Fps raise. Let's get it DONE

[toothpick-NL]

a ateammate of us spent like €500,- on upgrade parts but he is shooting were he is aiming.

its pretty scary if you see what he can hit with his bolt. but luckely he's on my team

[Ian_Gere]

Joule Creep, like Suckback, is a theory which makes complete sense when explained generally, but in actual fact, once the maths are applied it starts to look a bit different.

 

100m/s = 328fps = 1J w/ 0.2g BB

81.62544m/s = 267.8fps w/ 0.3g BB = 1J also

455mm barrel = 0.45m / 100m/s = 0.0045s time of a 0.2g BB in the barrel

455mm barrel = 0.45m / 81.62544m/s = 0.0055129898291463s time of a 0.3g BB in the barrel

Difference = 0.0010129898291463s

A 0.3g BB spends approx 1 millisecond longer than a 0.2g BB in an AK barrel

Now I'm not familiar with the maths which describe how much energy is transmitted by expanding air but I do know that, just like sound, it is exponential. So if the force at arbitrary distance A from the point of origin is X, at distance 2A the force is the square root of X. But also the speed of the BB actually starts at 0m/s so what we really need is to know how to calculate the acceleration which the force imparts... engineers? We are talking about what happens at the very end of the time in the barrel though and we do know the final velocity, so I think we can make educated guesses at what is happening just before the point in time at which the velocity is measured accurately enough for this discussion.

But leaving that aside, instead lets consider 0.2g BB's in an M4

(363mm barrel = 0.36m / 100m/s = 0.0036s) ^(455mm barrel = 0.45m / 100m/s = 0.0045s)

Difference = 0.0009

If you put the same cylinder and spring in an M4 that you put in an AK, do you expect to see a difference in performance that translates into a usable advantage in play? No. And that is an approximately equal time difference as that caused by the difference in weights.

Ipso facto it's bollocks.

---

Yeah good hop... bla bla bla... Consider this:

Assuming the site has the common limit of 350FPS

Gun 1 has hop unit & rubber A and spring X - it fires @315FPS and gets a 0.6m grouping at 50m

Gun 2 has hop unit & rubber B and spring Y - it fires @345FPS and gets a 0.6m grouping at 50m

Gun 3 is yours to build. You can choose either hop and either spring. Do you choose A & Y or are you mental?

[Unrustle_Thine_Jimmies]

I've dug up some threads on airsoft mechanics,which is probably the best place for airsoft physics + technical stuff to explain joule creep in a bit higher detail. I recommend to read them fully.

http://forums.airsoftmechanics.com/index.php?topic=11308.msg133390#msg133390

http://forums.airsoftmechanics.com/index.php?topic=11161.0

 

It's hard to use maths to calculate joule creep as there are so many factors,as pistons don't expel the air volume in the cylinder instantly. Calculating gradual expanding air and how it affects a load accelerating down a cylinder which also has blow by depending on the bore is also hard enough,don't forget to factor in compression quality and compression rate and all that stuff.

 

Using the old fashioned method of jamming in different parts,tuning them appropriately and testing to see which set gives the best results is probably the best method of finding out how joule creepy your gun is.

 

Here's a post by hunterseeker5,a guy generally regarded to be pretty experienced in matters like this:

 

--------------------------------------

 

Lawlz r/airsoft. What will they think of next?

________________________________________________________________________

Quote from: AcidReaper on 26-11-2013, 03:06:43

This is a direct quote from one of the comments on reddit.

"It may be generally known but it's dead wrong. Experimental results show just the opposite. This guy in the linked article shot himself in the arm at point blank range with .12g, .20g, .25g and .28g BBs from the same gun, with the same spring. The .12g BB did the most damage. The pictures speak for themselves.

Joule creep is nothing but a chairsofter's pipe dream apparently. Real world BB wounds on bare flesh are not a pure function of Joules. There is something more complex involved."

http://www.nationalairsoftmagazine.com/ouch.html

Is there any suggestions on a better way to explain it?

_______________________________________________________________________

What are we arguing here exactly? Because I'm seeing separate issues: tissue damage vs. KE shift.

