Longer inner barrel = better accuracy, why?

[Catman]

[..]

I guess GBBs are a bit less technical than AEGs. Either that or maybe it's not possible (or manufacturers simply don't bother) to regulate the amount of gas fired with each shot as accurately as it's possible to tune the air discharged from an AEG?

There must be stacks of gas venting behind the BB in a G17 because, as I say, when a friend fitted a long barrel to one the power went up by a MASSIVE amount.

[...]

<{POST_SNAPBACK}>

 

Just a thought (another crackpot theory ) - maybe this is because the flow valve in the nozzle isn't released until the BB leaves the barrel? Therefore more gas is being sent down the barrel than with a normal barrel, when the BB leaves the barrel the pressure drops, releases the flow valve which sends the gas towards the back of the gun, operating the blowback.

[Stealthbomber]

Just a thought (another crackpot theory ) - maybe this is because the flow valve in the nozzle isn't released until the BB leaves the barrel? Therefore more gas is being sent down the barrel than with a normal barrel, when the BB leaves the barrel the pressure drops, releases the flow valve which sends the gas towards the back of the gun, operating the blowback.

<{POST_SNAPBACK}>

A good point. Sort of.

 

I recently discovered that a KSC Mk23 doesn't shoot any air out of the muzzle if you dry fire it. All the gas is used to cycle the slide.

However, a G17 isn't so clever. It blats gas out the front all the time.

As you say, a properly working rocket valve might only cut off the power to the muzzle when the pressure drops off as the BB exits the barrel.

 

I suspect the quantity of gas used IS to de with the blowback though. I would bet it's either impossible to make a rocket valve that accurately sends gas out the front and back OR it's simply neccesary to send a big dollop of gas to actuate the slide.

Either way, it seems that loads of gas is spare (on a G17 at least) because the long barrel upped the power by an obscene amount.

[chas]

OK, thanks. But why does the TM M14 such an impressive shooting distance compared with i.e. an MP5 with the same FPS?

[Stealthbomber]

OK, thanks. But why does the TM M14 such an impressive shooting distance compared with i.e. an MP5 with the same FPS?

<{POST_SNAPBACK}>

Well....

 

At the risk of being contraversial, a lot of it could be in the perception of the owner.

I've seen G36s shoot just as far as G3s. Nobody lugging a G3 around wants to think he's wasting his time.

 

Having said that, TM have upped the power of their newer guns and also improver the hop-up as well.

 

The only way to verify this for sure would be to take a single gun and test fire it with every possible barrel.

The problem is that, as you fit a shorter barrel you'd also need to adjust the power so it remained constant with each barrel.

As you tried shorter and shorter barrels you would, in theory, find a point where you started to notice worse accuracy.

If an airsoft shop cares to allow me to borrow one of every kind of AEG barrel I'd be happy to put this to the test but I doubt they'd be up for it.

 

Basically, however, I suspect the M14 is a good gun simply cos it's got a good hop-up and it's design and construction is more modern so it's better built.

[Glenn]

Although I haven't used one, I hear M14s have a nicer hopup, meaning the hop BBs more consistantly and efficiently...begetting more range.

 

KSC Mk23 don't expel any gas when dry fired becuase their rocket valve is NC, or normally closed. The valve protrudes through the end of the loading nozzle, so when a BB is in the hop, the valve is open.

 

Consequently, the valve closes when the BB leaves the hop, so little gas is wasted. The gas present in the barrel continues to expand and accelerate the BB. This is why such a larg gun can be so efficient. My metal Mk23 gets more shots per fill than my metal TM hicapa.

 

A gun like the Hicapa uses the flow of gas to close the rocket valve, so gas is still leaving the barrel for as long as it takes the valve to close. Valve closing time is largely dependent on pressure.

