HPA is it over powered?

[Airsoft-Ed]

The principles at work aren't complicated, it's how they all work together and the sheer number of variables that make it an uncertain thing.

Hop is just a brake that only acts on one side of the BB. More hop = more brake, so the bottom of the BB goes faster relative to the top, so you get more spin.

Then obviously more spin causes shots to go up, less causes them to go down. That's the work of the Magnus effect.

Heavier BBs can be spun faster without it causing them to climb upwards because of their weight, so they maintain their spin longer, as well as their velocity due to it taking more air resistance to slow them down, and so they reach out further, and carry their energy better.

The one thing that I REALLY want to get my hands dirty and test properly, is whether or not widebores are actually better for accuracy at range. Because in my head, that entire concept makes absolutely no sense whatsoever.

 

[PT247]

will be testing my WBB this weekend, had a TBB in previously, both are Prometheus

 

[Colonel Kurtz]

The principles at work aren't complicated, it's how they all work together and the sheer number of variables that make it an uncertain thing.

Yeah and that's the stalemate of being unable to determine this precisely without a lab my friends got to.

It all got abit hard fow me to follow, but they gave me enough school-kid summary to gather the following in relation to barrel bore, please forgive me if my memory has failed and i get anything jumbled or miss any key relational points;

They said that the spin of the BB would create a layer of pressure/air around it, and that this can reduce the effects of the surrounding air/environment on the bb as its deflected by it. They said there's an optimum for spin (depending on the size/mass of the BB and force applied) and too much spin/instability can create an effect 'i forget the name' where this pocket of air/pressure around the object isn't stable, and vents pressure/air in one direction, pushing the object away in the opposite direction.

They agreed that the stability of this pocket of air/pressure around the BB is the main factor in accuracy. That relational to amount of spin applied by the collision with the hop-up, there would be an optimum bore for a barrel that would allow this layer of vacum/air to form better, and that there was another optimum in terms of this pocket itself that would reduce the amount it is effected the moment it leaves the barrel.

They said that assuming the BB was always the same dimensions/mass, that these 'optimums' would differ depending on the volume of air being used to push the BB and the force/speed it travells at, the volume of the barrel, the temperature and the amount of air-pressure at the beginning and end of the barrel.

They seemed to think this would be very easy to calculate in a lab and considering that theres only about a dozen diff barrel lengths commonly used they were suprised no-one had done so already. They said therefore there's no universal principal of one barrel bore being 'better' or 'worse' for accuracy, but it'd be easy to define a vague optimum (they consider the increments of availible barrel bores being 0.01mm very vague when using a 6mm projectile) for different combinations of cylinder and barrel volume, that that a precise amount of hop-up to set could then be calculated.

They said for HPA or gas, it'd be much harder to define as they doubt the volume of spread of pressure in the air/gas released for each shot is anywhere near consistent enough, and went as far to say it might be too inconsitent for the bore to make a tangeable difference in this manner. They also said it's possible that an AEG could have a similar amount of inconsistency due to build quality to also make it largely irrelevant, that the amount of consistency required for the bore to matter to accuracy at all could end up being something of an aerospace/F1 build standard that isn't seen in airsoft at all.

TLDR: It's possible to calculate exact optimum bore, but differs depending on cyclinder/air volume/force applied and initial unadjusted barrel volume (assuming 6mm for 6mm projectile). That it's also likely these are inconsistent enough due to build-quality of airsoft guns not being aerospace/F1 standard for barrel bore to make no tangeable positive or negative difference. (unless an extreme like 6.5mm or 6.00000000001mm for 6mm projectile etc)

 

[Airsoft-Ed]

They said for HPA or gas, it'd be much harder to define as they doubt the volume of air/gas released for each shot is anywhere near consistent enough, and went as far to say it might be too inconsitent for the bore to make a tangeable difference in this manner.

HPA is exceptionally consistent, that's why people are moving over to it. It allows you to apply more air than could fit in a cylinder, and it allows it to be more precisely applied than it can be from a cylinder by a piston.

