Yes, the main reason why I believe the lighter spring gives better shot to shot consistency is because the tests I have run clearly show this to be the case at least for my A5

Here's a theory on how and why the light spring allows better consistency.
As I'm sure you know the front bolt does strike the ball when the marker is fired. The force at which it does so is dependent upon the speed and power that launches the bolt forward which is provided by the drive spring. I think that the bolt strike on the ball effects the exit velocity of the ball to a certain extent. The stronger the spring, the harder and faster the strike, and consequently the greater influence the strike has on the exit velocity.
Conversely, the weaker the spring the less influence the strike has on the velocity. The problem is, the ball is not consitantly stationary in the breech from shot to shot. That is to say the ball has room to move forward against the ball latch or back against the face of the bolt, even side to side. The ball is not necessarily the same distance from the face of the bolt for every shot fired. This could cause the degree of influence the bolt strike has on the exit velocity of the ball to vary from shot to shot. In other words, the bolt force hitting the ball is another inconsistent variable that influences the exit velocity. Minimizing that bolt force with a lighter spring helps to remove that variable from the equation.

Another theory why a lighter spring may provide a more consistent velocity is that a stiff spring may keep the valve open too long allowing some of the air charge to back fill the empty valve body until the valve closes to allow a pressure recharge inside the valve. It doesn't acure to the same extent every valve cycle so the pressure fluctuation in the power tube caused by the back filling of the valve results in velocity inconsistency. A softer spring closes the valve sooner while there is still pressurized air inside the valve resulting in less(or no) back flow, less pressure fluctuation and therefore a more consistent shot to shot velocity. Another inconsistency removed from the equation by use of a softer spring.
Just my thoughts on the subject, maybe not explained as well as could be.
Can't really comment on your proposed low pressure chamber as I have never used a low pressure setup before. However on my setup, the softer spring and higher pressure seem to provide the best shot to shot consistency.
Hope my thoughts on the subject are of some use to you.
Best regards,
Scoreshot

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Excellent post scoreshot

There's some great insight in there.

I see what you're saying about the variation of shot to shot consistancy in relation to the striking of the paintball by the front bolt, however, do you think that the weaker spring would be any more consistant than the stronger spring? I concur with the fact that "more force = more kinetic influence" on the paintball, but i'm not convinced that having either a weak or strong spring will help with consistancy. I think that in both cases, each example of variable force exerted on the projectile would still have somewhat random results, regardless of spring tensility.

The logic behind this opinion centres around something else you have also stated: When running around the field shooting, you are constantly moving when firing your marker. With this movement comes the movement of the paintball inside the breech. For instance, if you were shooting around a left hand corner, you would most likely be laying the marker over to the right slightly (bad shootin habitz, i haz dem . . . sorry) which would cause the paintball to be leaning to the right side of the receiver where the cyclone feed hole is. Leaning the opposite way, the paintball would be against the opposite side of the receiver where it is flat and smooth, with a cleaner transition from breech to barrel. If the paintball was being fired from a fixed stationary position, then maybe the varible of more/less force when the paintball is being struck by the front bolt would have some sort of positive effects. But in the A5's current form this isn't the case.

Correct me if i'm wrong. I just thought i'd add my .02c

Regardless, as I said, great post. I like seeing that other people are just as analytical as I am

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Thanks for a well throughout response HeDsHoTz, and thanks very much for the rep!
You make an excellent observation regarding this theory. I believe there may be yet another aspect to the front bolt/ball interaction and how it is influenced by the spring strength.
The gas discharge event takes place after the initial strike and when the ball has been pushed well past the ball latch into the barrel adapter.
At that moment the ball is either right up against the face of the bolt or it may be just slightly ahead of the bolt depending on the force of the strike.
Ideally, the ball would be right up against the face of the bolt when the gas discharge event takes place. I'm thinking that a stronger bolt strike (heavy spring) is more likely to produce a potentially wider random "gap" between the bolt and ball at the moment the gas is discharged. Less consistent velocity. Granted this effect would be random for any spring used, but it seems to me that a softer more gentle bolt strike (softer spring) would do a better job of keeping the bolt and ball together thru the cycle. More consistent velocity. Just another theory to consider.

Again, thanks for your response, your input and insight is very valuable and much appreciated.
Scoreshot

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Courage can exist only together with your fear.

thanks for the info guys!

in a LPK, the valve is open for a longer time because of the softer spring in the valve. even with a soft drive spring(on a LP valve), it would be open for longer then a hard drive spring(on a HP valve). like this, the ball will not be affected as much by the front bolt because of the lighter spring, but the valve will still be open longer. like you said, the valve being open long would probably make the time its open fluctuate. if this is true, why do all the people i ask who have a LPK say that the velocity became more consistent? most of them were already using a regulator before they installed a LPK. i was told on pbnation that if you use a LP chamber, it will make your shot's velocity more consistent no matter the pressure the marker runs on. this would probably make a stock HP valve with a soft spring more consistent, especially at higher ROF. the LP valve will need a bigger LP Chamber because of the more volume(at a lower pressure) needed to shoot the ball. what do you think? anyone who has used a LPK, can you LMK?