 

Comparing the effects of barrel length on GBBs and AEGs is really apples to oranges...they don't work at all the same. AEGs generate BB velocity by creating a large amount of of high velocity volumetric flow...you squeeze all the air in the cylinder into the barrel, very quickly. Their is little compression of the air involved; this compression counts for very little energy. GBBs give up enthalpy (pressure and speed of a gas) through the expansion of prepresurized, saturated mixtures. A small amount of high pressure gas turns into a lot of low pressure gas, moving the BB and slide out of the way as it does so, until it can vent to atmosphere.

 

AEGs can be modeled as CV, or constant volume, systems, while GBBs are enthalpy engines.

[SilentSerpent]

There's a lot of people on here saying that the bb rolls along the top of the barrel due to the effect of the hop up, which makes sense until you think about the compressed air trying to force its way around the bb from behind. this air cushion will try to push its way around all sides of the bb as this would most effectively and evenly distribute (equalise) the pressure, which is what compressed air (or anything) always tries to do. so could someone come up with a calculation to back up the lift force on the bb outweighing the compression behind it? or will i just have to believe the 'pen on the barrel' results. the one thing that just makes me doubt this is that you don't even see the hop up take significant effect until about 20-30m downrange, so am i to assume that it slams itself upward into the barrel, then flies straight for a while, then lifts again? this seems unlikely. i'm not trying to start a physics debate here, i just trust maths more than people's 'proof' (again, nothing personal, but i have only the word of a stranger that the results are as stated).

 

SS

 

Edit: had a random quote there for some reason

[Stealthbomber]

The thing there is that there isn't anything forcing the air to move past the BB equally around its circumference.

In fact, air always takes the easiest path. If the hop causes the BB to flick up toward the top of the barrel then the air will just squeeze past the bottom wherever it can.

 

As for how hop-up works, I assume it's because, initially, the outright speed of the BB is enough to force it to go straight and then, as the velocity drops, that's when the spinning effect of the BB allows the hop-up to kick in and the BB lifts.

 

 

Just want to say that I don't mean to tell anybody that this IS what happens. Just that it all fits together, in my head at least.

[Glenn]

The thing there is that there isn't anything forcing the air to move past the BB equally around its circumference.

In fact, air always takes the easiest path. If the hop causes the BB to flick up toward the top of the barrel then the air will just squeeze past the bottom wherever it can.

 

As for how hop-up works, I assume it's because, initially, the outright speed of the BB is enough to force it to go straight and then, as the velocity drops, that's when the spinning effect of the BB allows the hop-up to kick in and the BB lifts.

Just want to say that I don't mean to tell anybody that this IS what happens. Just that it all fits together, in my head at least.

<{POST_SNAPBACK}>

 

 

Bingo. Air takes the path of least resistance, so if this is evenly around the BB, great, or if it is primarily underneath, that fine too. The air doesn't care, and has no inclination either way.

 

That doesn't mean the BB rolls on the top of the barrel, or that it bounces, its just a statement of fact.

 

I personally still side with the bounce theory, but it's only a theory, I don't know that anyone can provide any evidence either way. I do have a test plan, but I'm too busy at school to try it, if it would work at all.

[BCPneumatics]

Yeah I don't think that a rifled barrel would help if what we have read here is true.

 

1- two people have confirmed that the BB rolls allong the top of the barrel.  They proved this by marking the BB with pen.  This make sense with the back spin.  Therefore a rifled barrel would negate the HOP UP effect by forcing the BB to spin on access with the barrel.  Someone talked about the rifles creating an air cushion all around the BB but this seems unlikely.  Riffling should engage the projectile like with a minie ball.

 

2- a sphere like a BB wouldn't benefit from the aerodynamic benefit of spinning on axis with the barrel the way a bullet shaped object does.  Maybe if someone made American Football shaped BBs then a rifled barrel would make then fly farther but that's not the case.

I have a theory if I might throw it out there.  Maybe airsoft doesn't want a perfectly round barrel?  A trianglish shaped barrel might be more ideal?  And here is why...

 

If the BB rolls allong the top of the barrel and it is the lack of precision in the barrel that causes it to move slightly side to side, like a ball rolling down a gutter, as someone put it.  Would maybe a tirangle shaped barrel with the peak up keep the BB pushed up against the top with no side to side play.

