 (Or so) Mah stick type battery in the UMP 45 provided outstanding performance.

OK, but that can be quite misleading if you don't specify feet, as real steel measurements are in yards or meters. 300 yards of effective range may be equivalent to 1000 feet (roughly), but virtually all ranges and performance testing is based on the yard (or meter) as the base unit.

Unless you are doing it to just be different. In which case I can just as easily start saying meters per second like our UK and Japanese friends.

Different gases give different pressure curves over the volume of applied force (most cases the length of the barrel). While all decrease in pressure as the volume of the pressurized region increases, there are significant differences in operating pressures, over-pressures that can lead to failure-to-extract, to simple explosive leftovers that cause fouling and induce more friction than normal. CO2 versus propane for example, in classic replicas.

You're right in that the pellet doesn't care, as once it leaves the barrel more than a few feet it's the mass and the inertia acting on that mass that determines range and accuracy, but the force that initially imparted to the projectile and (in the advent of the hop up system) the back spin imparted that gives it the kinetic energy to leave the replica to begin with.

I know that classic and CO2 airsoft replicas have lower overall fps (which is adjustable anyway) and usually much higher rate of fire thanks to their mechanism.

Chazbot,

you are missing the point with the ft v yds.

It is immaterial to this post and I am letting the matter die.

As for your discussion on the gases interaction with the bb within the barrel, I am not sure what you are saying.

We all know that the compressed air/gas is the thing that exerts endows the bb with kinetic energy.

THats why it moves.

This is what has me confused...

" but the force that initially imparted to the projectile and (in the advent of the hop up system) the back spin imparted that gives it the kinetic energy to leave the replica to begin with."

?

Regardless, if we agree that the bb responds the same external factors as a bb propelled by compressed air, I think the whole issue is moot.

This thread is intended to illustrate popular misconceptions about barrel length (ANd gun size) in airsoft and max effective operating parameters that all (Or nearly all) airsoft guns work within.

I.e. an airsoft sniper, is not as capable of hitting a target at greater ranges than a player with a SMG as in the real world.

Put another way, this thread is tasked with illustrating that the variance in performance is not nearly as great as many would have you believe.

Also, bc those variances are so small the sacrifice of carrying a heavier, bulkier airsoft gun is not nearly as worth the trouble as it would be in a real world environment.

When you consider this, then the question is, why would I use a bolt action, if I will have to engage at ranges similar to guys with full auto guns. Then you are tactically at a disadvantage.


I don't want to make it seem like you should never get a sniper rifle. They have their place and certain advantages (They are quiet)

But if you are thinking about being a "sniper", understand that you're skill will have to be better tactics, because in truth, you will not always have better range.

I used to disagree that barrel length had little to no effect with accuracy. However, I looked into it.

I've noticed that most kills that went on in the field were based on the more compact guns. I believe, this is due to maneuverability. I've also concluded, that the bonus of distance, is practically negligible, when comparing something like the AK47 to the M4. (455 to 407, based on prometheus' measurements.)

That's really why I don't use a dedicated "sniper rifle". A majority of time I play a sniper position, or sometimes the exact opposite: Right out in front of the group. And I needed a gun that did both. Not to mention that an electric sniper rifle (like say a m14) wouldn't be that much better than my M4. (comparing barrel lengths again) Basically, it just comes down to which gun you like best. Some people I know would still prefer a well L96 to an AEG, just because of the style of the gun. (as in, they'd rather get an awp and a backup than get one AEG that they didn't necessairly like the look of).

Then why not state simply that "All airsoft replicas generally perform the same, ignoring all associated factors that are normally important for actual firearms. Get what you like and have fun."

There's always going to be someone who asks "WHAT AM BESTE GUNS" and a simple "they're all the same more or less, just get something that appeals to you." Is a simple, digestable answer. The physics behind it are irrelevant to the average airsofter.

As for the quote, I'm saying that in the same mechanism, different gases exert different pressures, and will give you subtationally different performance. Before hop up was around, you usually had to mess with your flow control valve, or opt for a different gas.

The gas M700 replica from KJW is a pretty nice sharpshooting system. I'm thinking on getting it too, along with an Echo 1, but at the same time, I'm almost never in a position to do any sharpshooting.

Also: "moot" means "worth debating".

Everything regarding personal choice etc... that you have just said is what I have stated in one form or another already.

That you are on the same page in this matter is good to see.

As for the gas guns, my experience with gas powered airsoft guns is limited.

I admit my argument here is theoretical.