Regarding tissue damage, the point of that article was to show bbs with effectively identical kinetic energies impacting skin. Its demonstrating that, all else being equal, its velocity that does the superficial tissue damage. This is because BBs don't have much energy, even our insane high power guns have very little energy, so the higher velocity the round the higher the impulse force on just that top layer of skin and thus it destroys more capillaries and appears to be a worse wound. Thats that theory. There are three problems invoking it in this argument though: 1) all the rounds are intended to have roughly the same kinetic energy, 2) as you can see from sites like the ATP, higher mass rounds retain their kinetic energy better, and eventually not only overtake their higher muzzle velocity lower mass counterparts, they end up with a higher velocity than them as well (ref. http://mackila.com/airsoft/ATP/07-b-01.htm), and 3) I don't think anyone is trying to make the point that the reason they want joule creep, as its come to be known, is to @#*! people's #%$! up at point blank range.

So in regards to actual KE increases, I should start by saying not all guns display it to any significant degree. In fact, unless you specifically tuned for it, its existence is an indication you likely screwed something up with your build because it has negative effects on accuracy as a result of muzzle turbulence. Achieving it in an AEG is relatively simple, drop a 200mm barrel in your gun and a full cylinder. Tada, unless you're at fringe high power levels, your gun will see increased power with higher mass ammo. It only really came into the public eye as of late though because with P*s its so easy to inadvertently do, more and more people started "discovering" it for themselves. The point of doing it, intentionally, isn't to @#*! people up, its to gain an advantage; this is the same with all tuning. If you can be field legal (400fps with .2s) why wouldn't you take a 20% power gain with your preferred .3s? You're still field legal, and now you have a serious range advantage.

In regards to field rules to adapt to this: field restrictions are by the Joule, end of story. Your gun with your ammo must be X Joules (usually 1.5 for most fields) Of course this would require the chrono monkeys to have two brain cells to rub together, something which might be a bit of a stretch unfortunately, but otherwise you're stuck with things the way they are. Alternately you could run some experiments to determine maximum likely KE creep, and adjust the limit with .2s downward so that what you consider to be "safe" is within the limits techs running over-volumed guns will be able to achieve with their ammo. That way it preserves our advantage as the superior species, while keeping everyone "safe."

[CaptainSwoop]

I call bollocks on 'Joule Creep' being a factor in range. We are talking about fractions of a gram.

Seems to me it's as much psychological as anything, you aren't adding any more energy.

[Unrustle_Thine_Jimmies]

When I say range,I mean effective range,as in range you can actually use. Effective range is a combination of how far your gun can fling the BB and how accurate it is. Your BB may fly a long distance but have an uneven trajectory. it may fly a long distance but it may curve off back to Japan to the injection molding machine it came from.

 

Heavier BBs retain kinetic energy better than lighter BBs. Heavier weights are more resistant to wind and are more stable. Kinetic energy is also a factor on BB flight.

 

Joule creep exists,there's no denying that. How effective it is really varies on how well your gun is tuned,and it's traits(Cylinder to barrel volume ratio,all that craic)

 

Second post in this thread shows chrono results between .2g BBs and .4g BBs.

http://www.airsoftsniperforum.com/32-general-sniper-talk/9995-energy-creep.html

 

also check this out too,the airsoft trajectory project,Section VII shows how heavier bbs,with a greater Kinetic energy fly compared to lighter weights.

http://mackila.com/airsoft/atp/

[CaptainSwoop]

We are still only talking about fractions of a gram though

[Ian_Gere]

Well Alex, I commend your diligence, but I can't read those Airsoft Mechanic links because I'm not a member, but then again, as I said at the top of my previous, Joule Creep does make perfect sense when explained generally. You're also right that the maths involved is extremely complex, not just describing expanding air mass X in volume Y exerts force Z, but as you say the air is not sealed behind the BB, but also there will be a slightly different friction coefficient between barrel and various makes of BB, although how fast the air exits the cylinder does not actually matter because, according to Pascal, the system, ie cylinder, nozzle & barrel, has to be treated as a single volume against which the compressed air presses with equal force all over its inner surface. But also consider that the higher the pressure inside the system, the worse the leakage will be.