 

Of course it couldn't be a true triangle because of all the air leakage around the barrel but maybe a slight taper up top to wedge the BB in a way.  Wish I new how to make something like that   Just an idea.

<{POST_SNAPBACK}>

 

 

this is along the lines of what I was thinking.. glad to see I'm no alone.

Also, I dont see how the rfiling would spin the BB a terrible amount at all, since the BB doesnt bite into it like a lead slug would.

(Also, semms that the blow-by would decrease velocity, though I don't know by how much.

[Sale]

A tight enough bore in a round barrel, a V-shaped notch in the hop packing (think KM hop packings), or a Big Out H-Hop piece are things that reduce the amount of side by side movement, since it's centered more precisely in the beginning.

 

One of the reasons the TM Hi-Capa is a very accurate pistol is the way they built the hop up. It presses the sides of the hop packing, rather than pressing the entire top part of the rubber.

 

-Sale

[Kellhound]

The explanation I read for "hop-twist" barrels had nothing to do with air flow, but with lessening BBs bouncing inside the barrel, making them slide along one groove (and losing some power due to that).

 

I put one in my stock P90 but only could check at 8m (inside home).

 

Not exactly a scientific test, but it looks slightly more precise:

 

 

I made the first series with standard barrel, then installed the Tanio Koba, adjusted the hop-up by eye and fired the second series.

The lower one is with "rifled" barrel. As you see, at 2 meters (red) there is no difference. This distance was for "warming-up".

 

At 8 meters, standard barrel went most to the right of point of aim, with one BB out of the target.

Rifled barrel results are one flyer (leftmost) and 2-in-1 hole.

Taking into account that I had not adjusted hop-up after swapping the barrels, not bad.

By mistake, i wrote 2M in the 8meter hits (blue) at second target.

 

I don't plan on changing anything else as I consider this a SMG and safety range rules around here (only some places) let me shoot almost point-blank at this power. Too many people are carrying pistols at powers to high for using at less than 8 meters

I'll have to wait for testing at longer ranges.

[GuzziHero]

Quick question then.

 

If I take a D-Boys M4, and cut the barrel to 110mm, will I significantly lose accuracy? Will this gun have a vented cylinder, and if not, would it advantage me to fit one?

 

Thanks

[angel_wings]

Another interesting point to raise.

 

If a GBB with a huge barrel gives a massive FPS boost (If being the most important word!!)

 

Then surely an AEG with a higher volume cylinder would also give an FPS boost.

 

So why doesn't it?

 

 

Note: I'm only interested, and am not claiming any of the above is true or false! (this thread seems to be raising arguments so i might as well stay neutral!)

[GuzziHero]

Another interesting point to raise.

 

If a GBB with a huge barrel gives a massive FPS boost (If being the most important word!!)

<{POST_SNAPBACK}>

 

Id guess because it doesnt have a piston to 'run out' of air before the BB is fired...all the gasses that would normally propel the BB still do so, but they have more time to expand. This is why the STTi Stealth Assassin (Mk23) fires at ~330fps but with the barrel extension fitted, it reaches over 400fps. Same reason why the 8" Digicon Target does ~420fps, the 20" does near 500.

[Tecro]

Really old topic, but new responses nonetheless...

 

I take it that GBBs use air that has "positive pressure" (meaning higher than atmospheric pressure of 15 PSI), while the pistons of AEGs use air with "neutral pressure." Suckback occurs for AEGs because at some point the BB's position in a long barrel the piston is all the way forward. The BB's forward momentum increases the volume, and the pressure (which was originally the same as in the atmosphere) drops--as in Boyle's Law. This "negative pressure" sucks the BB back.

 

The air that GBBs use to propel the BB is pressurized and significantly greater than that resisting the BB. Even if the airflow gets cut off at some point in a GBB, there will still be some high-pressure air inside the barrel. That air will continue to expand, and if it's at say 90 PSI, it can continue to increase the BB's velocity until the volume behind the BB is 1/6th of the cylinder--when the pressure equalizes. The FPS acceleration drops because the pressure drops, but because there's more momentum, there is still some positive acceleration. Friction is insignificant.