I am drawing on my experience with lead pellet guns, copper bb guns and paintball using compressed air and co2.

As I see it, the propellant makes no difference.

Here is why.

As you have already conceded, propellant aside, once the bb leaves the muzzle, all is equal.
Therefore, the propellant used to propel the bb to a given velocity is irrelevant.

Using cars again, it does't matter if you ran through every gear, or powershifted, if you got to the speed you wanted, at the rate of acceleration desired, there is in effect no difference to the method of acceleration, and then maximum velocity.

Getting back to airsoft...

Even before, the bb gets out of the barrel, it is still bouncing around inside the barrel. Whether its red gas, green gas, co2 or simply compressed air the principle is still the same the bb still goes "Bounce"
/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/

Therefore, any difference is so minute, that it is virtually non-existent.


So unless you are telling me that the gas used in the guns you cite, puts some additional force to work,(Like a horizontal rotation on its axis to cause gyroscopic forces on the bb), I cannot see the difference.

(Even then I would be skeptical bc the barrel on the market that does this has dubious improvements in overall accuracy at varying ranges.)

I have already mentioned the LP set ups that I have encountered in paintball, but the dynamic was different. It was as much about gas efficiency as about percieved improvement in accuracy.

The LP set ups deformed the pliable, soft outer paintball shell less, therefore there were fewer dents and deformities to pull the paintball off course.

Obviously airsoft uses a much harder projectile, so this is less of an issue.

The M700 still does use hop up as I understand, so, if indeed the gas propellant has some magical effect, surely it is countered by the presence of the hop up unit.

i diagree that every airsoft replica shoots the same. is it not fact that if you have a barrel that is just tight enough that it wont let any excess air out up agianst one that is a cm to big, the tight barrel will obviously go farther. i agree with the length of a barrel no having much effect though. and another thing is why i would rather have a CA over a E!. first off is that i have a E1 and am not bashing them in any way, but there internals are obviously not as good as CA or TM. i know E1's will probably shoot around 50 fps more but i am willing to sacrifice that if my gun will last longer, because it doesn't matter how well you take care of your gun, if your internalls are not as good of material there gonna break sooner. so if i was offered a CA or E1, then i will take the CA because of its internals. thats answering the 350 dollar question

Barrel length is not a factor but airsoft guns designed to be long range type guns (M16,G3,M14..) will have better accuracy at longer ranges than CQB guns. Why? the MP5 for example is definitely a CQC gun, so, the iron sights will be made for close up and personal and medium range shooting, while lets take for example the M14, which has iron sights with a small aperature for longer range shooting, will be more accurate at longer ranges than that of an MP5 imo. Also sniper rifles are better for sniping than lets say a M4, because they are made to be for long range shooting, so they will have large size scope mounts and will have large butt stocks to accommodate that huge monster scope that snipers mount on them.

I'm coming from classic airsoft and how they worked.

The hop up in the KJW works similarly to a hop up in a pistol, from what I can determine.

And the propellant does make the difference (as far as classic airsoft goes anyway) because there are different operating pressures internally. Constantly firing two identical gas powered M16's from Sun Project with different gases nets you two different results. The CO2 one will fire a bit harder and won't condense as fast as the one firing propane. The one firing propane will have a more consistent grouping, and won't put as much pressure on the valves or o-rings. Rate of fire, and parts wear are pretty important.

For the car analogy, one would get better gas mileage, and would need less overall preventative maintenance. Between two equal cars, you'd generally pick the one that will save you $2.00 at the pump each tank.

More to it, if we agree on the same point, that airsoft should be fun, why are you spending so much time refuting me? I'm mostly just putting up some information, and you go off on some crazy rant. Where in the original post that I made did I disagree with you?

You even agreed that my pointing out that battery and barrel fit are important factors when it comes to range and performance. Your idea of them being negligible doesn't hold in real life either, since that tiny (ridiculously tiny for $55 upgrade part, sheesh) 0.04mm difference has a tangible change in both fps and in effective range, not to mention grouping.

Chazbot,

as others have begun to post, I am going let this argument end.

I had stated that all airsoft guns have effectively the same range.

You then said that some gas guns have "Wicked range".

Now, perhaps I mis understood this, however, I took it to mean that the had a range above and beyond that of a normal battery powered AEG.

THat is where the disagreement occured.

Now,

As to the comments of Overmedicated.

LOL...

Everything you just said is exactly the type of misconception that I am attempting to expose.

ALL airsoft guns, will have a max effective range of 150'.

IT DOES NOT MATTER WHAT MODEL!