Though gas is by its nature ridiculously inconsistent as it is temperature dependent, and using it lowers its temperature. The only reason gas rifles have anything like consistent shot placement is because they fire so much more gas down the barrel than they actually need to, that a shot has ample to use what it needs, so the shot weight creates it's own consistency in a way, by just making use of an effectively endless supply. If that makes sense?

Of the volume of gas sent down the barrel, a .2 probably only uses about 20% of it, if that. The fact that there's still 80% helps with the consistency because how much gas gets applied to the shot depends more or less solely on its weight.

Heavier shots will simply use a higher percentage of the gas supplied down the barrel.

You'd probably need the barrel to be 2m long, or to use BBs weighing in excess of 1g before you got to the point where the gas supply fell short of the barrel volume.

But yeah, back to the whole "cushion of air" thing. I just don't buy it. It's like heaven... It sounds nice, but frankly, it's too good to be true. So by the same token, I'll believe it when I see it, and not before.

If a barrel is wider, the BB can more easily ricochet down it instead of flying straight, because there's more space for it to bounce around.

If a barrel is narrower, then it'll get sent straighter.

That just makes more sense to me, and based on the fact that tightbores are more accurate than not-tightbores, it just stands to reason that it's true.

So how can a barrel that's wider than a standard one be more accurate? There is just no logic there that I can see at all.

 

[M_P]

If a barrel is wider, the BB can more easily ricochet down it instead of flying straight, because there's more space for it to bounce around.

If a barrel is narrower, then it'll get sent straighter.

To be fair in the same breadth you could say a thinner one means more bounces in a quicker space of time. I think with several inner barrel manufacturers making wider barrels there has to be something in it. Why bother if not? Add to that the large amount of people switching to orga barrels and others and having good results there's clearly some benefit. It's likely both achieve a similar outcome through different means if anything, neither is likely to be hugely worse or else so many people wouldn't use them.

With simple logic tighter is better but i dont understand why you can't believe in the air cushion proposal, it's more than plausible, it's not like a bb holds much mass . just depends which theory you subscribe to but I highly doubt people who've spent significant amounts of money on high end stuff like ptws and p*'s run wide bores over others for no reason.

Or it could all make no difference and it's literally just the quality of the components that make the difference :lol:

 

[Lozart]

 

[Colonel Kurtz]

From what you've said it sounds like the 'consistency' you're describing is just using a surplus of air so there is 'consistently' always enough air, not consistenly the same volume of air released each time, which was what they were talking about.

I dont know enough about HPA, but assuming the volume of air released with each shot is actually more precise/consistent each compared to an AEG, the main factor my nerd-friends considered the instability was the spread of pressure within the air, caused by the air quickly changing between different pressures as it goes from tank to tube to out the nozzle.

The 'cushion of air' in the barrel around the BB would effect how it's coating of air/pressure is formed and the amount of it, and that's the whole point in barrel bore making any kind of difference. The idea that the cushion can be made larger and therefore better by a significantly wider bore is a fantasy, as there will be more room for inconsistency in the pressure along this cushion, which would have the opposite effect, or at least counter act any posistive effect.

In terms of 'bouncing around' in the barrel, my friends said that regardless of how much space to bounce around the BB has, that if it is significantly trying to bounce-around then an airsoft gun simply isn't precision enough for the barrel bore to matter, unless a total extreme then ofc it'll be much worse, and that as long as the barrel bore was wide enough for it not to get stuck due to being not precisely spherical, it doesn't matter.

At this point i gave up and got another beer, and will do so again now

But the lasting impression i got from the whole evenings debate was; that airsoft guns simply aren't precision enough tools to worry about any of this shite, and it's just a tinkering/pimp-my-riding indulgence that we all try to justify. That when youre just trying to hit a person with a 6mm ball of plastic within the same range you could chuck a rock at them, it doesn't matter. That alot of things that supposedly make a difference is just that 90% of people wont buy an 'upgrade' for something and then tell people it made no difference, the mind will invent one.