 

EDIT: Didn't see GuzziHero's post, but it's the same idea. BTW, you might not want to discuss a FPS over the forum limits...

 

EDIT again: Same with the post below.

[Aod]

Another interesting point to raise.

 

If a GBB with a huge barrel gives a massive FPS boost (If being the most important word!!)

 

Then surely an AEG with a higher volume cylinder would also give an FPS boost.

 

So why doesn't it?

the reason why gas guns with long barrels acheive such high FPS values if because the gas is constantly expanding throughout the barrel.

 

in an AEG, the air isn't compressed and as such, a longer inner barrel will not provide such (if any) a substantial FPS boost.

[Tecro]

Once again, same idea. Indeed, a longer barrel will create negative pressure and suckback.

[GuzziHero]

Epiphany!!! I just realised why there is a small oval hole in the right side of my M15a4CQB Compact SEAL...vented bloody cylinder!

 

Right...so if that is 200mm barrel length and needs a vent, so will the M4 when I cut it down. If it doesnt have a vent already, Ill have to cut one.

[Wedgie]

I understand that a rifled barrel wouldn't actually have that much of an affect of a bb. But in theory, the hop-up makes the bb spin backwards to slightly counteract the pull of gravity, allowing the bb to stay in flight for longer and be more accurate along its vertical plane. Where rifling makes bullet or pellet shaped projectiles spin around the imaginary axis of the centre of the barrel to give it better stability in flight by making it spin. So if the bb had backspin applied to it and was also spinning around that axis of the barrel, then the backspin would not be working in a vertical direction against gravity like its supposed to, but would instead be pulling in all directions as the original 'up' direction that it was spinning in is rotated.

I mean imagine if the bb was to rotate by just 180º while spinning backwards. The bb would then have front spin and the ball would go downwards. This is a hard thing to explain but i'm trying the best i can. Also, as i said before, this is working more on the theory of each, as i know that rifling would not have such a significant affect on an bb as it would on a bullet or pellet.

[gunfighters]

ok lets see if my "theroys" on things is in line with every one else here.

 

1 most of us play with in some sort of FPS limits 2 guns shooting 1 joule will have the same range regardless of the leinth of the barrel ( assuming all else is =) . it not that hard to make almost ANY AEG shoot @ our limits(US or UK)

 

2 accuary is a funtion of barrel quality (and hop etc) not how long it is(with in reastion, just stop with the UMFG MP5K sniper rifle), this has been proven in RS, olympic air guns, and Sid's work with AS.

 

3 a vented clinder causes the bb to accerate faster . more importanly it causes the BB to cross the hop up bucking faster, giving more RPS @ given seting then the same set up with an unvented clinder.

 

4 A hever BB will give more range asuming you can put enuf hop on it

 

5 the longer the barrel the more it slows the back spin due to friction(efect may be negabul)

 

6 the longer is better myth mainly stems form the site radius, longer raidus makes it easer to aim, making the shooter more accurate, not the gun. modern opticts (and the ranges of AS) negate this

 

so if we put it all together, you should get BETTER range and accuarcy out of a midsized barrel and vented clinder do to the fact it will alow you to more eficantly shoot hever ammo.

not saying we should play with sawed off aegs or shorten out inner barrels. just it seems that adding a longer barrel and hideing it in a supressor is more about looks then performance, and the longer less agile gun is a hinderance

 

as for barrel suck and negtive pressuer... dosent realy happen that way. put your hand in frount of you gun and shoot it (empty), feel the air?, thats proof of postive pressuer.

what happens is as soon as the piston head slams home the bb is moving as fast as it will go, if its still in the barrel @ this point it will start to slow down do to the friction of the barrel

why are people hung up on rifling a BB? wellits "seams: like the right thing to do. as you could put a spin on the bb that would have it climbing into the sky if it was hop up. but with out lift the "bore site" of the gun whould have to be so far over the target it makes using sites useless.