 

For anyone else following this discussion, in terms of physics the correct way to understand the issue is that once the piston is released the volume of the system changes at a different rate for different weights of BB, so the internal pressure at any given moment is also different, and because the system will eventually only contain between approx 2/3rds and 1/2 of the mass of air (depending on cylinder/barrel ratio and leakage), that air will continue expanding until the BB has left the muzzle. Hence we are attempting to determine whether the fact that, at any given moment of time after the piston is released, while either BB is still in the barrel, say 1ms, the slower moving one will probably be under slightly more pressure, since the volume behind it is less but the mass of air approximately equal (not equal since the higher pressure volume leaks more), actually results in a noticeable shooting advantage or whether it is just, to nerds like me, an interesting phenomenon which translates into bugger all irl.

 

To put the subject to bed once and for all we would need the results of a statistically significant number of experiments where both the instants of piston release and of muzzle exit were recorded alongside spring strength, muzzle velocity, and barrel length, so we could work out an accurate average acceleration of fired BB's (why not just record the BB weight and distance of trajectory as well? Because ballistics is even more complex than ordinary fluid dynamics, so, in the absence of actually measuring the strike force of thousands of different BB weights fired from hundreds of different guns, we need a figure which is applicable to real world situations as well as lab conditions). From that we could work out fairly accurately the volume and hence pressure / time and thus the total amount of energy transmitted using calculus.

 

My position however is that we can cut through the most difficult maths and that, without reliable explanation by someone/s who do fully understand all this, the complexity of the subject actually does nothing to aid our understanding, in fact exactly the opposite, because since we must admit that we do not know the ins and outs of a duck's arse about the subject, we are being asked to accept that we do not know enough to make a useful real world estimate, which, I submit, is not the case. My above quick and dirty calculations do not take acceleration into account so the difference in times spent in barrel by different BB weights cannot be relied upon as an absolute figure, but we can say that since the BB starts at rest and reaches the muzzle doing, say, 328FPS, then if we did have an acceleration figure to work with we would discover that it takes longer for the BB to travel, say 455mm, than simply dividing that distance by the velocity, 100m/s, and coming up with 0.0045s.

 

We know that the biggest single variable is the BB weight and everything else remains approximately the same, so the crucial understanding is to realise that whatever the actual figures are, the ratio between the unknown real times in barrel for 0.2g and 0.3g BB's will be the same as in the Q&D calculations, since we are working with known velocities, i.e.

 

0.0045s (the time taken for a 0.2g BB to travel 455mm at 100m/s)

/

0.0055129898291463s (the time taken for a 0.3g BB to travel 455mm at 81.62544m/s)

 

= 0.816 (3dp)

 

So whatever the real times are, the 0.2g one will be approx 81.6% of the 0.3g one.

 

What matters for the estimate though is the ratio of the difference between whatever the real times are in ms and those times themselves, which we know will not differ by more than 20%, and we also know must be greater than my Q&D results, so...

 

≤0.0010129898291463s / >0.0055129898291463s = <0.1837459999999971

 

...or, in plain English, what we are talking about is the energy which can be transmitted in less than the last 18% of the total time in the barrel, bearing in mind that during this time the force transmitting the energy is exponentially less than during the previous 80-odd% of the time.

 

Thing is, all of that goes on kind of subconsciously... as I said above, you only need to consider the difference between barrel lengths. Yeah, there is a difference, but it isn't significant enough to affect play.

[M_P]

We are still only talking about fractions of a gram though

to be honest that's not a great argument against it. A .3 is much more accurate than a .2 and still a fraction of a gram, little things do make big differences.

[Ian_Gere]

to be honest that's not a great argument against it. A .3 is much more accurate than a .2 and still a fraction of a gram, little things do make big differences.

yeah, it's not fractions of weight we need to look at, it's fractions of time, fractions of milliseconds even...

[CaptainSwoop]

Has anyone actually done any controlled testing of different weights? a gun in a bench rest and several hundred rounds of each weight shot at a target at various rages?

[M_P]

Not personally but you don't need to to see large differences, you can see it yourself by simply shooting a gun with various different weights.

[Ian_Gere]

ErThose bench tests must have been done to find out how safe/unsafe airsoft is when using typical eyepro, otherwise nobody would insure airsoft sites. I'd want to know whether the tests were done using something like a lab high pressure air line so the pressure behind the BB could be adjusted exactly, or simply using real guns. Also whether anyone involved was an airsofter because it seems to me that, if not, they could have forgotten one very important thing which we haven't considered either.

