Originally posted by RapidTransit
Correct me if im wrong, but would a properly designed venturi, there always will be an advantage. I just think carbs, without a venturi and how crappy theyd work without em 
Whats going to be used to keep the bolt from nicking the next ball in line?
I also wondered about making the rear tapered and taking from a performance valvetrain using beehive springs, which work well for high RPM's or in this case bps.
But what matters most to move the ball? The amount of pressure or the velocity of air at a certain cfm?
Whats going to be used to keep the bolt from nicking the next ball in line?
I also wondered about making the rear tapered and taking from a performance valvetrain using beehive springs, which work well for high RPM's or in this case bps.
But what matters most to move the ball? The amount of pressure or the velocity of air at a certain cfm?
1)Yes you're absolutly correct, Venturi flow is very effective but particularly only @ low pressures/velocities. Carbs are primes examples of this, they suck w/out venturi flow. At high pressures/velocities, flow head loss becomes expontialy greater (logrithmically i believe)
snd effiecency can go down the crapper with even smooth finishes. Unfortunately frictionless flow is impossible. So at paintball pressures the only time venturi begins to add effective imporvement is in the higher end very LP guns, like the bolt shown earlier in this thread. All a venturiwill do @ high pressures is give more laminar (uniform) flow out the bolt head. Although probably not the best for HP high ROF, That has advantages and leads us to #4...4) Plain old F=ma and momentum balance. A certain amout of air mass @ a certain velocity has t amount of time to deliver x amount of energy. Forget blow forward/blowback/open/closed bolt debates. this is it...period. The main difference betwwen venturi and open is this. Venturi can deliver a more streamlined energy flow/transfer with laminar flow with less gas at higher velocity than a open faced bolt. When critical presuures/velocities are reached, Viscous flow dominates and cfm drops and air is wasted when you crank up the speed dial. Other than that it will have pretty much the same cfm @ lower and midrange pressures as an open face bolt while delivering a more streamlined (laminar) flow. This is the theory behind the Venturi bolt. And from low to high pressures an open face bolt can deliver a constant cfm all day long, just more turbulent, that's all. So I guess I would have to say cfm matters most, that is infact where the momentum is coming from; Mass*Velocity goes pretty much hand in hand with cfm. But as always there's a trillion other factors in the marker that impact bolt performance, including the shooter's style. Okay, maybe only a billion
2) I talking more about the air impacting the ball in the breach. not so much the foamie or the next stacked ball. If you could have equal cfm delivered to the ball through two separate styled bolts but one has more linear momentum and laminar flow, which would be more efficient? Basically same as I just wrote above. The only thing that can be said for sure is that at higher pressures an open faced bolt is gentler on paint.
3) could you elaboarate more on the idea, sounds interesting. What are you getting at? Like a Banana?
. The same is true about modern ported barrels, that the air pressure in front of (and behind) the ball acts @ lower pressure resulting in lower natural turbulence. This method is more modern and better performing way to lower the in-barrel turbulence. 
. I just cant visualize what you mean
How about length, bore, finish, and most importantly color! 
Even the porting is really important to the internal flow & turbulence. Do you think engineers just turn on a hand-drill, close their eyes, and see what kind of porting they can make today? Your second statement is moronic and I would love to see you to back that crap up by playing some kind of tourney w/ a $2.99 eBay barrel. 
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