Hop up does the same thing it spins it around the acess and provides lift as a benfit.

[angel_wings]

Another interesting point to raise.

 

If a GBB with a huge barrel gives a massive FPS boost (If being the most important word!!)

 

Then surely an AEG with a higher volume cylinder would also give an FPS boost.

 

So why doesn't it?

the reason why gas guns with long barrels acheive such high FPS values if because the gas is constantly expanding throughout the barrel.

 

in an AEG, the air isn't compressed and as such, a longer inner barrel will not provide such (if any) a substantial FPS boost.

<{POST_SNAPBACK}>

 

not quite sure if you follow my point.

 

AEG1 has a short inner barrel with the correct cylinder equipped

AEG2 has the same inner barrel but with a LARGER cylinder.

 

So why does AEG2 shoot at a lower fps????

[Sale]

Angel wings: Because the correct cylinder allows the piston to accelerate before shoving the BB into motion.

 

-Sale

[Hedganian]

Is there possibility that a tightbore barrel with a 1J spring would actually push the gun over the UK limit in FPS?

<{POST_SNAPBACK}>

 

Okay here are some FACTS, as taken from Spectre Wargames' official site Chronograph at the time.

 

I had my AUG tuned to 330fps (on the nose, 8 shots out of 10), with a full gearbox upgrade, pistol, spring, bushings, the works. Chrono'd reliably at 330 fps nearly every trigger pull. With full auto it dropped off slightly, something to do with piston travel, I think. But that's not relevant. It has a standard-lrngth (509mm) TN 6.04 inner barrel.

 

I installed the Boom Arms H-Bar conversion kit to a spare barrel, and fitted it with the Prometheus PSG1+ 6.04mm brass tightbore inner barrel. It is for the extended PSG1 and it's 650mm long. It's LONG! Using the same gearbox it chrono'd reliably at 360 fps, on the same chrono on the same day, with the same ammo, etc, etc, etc.

 

This is as close to a scientific test as I've done. The extra barrel length added 10% onto the fps, with all other factors being the same. I didn't group and zero with it verus the standard barrel, but I'm going to assume that the group would have been tighter with the longer barrel, based on the concept of lower travel time = less opportunity for deviation.

 

This conclusion is further upheld by the results of chrono'ing the shorter barrels I have now got for the AUG. (I love my AUG and its many barrels ) The shorter barrels give a lower fps than the standard barrel, which is good because I use them in CQB where I don't want or need monster fps. (No, shooting people at 2m range with a full-auto burst from a 330fps weapon is NOT funny )

 

Just remember that the 1J limit applies to the muzzle energy, NOT to the spring or whatever. If you put a M100 spring in your AEG, you MAY be firing over 1J at the barrel, but you MAY not, due to other factors. Likewise, the H-Bar barrel on the AUG was firing OVER 1J because the gearbox, etc had been tuned for a shorter length of barrel to produce 330fps at the muzzle (or near enough).

 

Luckily, it's inside the 10% deviation most sites allow, so I can still use it. However, being a sensible airsofter, I use it only for longer-range shooting and as a support weapon. That's what it's for, that's what it is, that's how I use it. You won't see me doing room-clearance with the H-Bar (not if I have a choice, anyway). That's why I have multiple barrels, to tailor my rifle to my needs without having to buy a million different AEGs (although that might have been cheaper and easier, but not as much fun. )

[Tecro]

I mean imagine if the bb was to rotate by just 180º while spinning backwards. The bb would then have front spin and the ball would go downwards. This is a hard thing to explain but i'm trying the best i can. Also' date=' as i said before, this is working more on the theory of each, as i know that rifling would not have such a significant affect on an bb as it would on a bullet or pellet.[/quote']

That's why we don't use rifling for Airsoft, except for that one barrel that only worked for less than 50 feet or something. The reason the BB doesn't roll 180 degrees is that there's gyroscopic action. The rotation resists movement of the axis.