 

There is something which proves beyond a shadow of a doubt that Joule Creep has no effect whatsoever on actual airsoft shots, even if the maths which I was unable to fill in above did somehow come up with a figure that is real world significant, which I think is impossible but let's just say, and that is the fact that it takes more hop up to lift heavier BB's than lighter and the more hop is turned on, ie the more friction applied to the BB, the slower the slower it goes, ie less of its energy is conserved as momentum because it has been lost as heat and sound...

[CaptainSwoop]

I can see how extra weight could improve accuracy down range as any wind gusts wiil have less effect but again we are talking about tiny fractions of a gram in weight.

[M_P]

I can see how extra weight could improve accuracy down range as any wind gusts wiil have less effect but again we are talking about tiny fractions of a gram in weight.

Get a 500 fps rifle on a still day and fire a .2 and a .4, the difference is very noticeable- It doesn't matter how small the difference in mass of the projectile is, it has an impact regardless. Otherwise everyone would just use .12s.

[Airsoft-Ed]

Personally, having used one specific gun for an exceedingly long time using the same set up on the brink of the fps limits, I do believe that Joule Creep is real, I have known guns fire at very close to the limit on a .2 that when chrono'd with .25s are shooting quite a noticable amount higher than the conversion charts state it ought to be.

My ICS L85 was firing at more or less 365 on the dot on the medium tension setting, which is perfect for Skirmish Airsoft's 368 limit, but when visiting most other places that have a 350 limit, I'd have to lower the tension a notch on the spring, which generally put me around the 345 mark.

According to the conversion charts, 350fps on a .2 equates to about 313fps with a .25, but I would see readings in the region of 325/330 with .25s with my L85 - I was losing barely 20fps when I should have been losing around 35/40.

I've brought up the point before that barrel bore plays a part in how conversion charts work, and I think joule creep is basically the same effect happening, but exaggerated. You do gain power by using heavier ammo because more air acts on the shot than it does with a lighter round.

In a tightbore less air can get around the BB, so more of it gets used faster, so to speak, and lighter BBs therefore obviously end up with a higher muzzle velocity.

Put heavier BBs in and there's the same space around the BB for the air to get past, which isn't a lot. So instead of losing the 40fps you lose from a .05mm barrel, in a .01 you instead only lose about 20fps because far less air gets the chance to escape around the bb.

I firmly believe based on personal experience that joule creep does exist and it exists to a noticeable enough level to make use of it.

Additionally, on the topic of effective range I can also say from experience that when you're used to 365fps and you have to drop down to 345, when working at the extent of your effective range, which realistically speaking for me was around 45m, 20fps is the difference between hitting someone in 5 shots, and hitting them in 15.

Obviously the shooter's familiarity will have something to do with it, someone that's used to 345fps will probably be able to shoot better than I can as someone who's used to 20fps more than that, but the fact is, your actual range does change by enough to notice it, and your effective range drops off significantly more than you'd have thought.

Visiting Anzio for the first time I had to deal with my gun being what I felt had become unsuitable because the 20fps power drop changed it's performance characteristics that much that I had to play differently, aim higher, lead further, not engage until targets were quite significantly closer.

If you play as much as I do and you have a gun with variable fps so you can ensure every other factor is the same, you will definitely notice a difference regarding fps and range, and you can physically observe joule creep happening if you have a chrono.

[Chippins]

 

The FPS hard limit for AEG's and all pistols would be 500

I wouold agree if it was enforced that people had to use real cap mags.

[Samurai]

Hi guys,

I'm new to this forum but not new to airsoft and I think I can add some info on this.

 

Here we have FPS limits of 400 for AEGs, 500 for semi-auto only AEGs (20m MED), 600 for bolt-action snipers (20m MED).

Most veteran players downgrade their guns to about 350fps even though we could go for 400. As we say, if you can't solve a problem with 350 then you can't solve it with 400 either. There is only minimal difference in the effective range with those velocities.

 

The 500 fps dmrs have semi only (1 BB in air at a time) and 20m MED. These two limitations are much worse than what you gain in range so veterans playing the DM role usually downgrade below 400. If you are able to shoot 2-3 BB-s with semi auto to a target before the first reaches it, you usually get more hits than with one 500 fps shot.

