[MadMax]

One inventor to another: I get the feeling that this democratic design process is going to find out that reality and public opinion are not going to meet.

Few if any airsofters are hop up designers who have tried their ideas out in materials so our input (mine included) is going to have limited if any bearing on what will actually work. I have some limited experience in prototyping in elastomers, but that's about it. I've never cast a hop up and compared it to other designs so it's pretty hard to provide any learned opinion on your CAD models efficacy in apply spin.

Making and comparing design revisions in a test gun is going to yield far more practical input on your design. I find that in early product design I apply the axiom: "get physical fast". It is very easy to fall in love with early design concepts that seem so perfect as a thought experiment. Once you make something in materials the impact of some of the simplifications you made in your thought experiences becomes more clear and you'll smack yourself upside the head: "What was I thinking?!". Iteration in materials gives understanding far faster than coffee table discussion with those who have never worked in the materials you plan to.

As a comment on your component designs outside of backspin considerations, it does appear that you are designing rubber parts with features that may be too small to practically mould. I find when I CAD small features that it is helpful to pull out a pair of calipers and look at the size of the features that you are modeling. SolidWorks is a great modeling program, but the ability to look at something at a huge scale on a big 24" screen can make impractically small features look feasible. Other features like undercuts can be difficult to demould from your tooling. You may have to post cure parts for quite some time for them to have sufficient strength to be demoulded if you have many small or thin features which wrap around tooling. I think that mould release agent may help with this, but I find that they often get slightly adsorbed into the surface of cast rubber parts. While this ok with many applications, your product quite necessarily needs to apply friction to a pellet. A thin film of demoulding compound adsorbed into your part surface could be problematic.

I also note that some of your designs include thin sections that terminate in a sharp edge. This can present a manufacturing problem where you can't consistently exclude bubbles. Thin sharp terminations can trap bubbles which results in bad parts. Venting and injection points are going to have to be placed to assure flow across these stagnation areas. These tooling features will result in stubs which will have to be cut off.