Speaking as a fellow person who thinks "outside the box", I really appreciate the creativity that went into this design. Best wishes on your development journey!I could envision this being a break-barrel design, with the spent disc being ejected by a mechanism similar to the ejector used on a break-barrel shotgun/rifle...$70 for a provisional patent application is peanuts compared to the typical cost of a patent
Bill,Glad to hear you are continuing the project.As for the efficiency, it's quite simple really. You want your plenum as large as practically possible to have the least pressure drop in the barrel as the bullet travels down the barrel. W=(F)x(D)=(PxA)×(Barrel length). So theoretically once the bullet is at the muzzle you want the valve to close and trap the remaining air in the plenum. The air in the barrel is unfortunately lost. You will then require less air from the tank to get the plenum back to the required pressure ( regulated system). In practise however my experiments indicated that closing the valve somewhere midway the barrel had a slight decrease in muzzle velocity ( we are talking around 300m/s velocities here...so close to the speed of sound) but a significant impact on the shot count and the sound of the shot. You could hear the difference between an efficient shot vs a wastefull one.Hope this helps.What did you think of my idea with the 2x90 degree link to emperically measure the loses of the traditional vs inline design?
With a burst disc you are, of course, working with a dump valve.... The larger the valve, in proportion to the barrel volume, the more potential FPE, but the less efficient the gun will be.... I never exceed 50% of the barrel volume with a dump valve, and 25-33% is a lot more common.... Going larger than 50% is chasing diminishing returns.... Here are a couple of examples....My last post was to show why I seldom use a dump valve, the efficiency is low, unless you are going for relatively low FPE....Bob
In theory, the smaller that distance, and consequently the smaller the total port volume, the higher the pressure at the base of the bullet before it moves.... I actually wonder if that is the reason that not retracting the nose of my bolt quite clear of the back of the barrel port gives a slight increase in velocity.... The nose of the bolt is restricting the flow area, but the initial pressure is higher.... resulting in more power....I seat my bullets just ahead of the forward radius of the barrel port....Bob
After reading most of this thread, I have one idea that could well be dumb, but... If you put a tiny rubber o-ring on a slug or a pellet, so it delays the burst and allows pressure to build up behind the pellet, wouldn't it increase power? if you put it close to the end of the pellet, it could roll out of it and fly out of the barrel after the pellet.