 

Finally the snipers with 600fps. Experience says that anything above 500fps only shortens the BB's travel time. It doesn't change the accuracy or the range at all. Actually higher fps tends to be a bit less accurate but that's only marginal.

 

Has anyone actually done any controlled testing of different weights? a gun in a bench rest and several hundred rounds of each weight shot at a target at various rages?

 

I've made some tests with different BBs at different fps-s.

The result is: use the heaviest BB your gun can handle (the hopup can spin it). BB quality and weight matters the most to accuracy.

 

In the test I fixed the guns on a workbench table, and used a target on 40m, no wind. I made a lot of shots, counted the hits and misses and averaged the results. Both 350 and 400 fps were tested but on 40m there is no real difference.

 

This is the brand of BB's I use (sorry, only available here) that I found to be the best.

 

Weight: hits

0.20: 76%
0.20 Bio: 80%
0.23: 87%
0.25 Bio: 100%
0.28 Bio: 100%

 

As you see with this test setup I couldn't measure the difference between 0.25 and 0.28 but 0.28 IS more accurate. I should have a bigger yard.

Bio BBs are more accurate due to how they are made, there is no bubble in them so they spin evenly.

 

Other band. No bio. I was using this one before I swithced to the above one.

0.23: 65% (I think this batch was faulty, it should have been higher. Maybe 75-80%)
0.25: 90%
0.28: 95%

 

For my normal AEGs I use 0.28 Bio or 0.30. Hell, I use 0.28 in my 300fps handgun. Never use 0.20 except when chronoing.

People think heavier BBs have shorter range. That is also not true. Heavy BBs retain the kinetic energy better (air resistance doesn't effect them that much) so they actually have the same or slightly better maximum range too. (Check the Airsoft Trajectory Project on this)

 

I hope this helps a bit.

[CaptainSwoop]

Excellent, that's what I was after. Proper evidence.

 

I am persuaded. Heavier BBs are the way to go.

[Unrustle_Thine_Jimmies]

Airsoft trajectory project ftw. Probably one of the best references on airsoft accuracy and range.

[Ian_Gere]

Here we have FPS limits of 400 for AEGs, 500 for semi-auto only AEGs (20m MED), 600 for bolt-action snipers (20m MED).

Welcome to the forums Where are you?

 

Most veteran players downgrade their guns to about 350fps even though we could go for 400. As we say, if you can't solve a problem with 350 then you can't solve it with 400 either. There is only minimal difference in the effective range with those velocities.

That surprises me because, in my own experience, the difference between 345FPS and 365FPS is about 15m effective range and the difference between 365FPS and 425FPS is well over 30m.

 

The 500 fps dmrs have semi only (1 BB in air at a time) and 20m MED. These two limitations are much worse than what you gain in range so veterans playing the DM role usually downgrade below 400. If you are able to shoot 2-3 BB-s with semi auto to a target before the first reaches it, you usually get more hits than with one 500 fps shot.

As far as I understand it, the reason for the difference in restrictions is because BB's fired full-auto leave the muzzle so close together that they can arrive on target literally one behind the other, so the energy they carry could be delivered to exactly the same spot on the target individual, or their eye protection (in completely still air conditions and only when the target person is jammed into a position so they cannot move, ie impossible but necessary to imagine for insurance purposes). I have not heard of a semi-auto restriction of 1BB in the air at a time, but it doesn't sound unreasonable at 500FPS. Nevertheless, even at the extreme when, say, 6 semi-auto BB's are in the air at the same time, nobody could get a grouping at 20+m in which hits overlapped enough to be a concern.*

 

Finally the snipers with 600fps. Experience says that anything above 500fps only shortens the BB's travel time. It doesn't change the accuracy or the range at all.

That is not my experience.

 

It's difficult to know for sure about the maximum range of BASR's because their long range trajectories are steeper than an AEG's, so generally speaking, whether a shot will hit a target at the extreme limit of how far the BB could possibly travel is down to BB weight vs wind conditions, but that isn't the same as determining what that range will be. Perhaps more important is how high the sniper is prepared to bother aiming above the target, which will be partly determined by how wide the objective lens of their scope is. So when we talk about "effective range" it means different things concerning AEG's and BASR's.