 

[Colonel Kurtz]

That's pretty much how i looked when getting this lecture from my mates, only perhaps eyes slightly more closed/red

 

[Lozart]

Once the BB leaves the end of the barrel the spin creates lift. That lift will be reduced if the turbulence generated by the spin becomes too great which can easily be exacerbated by surface imperfections in the BB interfering with the laminar layer of air surrounding the BB. To me at least it seems there would be far greater impact on range and consistent shot grouping from external forces acting on the BB and from the surface of the BB itself for this very reason.

 

[Colonel Kurtz]

Once the BB leaves the end of the barrel the spin creates lift. That lift will be reduced if the turbulence generated by the spin becomes too great which can easily be exacerbated by surface imperfections in the BB interfering with the laminar layer of air surrounding the BB. To me at least it seems there would be far greater impact on range and consistent shot grouping from external forces acting on the BB and from the surface of the BB itself for this very reason.

I look forward/hope to get to play airsoft in space, then we'll all def need HPA!!!

 

[Lozart]

I look forward/hope to get to play airsoft in space, then we'll all def need HPA!!!

Ah but you wouldn't though. In a vacuum there's no air resistance to slow the BB down. Your shots would basically carry on infinitely until they end up in the heart of a star or pinging off a comet. Or tearing a hole through a multi-million dollar satellite.

 

[Airsoft-Ed]

Wouldn't need hop or anything!

AAAAALLLLLLLLL OF THE RANGE.

 

[M_P]

Or tearing a hole through a multi-million dollar satellite.

Or another person

 

[Airsoft-Ed]

Only if they were made of cardboard or something.

 

[Lozart]

Or another person

Not enough mass. You'd achieve 340FPS (or whatever) and that would remain constant. To be fair the only reason it would damage satellites is because they have a habit of orbiting at ludicrous speeds so the closing velocity would be high. If you went up on the space shuttle (or some dodgy as fuck piece of repurposed Soviet crap) and shot at your mates with your P* then you'd be travelling at the same relative velocity so you'd just hit them with a 340FPS BB.

 

[BrightCandle]

Hunterseeker 5 did an experiment to try and determine if the orga barrel was good because it was precision engineered, wide bore or actually because it has a long secondary crown. He did this experiement by making a bit that can be used to widen the end of a barrel in much the same way the orga barrels do, and you can get the other elements in other barrels. The end result of this experiment was the tapering works to improve accuracy on all types of barrels (wide bore and tight bore). Its simply more accurate to flare the barrel out a little bit at the end. Orga has no better precision engineering than any other company out there. Whether tight verses wide is measurably different I don't know, mainly because the two don't really apply to the same gun so we never see all else being equal. But the orga flare is definitely worth having and you can pick up the parts to do it from Hunter seeker armouries or go ask air-lab to import it like I did with the lapping kit.

 

[Qlimax]

I run an HPA weapon and i think they are completely fair. Mine is doing 330Fps although I could easily crank it up to 350Fps with that being consistent ever shot but i don't plus I also use a speed trigger which mean I can fire as many as i can in semi but looking at the performance of firing it in semi for as fast as my finger can move then it fires just like a PTW. the trigger response on those are good as good if not better without any mods to the trigger.

now i think they hurt more as most HPA users use a heavier BB, mine is doing 330 on .20s but use .28s and if you use the right setup with your barrel, bucking and hop then they can be really good both accuracy and range.

I also have a fully converted GBBR to HPA not the tapped mag thing this one is internally converted and that's fair game as well.

 

[jcheeseright]

I think people whining about HPA guns hurting more or whatever are either being fannies (highly likely) or they're buyin into what they've been told which is that HPA guns hurt more and so their brains are telling them it hurt more.

Once a BB leaves the barrel it doesn't make a jot of difference what propelled it, if it's got 1j of energy at the muzzle it could be fired by a rail gun and it'll still hurt the same amount as one from an AEG. The only reason HPA is becoming more popular is consistency, when you can guarantee that ALL of your shots will be within a 2fps margin you can get great 'accuracy' (I've said before there's no such thing as an accurate airsoft gun, only consistent ones) from your gun.

Joule creep notwithstanding, there's no difference in the ballistics of a BB from an HPA gun to that of an AEG.

NONE.