 

2 accuary is a funtion of barrel quality (and hop etc) not how long it is(with in reastion' date=' just stop with the UMFG MP5K sniper rifle), this has been proven in RS, olympic air guns, and Sid's work with AS.[/quote']

I wouldn't jump to that conclusion. The function of deviation of the BB vs. barrel length is likely fit by a log. A longer barrel will help, just not much once the barrel is already long.

 

3 a vented clinder causes the bb to accerate faster . more importanly it causes the BB to cross the hop up bucking faster' date=' giving more RPS @ given seting then the same set up with an unvented clinder.[/quote']

That's another unjustified conclusion. You have to factor in the barrel length. On a shorter barrel, the last bit of motion for the piston is wasted because the volume displaced earlier was used instead. The BB would be out of the barrel. However, a longer barrel uses the full motion of the piston, and all the displaced air is used. Correct, the BB moves slower past the hopup, but its final speed is greater.

 

4 A hever BB will give more range asuming you can put enuf hop on it

Never heard of this. It can provide greater effective range as the accuracy stays high for longer, but the overall range is slightly shorter.

 

5 the longer the barrel the more it slows the back spin due to friction(efect may be negabul)

That should be negligible. The continuing displacement of the air vs. possible negative pressure are dominant.

 

6 the longer is better myth mainly stems form the site radius' date=' longer raidus makes it easer to aim, making the shooter more accurate, not the gun. modern opticts (and the ranges of AS) negate this[/quote']

It's no myth; the reason longer barrels aren't used are because of other factors like clumsiness, suckback unless you de-vent the piston, etc. A longer barrel both increases the BB's speed (with a de-vented piston, as there's more time for the BB to accelerate) and accuracy (as the barrel absorbs the sideways vector of the velocity and makes the path straighter). That said, you can't always use the extra velocity/accuracy (CQB) and a 650 mm barrel can be bad (CQB).

 

so if we put it all together' date=' you should get BETTER range and accuarcy out of a midsized barrel and vented clinder do to the fact it will alow you to more eficantly shoot hever ammo.[/quote']

Wrong. If anything, using a longer barrel makes use of the energy expelled to move the piston the whole length, as opposed to using only part of its movement to propel the BB.

 

not saying we should play with sawed off aegs or shorten out inner barrels. just it seems that adding a longer barrel and hideing it in a supressor is more about looks then performance' date=' and the longer less agile gun is a hinderance[/quote']

True, that length can be a hindrance in some cases, exceptions being for sniper rifles or bullpups.

 

as for barrel suck and negtive pressuer... dosent realy happen that way. put your hand in frount of you gun and shoot it (empty)' date=' feel the air?, thats proof of postive pressuer.[/quote']

No, it isn't. Think about it in terms of air displacement. True, the BB's inertia momentarily pressurizes the air as it doesn't move quickly at first, but amount of air displaced inside the cylinder equals the amount of air used inside the barrel. Or it should.

 

You feel the air because that's the jet of air pushed out of the gun. There will be a bit of extra pressure due to fluid air resistance, but it gets equalized. Similarly, the momentum of the BB keeps it going even when the flow of air from a vented cylinder stops. That increases the volume and decreases the pressure to below 15 PSI.

 

what happens is as soon as the piston head slams home the bb is moving as fast as it will go' date=' if its still in the barrel @ this point it will start to slow down do to the friction of the barrel[/quote']

Once again, the barrel friction is negligible. As I said, the negative pressure is far dominant over the friction, although both do contribute to slowing down the BB. If the friction was high, why won't a long barrel + unvented cylinder get low FPS?

 

AEG1 has a short inner barrel with the correct cylinder equipped

AEG2 has the same inner barrel but with a LARGER cylinder.

 

So why does AEG2 shoot at a lower fps????

Because of the unvented cylinder. On the first AEG, the unused movement of the piston is before it starts to push the BB. On the second gun, that extra movement occurs after the BB has left the barrel. And as others have said, momentum makes the piston go faster in the last part of its cycle. So it moves faster in AEG1.