ScoreShot, what your setup? and what are your readings over the chrono with it? mines at +-3fps with a HPA tank and a pps stab with the stock drive spring in.

Edit: my other mods that would affect my consistency more are: superfly front bolt on the DOP pro-seal's aluminum powertube.

I'm by no means a paintball expert. But I do know a little bit about pneumatics. And heres something to consider. If you have a set volume of gas, lets say... 1cubic inch. At 2psi there is double the volume of gas as there is at 1psi.

With that in mind. No matter what pressure you run at you'll still need the same volume of air to move the paintball to 'x' fps. Then you have the variables of temp and paint/barrel match etc that cause volume to be wasted (blown past the ball) and not propel it forward.

When you're running an LPK with a heavier drive spring or High Pressure with a soft spring you're using the same amount of air just in different forms.

Here's my theory on why an LPK is more gas 'efficient':

When you're running standard HP CO2, the marker and the tank are running at the same pressure due to lack of a regulator between them. When you fire, the sudden pressure loss in the valve forces the gas in the tank to want to equalize pressure in the marker to its own. It does this and the temp drops in the tank a small bit also then causing a pressure drop. Now for that split second the entire systems operating pressure is lower. When you fire rapidly, this continues to happen and the pressure flucuates because of all of the pressure equalization and temperature changes occuring in the marker/tank/tombstone/lines causing fluctuations in your shot consistency...

Because the tank and the marker are freely linked together, changes effect the entire system.

When you run a LPK or even standard HP with a reg, you're only allowing 'x' psi to build up in the marker, the lower you can keep that pressure in the marker, the more consistent it will be because no matter what happens in the tank, there will always be more pressure than in the marker, so it's easier for the tank to consistently recharge the marker with the same amount of gas between shots every time.

Maybe this only makes sense to me, but this is the theory in a nutshell...

Look at a waterfall, the flow of water (CO2/N2) over that cliff is dependant on the level of the body of water above it. If that water level (tank pressure/volume) drops, the waterfall flows less water because its always trying to equalize evenly.

Now compare that to a waterfall from a dam (regulator). No matter what the level of water is before the dam (reg), as long as theres enough to flow through the dam (your tank not being empty), it will always flow through at the same rate because of the restrictions inside of the dam (the reg) and the body of water below it (your marker) recieves an ever consistant flow of water (CO2/N2). Dont know if that makes sense but it sure sounds good.

Bottom line is, the more consistant you can feed gas to your marker, the more manageable that gas is for you to predict. Making it able to be tuned to your desired FPS with the least amount of wasted energy.

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Tippmann A5, LPK!, and Egrip (APE 2.0)
PPS 12" Brass .690 - JCS RedHot modded to Gold Power Tube & Hex Bolt - PPS Stab w/ gauge & Hex-Grip - Rap4 Full Cyclone Upgrade Kit w/ Wargear Squishies - HUGE 116/3k Nitro-Duck HPA tank - Spec Ops MP5 Shroud - Rap4 Stock w/ RVA - Tacamo AK Rail - Barska 50mm Red Dot - JCS Duel Trigger

QUOTE KISSArmySoldier: When you run a LPK or even standard HP with a reg, you're only allowing 'x' psi to build up in the marker, the lower you can keep that pressure in the marker, the more consistent it will be because no matter what happens in the tank, there will always be more pressure than in the marker, so it's easier for the tank to consistently recharge the marker with the same amount of gas between shots every time.

Yep! Keeping the supply greater than the demand
will always keep the demand consistently supplied.

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Courage can exist only together with your fear.

do you think having a chamber of air that's more then whats need per shot help consistency? its obvious that at high speeds it would help, but do you think it will help at around 1 or 2bps?

Thanks for your response 27. Good observations! I can see that the wheels in our heads are turnin' now!! I'll get back tomorrow/today with my specs and chrono numbers. It's 1:AM, just got home from work a little while ago and am just too tired to type it all out now.
Thanks again
Scoreshot

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Courage can exist only together with your fear.

Guess I'll need you to restate the question. But I'm hittin' the sack now.LOL
I'll check with you tomarrow/today.
Thanks, Scoreshot

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Courage can exist only together with your fear.

alright, good night. the wheels are turning! lol