low pressure mag style

[Jakedubbleya]

Only assumptions in the sense that thats the way it seems to work w/ various scatter plot tests using diferent kinds of barrels.

Also, i was sort of under the impression that that was the consensus among the paintball community. (ive witnessed tests showing similar results myself)

But, I also have to add: A paintball is NEVER stable.

*cough*... (no ****)

[hitech]

... 10" are more accurate than 8" because apparently the ball needs that extra 2 inches to finish stabilizing...

Um...No.

Anything past 8" actually wastes air...

On what marker? Tom has stated that the automag (level 7) needs about 10 inches of barrel to efficiently reach 300 fps. After somewhere around 10 inches in a level 7 marker the pressure drops to far to continue accelerating the paintball. Now, with a level 10 things are different. The pressure behind the paintball is higher, and the pressure when the ball exists the barrel is higher. Tom confirmed this. So, it stands to reason that a longer effective length barrel would increase efficiency. The problem is finding one.

Anyone have a 14 inch effective length barrel in either twist lock or cocker threads?

[hitech]

It seems to me that the simplest idea is the extending power tube piston. In it's retracted state it would be as long as the existing power tube piston. In it's extended state it would be able to stop (or severally restrict) the flow of air from the dump chamber. It's elegantly simple like the level 10 itself and might just work.

[Jakedubbleya]

Um...No.



On what marker? Tom has stated that the automag (level 7) needs about 10 inches of barrel to efficiently reach 300 fps. After somewhere around 10 inches in a level 7 marker the pressure drops to far to continue accelerating the paintball. Now, with a level 10 things are different. The pressure behind the paintball is higher, and the pressure when the ball exists the barrel is higher. Tom confirmed this. So, it stands to reason that a longer effective length barrel would increase efficiency. The problem is finding one.

Id haveto disagree with you there but at the same time sort of give in because i dont have the energy to put a complete report together.

The gun we used at the test was a spyder running at 300 +-2 fps and a little over 300psi.

We used a spyder because the field we were at had just about every barrel in spyder threading.

I admit though that i have heard of tests showing that up to 10" is indeed the point of max accel/efficiency but they seem to be the exception (8" seems to be the standard for spyders and cockers from what ive read), id be curious to see what effect variations in chamber and bolt design have and go further into this... although i think we might just be reinventing the closed/open bolt debate.

Personally i dont see how bolt design or variations from 300-800 psi firing pressure would effect the ball in the barrel because the only way they could is by lettign more or less air get in front of ball rather than behind it during the period the ball is in the barrel. But if you wanted to find out all you woudl have-to do is measure the amount of air coming out in front of the ball on a gun firing 800 psi air and on a gun firing 300 psi air (then closed vs. open/blowback vs blowforward). If the same amount of air is coming out in front of the ball consistantly, then no, bolt design and operating pressure have nothing to do with the most efficient length of a barrel, and vice versa.

[hitech]

I'd have to disagree with you there but at the same time sort of give in because I don't have the energy to put a complete report together.

The gun we used at the test was a spyder running at 300 +-2 fps and a little over 300psi.

We used a spyder because the field we were at had just about every barrel in spyder threading.

You should read Tom's accuracy testing at the top of this thread. Too much there for me to repeat here.

Did you chrono EVERY shot? How many shots did you use?

I admit though that i have heard of tests showing that up to 10" is indeed the point of max accel/efficiency but they seem to be the exception...Personally i dont see how bolt design or variations from 300-800 psi firing pressure would effect the ball in the barrel...

In a 'mag when the bolt is in the forward position there is a path from the dump chamber to the paintball. The bolt stays forward until AFTER the paintball has exited the barrel (confirmed by Tom). As the paintball travels down the barrel air travels from the dump chamber to the space behind the paintball (the barrel), attempting to equalize the pressure in the barrel with the pressure in the dump chamber. The pressure in the barrel goes up and the pressure in the dump chamber goes down. As the paintball travels forward this space gets bigger and bigger. On a level 7 'mag this spaces becomes large enough that the pressure drops enough to stop accelerating the paintball in about 10 inches. On a level 10 'mag, you are starting with a higher pressure, and it NEVER drops enough to stop accelerating the paintball in today's barrels. This is evidenced by the fact that there is a "high" residual pressure in the dump chamber after the marker has cycled. Therefore, if the barrel were longer the paintball could continue to accelerate with air that is now venting out the end of the barrel after the paintball is gone.

[Jakedubbleya]

In a 'mag when the bolt is in the forward position there is a path from the dump chamber to the paintball. The bolt stays forward until AFTER the paintball has exited the barrel (confirmed by Tom). As the paintball travels down the barrel air travels from the dump chamber to the space behind the paintball (the barrel), attempting to equalize the pressure in the barrel with the pressure in the dump chamber. The pressure in the barrel goes up and the pressure in the dump chamber goes down. As the paintball travels forward this space gets bigger and bigger. On a level 7 'mag this spaces becomes large enough that the pressure drops enough to stop accelerating the paintball in about 10 inches. On a level 10 'mag, you are starting with a higher pressure, and it NEVER drops enough to stop accelerating the paintball in today's barrels. This is evidenced by the fact that there is a "high" residual pressure in the dump chamber after the marker has cycled. Therefore, if the barrel were longer the paintball could continue to accelerate with air that is now venting out the end of the barrel after the paintball is gone.

well, if only i knew more about mags BEFORE i posted lol.