 

I adjust my AEG sights for approx 35m range but, in practice, I only use them for L<=>R target acquisition. This is because my instincts will do for elevation at normal skirmishing distances and, because the wind conditions affect the trajectory far more than anything else, at long range, say 60m, that effect is so much that I will get a hit in less shots by walking them onto the target than by using the sights. I set my SVD scope up for 70m and aim down at normal skirmishing ranges. This is so that when I aim at long range it is easier to keep the target individual in view, even if just their head, in the lower half of my scope POV.

 

For eg, with the above scope adjustment, at approx 495FPS w/0.2g BB's but using a 0.3g BB, I aim roughly level with the top of a target's head at 80m to hit him/her in the upper chest, but even though the scope is set for such ranges, the BB disappears up out of the POV of both 32mm and 40mm objective lenses and only returns as it nears the target. This is comparable to how a 345FPS AEG shot aimed at a 60m target behaves to the naked eye. The difference is that aiming the AEG only a little higher will produce a trajectory along which the BB ends up by coasting toward the target, easily deflected by the slightest breeze, ineffective for skirmishing because the target will not feel a hit even if you get one, whereas a BASR shot will not behave similarly until beyond 100m.

 

I do not yet have enough experience of sniping to say for sure whether 100FPS difference in muzzle velocity equates to a useful difference in maximum range. My instinct is that it does matter, although I do believe that air resistance plays an increasingly important role the faster the BB travels. However, if we say that "effective range" is the maximum distance at which you can get a 0.6m grouping with any number of shots (excluding only those BB's which fly off madly due to a defect in manufacture) then the difference between 5 and 6 hundred FPS is massive!

 

During my SVD upgrade it was firing at around 535FPS with its stock M150 spring; at 80m I could hit a particular 10cm-ish knot on a tree 4 out of 5 shots in average air conditions. Now it has an Element M135 spring and fires at approx 495FPS and 5 shots gives me approx 50cm grouping. That is the difference between hitting somebody in cover and, at best, keeping their head down, at worst, giving your position away and compromising your tactics irretrievably.

 

 

Actually higher fps tends to be a bit less accurate but that's only marginal.

That is completely opposite to my experience. I'd be interested to know how you came to that conclusion?

 

I've made some tests with different BBs at different fps-s.

The result is: use the heaviest BB your gun can handle (the hopup can spin it). BB quality and weight matters the most to accuracy.

 

In the test I fixed the guns on a workbench table, and used a target on 40m, no wind. I made a lot of shots, counted the hits and misses and averaged the results. Both 350 and 400 fps were tested but on 40m there is no real difference.

 

This is the brand of BB's I use (sorry, only available here) that I found to be the best.

 

Weight: hits

0.20: 76%

0.20 Bio: 80%

0.23: 87%

0.25 Bio: 100%

0.28 Bio: 100%

 

As you see with this test setup I couldn't measure the difference between 0.25 and 0.28 but 0.28 IS more accurate. I should have a bigger yard.

Bio BBs are more accurate due to how they are made, there is no bubble in them so they spin evenly.

 

Other band. No bio. I was using this one before I swithced to the above one.

0.23: 65% (I think this batch was faulty, it should have been higher. Maybe 75-80%)

0.25: 90%

0.28: 95%

 

For my normal AEGs I use 0.28 Bio or 0.30. Hell, I use 0.28 in my 300fps handgun. Never use 0.20 except when chronoing.

People think heavier BBs have shorter range. That is also not true. Heavy BBs retain the kinetic energy better (air resistance doesn't effect them that much) so they actually have the same or slightly better maximum range too. (Check the Airsoft Trajectory Project on this)

 

I hope this helps a bit.

I'm not sure I really understand all of this bit. I mean, I think everybody knows that heavier BB's travel more slowly but have equal or greater range, so long as the hop will lift them. The issue is what effects any increase in muzzle energy have, if they are significant and, if so, are they desirable in our sport/hobby?

 

Which brand/s of BB's, BTW? As far as I know there should not be bubbles inside any BB's, but I have heard and read people say that it happens. I have never seen a shattered fragment with a smooth curved interior surface which makes me think there was a bubble. When a BB behaves oddly I assume a manufacturing defect and an uneven density due to a bubble seems like a plausible explanation, but since I've never seen one, I wonder if there is something else we are missing?