 

Angel wings: Because the correct cylinder allows the piston to accelerate before shoving the BB into motion.

Like that.

 

EDIT: Argh...lame quote problems. Hopefully it isn't all too confusing.

[gunfighters]

"Wrong. If anything, using a longer barrel makes use of the energy expelled to move the piston the whole length, as opposed to using only part of its movement to propel the BB."

your missing the point entirely...

YES a longer barrel can give you more FPS and thus more range... but we have LIMITS and geting a mid sized barrel to shoot up to those limts is no problem with proper tuning.. FPS is not a factor as I stated we are talking about 2 hypetical guns tuned to shoot @ a given limit

 

"That's another unjustified conclusion. You have to factor in the barrel length. On a shorter barrel, the last bit of motion for the piston is wasted because the volume displaced earlier was used instead. The BB would be out of the barrel. However, a longer barrel uses the full motion of the piston, and all the displaced air is used. Correct, the BB moves slower past the hopup, but its final speed is greater."

no you just conditered your self, we are talking about speed pased the hop up bucking and you just agreed to that in you last line

 

"I wouldn't jump to that conclusion. The function of deviation of the BB vs. barrel length is likely fit by a log. A longer barrel will help, just not much once the barrel is already long."

no juming to anthing, plenty of facts to back that up

realsteel (refance only as it is related)

http://www.accuratereloading.com/223sb.html

http://www.findarticles.com/p/articles/mi_..._110470564/pg_1

http://www.tacticaloperations.com/SWATbarrel/

 

airguns(refance only as it is related)

http://www.pyramydair.com/blog/2005/04/is-...-important.html

http://www.pilkguns.com/aphp/comphis.htm

"In the early 1980s an American shooter, Don Nygord, found that shortening the barrel length greatly improved the balance and inertial envelope of the gun, and this reduction in length did not adversely effect velocity or accuracy. Nygord used his shortened version of the M65 to win the World Championship at Santo Domingo in 1981"

 

airsoft-scroll down to the 9th post, testing a bunch of diffrent sizes on the same gun

http://www.arniesairsoft.co.uk/forums/inde...try630707"

paint ball(refance only as it is related)

http://paintball.about.com/od/paintballbarrels/f/blength.htm

http://www.automags.org/resource/tech/toms...arrel_eff.shtml

http://www.paintballtimes.com/Article.asp?ID=305

 

"4 A hever BB will give more range asuming you can put enuf hop on it"

"Never heard of this. It can provide greater effective range as the accuracy stays high for longer, but the overall range is slightly shorter."

 

right... thats why we see snipers shooting .12 bbs.

over all range is greater(asuming you can give it enuf hop up) and in fact the hever BB even tho it starts slower with be moving FASTER then a point 2 @ about 80'. its a drag vs mas thing. drag increases with speed, the faster a bb goes the more dragforce is aplyed to it and the faster it slows down. if 2 pojetiles of teh same size and shape start with the same amout of engery and one flys slower, the slower one has less drag and thus flys farther

http://arniesairsoft.co.uk/?filnavn=/artic...s_dist_time.htm

(mods, sory I don't have a 1j graph, it looks the same only the ranges are about 25' shorter so I posted that grafh I had as a refrance for what a bb does in flight, regardless of its starting engery)

looking @ the graph you will better the range of you gun by shooting the hevest BB the hop will handel. the graph shows what can happen, but most guns hop up won't handel .43s with in given limits, and thus the bb will drop off.

 

"And accuracy (as the barrel absorbs the sideways vector of the velocity and makes the path straighter). "

again wrong, the "absorbing" of any "sideways vetor" whould cause friction on said side of bb causing a slight spin in that direction and having the bb hook or slice.

accucry is not some weired funtion of the barrel forcing the bb in to a strate line, its about the barrel and system doing the SAME THING every time

given a 6.01 TB barrel and a way to tune them to shoot the same FPS you will see little change in performace between a 1' barrel and a 3' barrel.