But thatd do it... some definite thinking outside the box by tom on that one... no wonder mags are so inefficient tho lol, they need a 30"(guess) barrel to shoot efficiently. But whats the point, nobody uses 30"(conjecture) barrels, and they are no more accurate than 10" ones.

The dump chamber might concievably increase efficiency if there was just less air (high or lp) in the dump chamber (where it would even out the pressure only up to say 10-14")...

ill just shut up now, that was some major ignorance on my part lol.

[SlartyBartFast]

But thatd do it... some definite thinking outside the box by tom on that one... no wonder mags are so inefficient tho lol, they need a 30"(guess) barrel to shoot efficiently.

While you're taking it to the extreme, it must be said that if paintballers weren't such sheep following the latest trend, you'd be able to find properly tuned barrels.

I meanm what's the point of a 12, 14, or 16 inchh long barrel that has porting starting after the first 5-4"?

Best barrels are probably the Lapco ones. J&J has good ones as well.

[SlartyBartFast]

It's elegantly simple like the level 10 itself and might just work.

But I doubt you could replicate the level 10 AND have the extending piston.

[Jakedubbleya]

While you're taking it to the extreme, it must be said that if paintballers weren't such sheep following the latest trend, you'd be able to find properly tuned barrels.

I meanm what's the point of a 12, 14, or 16 inchh long barrel that has porting starting after the first 5-4"?

Best barrels are probably the Lapco ones. J&J has good ones as well.

agreed, i dont use anything but lapco or CP (j&J rocks too of course).

[SlartyBartFast]

I have a design.

Anyone have the dimensions for bolts? I think that was the one thing missing from Tom's "all-inclusive" slugbody CAD file.

Edit:

Nope it was in there!

[ScatterPlot]

But I doubt you could replicate the level 10 AND have the extending piston.

QFT.

[SlartyBartFast]

Hmm. No matter what I sketch it either just won't work, would open up again as the bolt travelled back, or starts looking like a sear tripping Shocker.

If it's efficiency that's wanted, how about decreasing the dump chamber size and increasing pressure? Abandoning the lvl10 vent and upping the pressure to the point where the lvl 10 bolt appraoched lvl7 forces initially.

Tom, what's the max safe pressure that the reg and dump chamber can handle? In other words, just how unsafe is a reg without a safety blow-off?

[Jakedubbleya]

From what i understand the point o this chamber is to keep the pressure in the barrel equal resulting in more velocity correct? What im also gathering is that the chamber is simply releasing too much gas for this to improve efficiency and would only improve efficiency on a very long unported barrel, it is wasted on normal marker barrels, correct? So slarty, why a smaller chamber w/ higher psi? wouldnt that release the same amount fo air? why not just a smaller chamber?

Sry guys just trying to understand this, i am open to castration lol.

[SlartyBartFast]

So slarty, why a smaller chamber w/ higher psi? wouldnt that release the same amount fo air? why not just a smaller chamber?

.....

Sry guys just trying to understand this, i am open to castration lol.

The problem is the current design not only reacts as a regulator, it remains open even after the ball has left the barrel (according to infromation attributed to Tom). Reread hitech's port.

Actually, what I've been contemplating really boils down to trying to turn the current design into a spool valve. Dumping a measured amount of air per shot.

To maximise efficiency you need to turn off the air supply from the dump chamber once the ideal amount of air has been put in the barrel. The 'Perfect' quantity would be such that at the end of the barrel the ball would be travelling at 300fps and pressure would be atmospheric.

But i guess that also brings in the idea of the 'ideal' barrel length. At some point, any if pressurised air isn't cbeing continuously supplied to the barrel, the expanding air is providing little energy to the paintball and simply filling the growing space.

[SteelSoul]

ok been reading this and have some thoughts


Slarty, I think you hit the nail on the head.
A spool valve would solve the problem of blowing extra air after the bolt fired.
If we knew what the pressure requriments of the lvl 10 bolt were couldnt you reg the pressure down to that via a reg then the mag's reg?

lets say that it took 500 psi for the lvl10 to work, and we used a palmer fatty to step the input pressure down to 500. wouldnt that stop some of the extra air that is expelled after the shot. If there was less pressure being dumped into the chamber it would expel less air?


Here is more poo from my head.
what if there was a way to make the on-off close faster that way there would not be as much air dumped into the chamber.


I keep going back lower pressure = more shots per tank. Look at aka markers they are known as super low pressure and have the ablilty to shoot deep into the tank.

If the mag cannot work at a lower pressure to keep the higher rates of fire then forget this idea


Spool valve is the way to go