In an M14 the sights are meant to be used at much greater distances than the MP5.

BUT!!!!!!!

BC the max range is only 150 fit it does not matter!

The grouping will be no tighter, therefore, any advantage that the sights might provide (And lets be honest, on full auto, most people simply walk the fire to the target) would be so minute that it is non-existant.

(I will concede that a scope can improve your accuracy based soley on the magnification advantage)

HOwever, a scope aside,(which does not make the gun more accurate, it only allows the shooter to be more accurate)

The ONLY advantage to a larger gun is perceptual!


It is not inherantly more accurate, more powerful or anything else.

It is simply exterior dress up, that is all.

Now, as I have already stated, if your choice is based soley on personal choice, then there is apsolutley nothing wrong with that.

If you just like the feel, or want to have a replica of your favorite gun, thats part of what airsoft is all about.

BUT!

A "CQB" airsoft gun will be as accurate as that tricked out battle rifle.

Now, in regards to the issues about CA vs. E1.

As I have written in other posts, there is nothing that I can say to change your mind.

You want that gun, you feel that the extra $ is worth it. Thats fine.

But, until I see a study that shows exactly how much longer the CA will last, I cannot buy the "Its more expensive so it will last longer" argument.

If you know your way around the mech box, you can fix anything, and or simply replace it.

In fact, if you had a failure in the E1, you could simply swap out the parts with upgraded parts at a cost that would no doubt be dramatically lower than the CA, ICS etc...

That negates the question of which model will last longer.

Now, it can be said that having to do that is a hassle, and therefore, you would prefer to spend the extra $ upfront.

Thats fine.
But, contrary to what some have said, TLC will keep nearly any mechanical machine going indefinitely.

If you have the know how, replacement and swap out are relatively simple deals and you could end up with an airsoft gun that would be superior internally to the more expensive competition.

I think that this principle is so hard to swallow, bc people like to think that the stuff they spend more money on is truly getting them more.

To be fair, it is getting you more, but it might not be as much as you think, or at least not getting you what you think in the places you think it.

I meant that it would make the shooter more accurate, sorry I wasn't clear about that.

Play with a Sun Project and compare ranges, generally the SP will come out on top more often, but the difference is only just noticeable (about 10-20 feet more). Enough to notice, not to matter.

TLC and good preventative maintenance will always extend the life of a replica. Exactly how much more maintenance a replica needs and how often it is performed as needed, versus some other brands or designs is still a curious point.

Maybe a thread that shows trends of upgrades or problems for different brands would be something neat to have?

yes, also have you seen the video of the Asahi M60 hit a target at 300ft?

I've never had the chance to play with the gas machine guns, but I hear very good things about them.

I have seen this on Youtube.

However, the vid I saw, did not show the muzzle elevation that was being utilized. (It only showed the target )

I heard that he fired in half second bursts in the vid, out of those bursts (Maybe 20 bbs) 1-2 hit.

Now, it is impressive, however, I cannot see whether he is "mortaring" or if he is firing with a "Normal" muzzle elevation.
(less than 10-15 deg).

The gun is an impressive bit if engineering and it is also expensive ($800 from what I have found)


...

To say the least, this is an "OUtlyer" in the averages which I have already cited.

It still proves Classics rule!

Frankly, I am surprised that this type of gun (Gas/ Compressed air) has not seen more wide spread popularity.

I hope to be able to get a gas powered Mac 11 for testing.

They used to be popular until TM invented the V1 gearbox and made the first AEG, thats when Classics went under.

Thing about gas is that it's expensive to purchase in the bulk needed for extended airsoft, it's a more than a little volitile, and you simply don't get the operating life of a battery pack (a tank of CO2 will last only a few thousand rounds, whereas a good battery is twice that). And you can easily recharge a battery in the field or carry 1 or 2 spares in a small pocket.

Lastly, CO2 tanks can get cumbersome to lug around to longer airsoft games. Since the tank is reuseable, but not cheap to refill, it winds up costing a decent amount of money.

Paintball is similar in pricing I think.

Yep, they use paintball C02 tanks, I used to be a paintballer(please don't hang me lol) it costs like 2$ buck to refill a small tank.

For those that don't think $2 a fill is pricey, imagine paying $2 every time you charge a mini battery, or $5 to charge a large battery.

It adds up pretty quick.

lol it does

And screwing with a regulator and control valve, worrying about hose pressure, whether brass or copper hookups are better, making sure you don't sit on your bottle satchel, etc.

lol, fun times. Most of the fun was being super loud.