 

 

*Actually, in tests I conducted on how sturdy mesh is, it took 3 more rounds fired at 320FPS full-auto to penetrate the mesh than the same 0.2g BB's fired from the same gun at the same distance semi-auto. I put this down to the fact that on full-auto some of the BB's shattered, using up energy flinging fragments all over, whereas on semi, at 25mm range, all the rounds delivered all their energy to the same spot.

[Airsoft-Ed]

I think to say higher fps makes guns less accurate is only true if you use light ammo. Or at least, ammo that's too light for whatever the fps is.

A .2 at 500fps won't hit the broad side of a barn, you're going to have to use something like a .3 at least just to stabilise the shot, otherwise it'll spiral off all over the place.

I find that BBs are their most stable at between 290 and 330fps, so I will always use heavier ammo to get the fps into that ball park.

Other than that nothing really strikes me as that surprising, aside from bio BBs being more accurate and better put together. I'd have thought the opposite was true.

I always took bios as being good for nothing other than using at home, because since they degrade the mess they make of my garden will at least be shorter lasting as oppose to practically eternal.

But I assume that some tiny degree of degradation will at some point begin to effect my shot's flight, even if it takes years to set in the fact the possibility is there at all makes me feel like they're a less viable option unless I'm forced to use them by the site regs. Also, most decent BBs that aren't bios won't have air bubbles in them anyway. Blasters are fine, Bastard BBs are fine, Madbull are fine, and they're all I use so I have no worries about that.

[Samurai]

Thanks. I'm in Hungary now but I'll move to the UK in about a month. That's why I joined the forum.

 

The things I wrote about are our experience here. I think a bit specific to our fps rules and restrictions. For example the rule to have only 1 bb in air for the DMRs is to make the marksman rely more on aiming and less on spray and pray. It's not really about the safety.

 

Actually higher fps tends to be a bit less accurate but that's only marginal.

That is completely opposite to my experience. I'd be interested to know how you came to that conclusion?

No lab tests on this, just experience. The snipers here tend to agree on this. Mostly. It is very hard to prove it since you can't change the spring in a bolt action sniper without taking it apart, changing the spring and then putting it together the same way. These are so delicate guns that I don't think those can be put together with the same results twice.

 

Which brand/s of BB's, BTW? As far as I know there should not be bubbles inside any BB's

The only regular BBs I have ever seen or read about that have no bubbles are the SGM 0.29 ones. Madbull 0.40s are quite accurate because the bubble is about in the middle of it. You can use a wire cutter or something similar to cut the BBs and check it.

 

There is no real brand of this BB I'm using. The shop I'm buying from directly imports it from a china manufacturer. But it's actually so good that I'm sure when I move to the UK, I'll still buy this. A few years ago I've used Blaster and that was not good enough. Maybe they improved since then. Then I've used G&G and Marui BBs, they are not bad. I've used Guarder, ICS too but I can't remember how they performed. The old XTreme and Taiwangun.com's own BBs are the worst I've met.

 

Other than that nothing really strikes me as that surprising, aside from bio BBs being more accurate and better put together.

When the first bio BBs came around they were really bad. Inaccurate, uneven, and they started degrading if they came to contact with humidity of the air. If you left the bottle open for a few days, they got bigger and soft.

The current bio bbs are really good. They degrade by the bacteria in the dirt so you can leave them open if you want to. And because the lack of the bubbles they can be amazingly accurate.

 

Again I can only speak my experience and not facts, feel free to experiment and prove me wrong. Except for the BB tests. Those are facts.

[Ian_Gere]

I decided to try an experiment...

[Semi-only]

If you've seen YouTube vids like jet the dessert fox you will notice that there is a rule banning you from shooting people under ten feet I personally find it better and more fun to shoot the shit out of people at 3 ft and don't mind getting hit as well . It might hurt but if you can't take it play some nerf

[CON]

I think 350-400 mark is fine, any higher and injuries would increase, especially at my site where we dont have the bang bang rule.

Maybe for strict milsim games when engagments are generally ranged and its not a mix of players

But at skrims it would be pointless,,, for my site anyway.

 

Although I dont know why its 320 for you...is that just at ur site or a a irish thing?