Thanks for the input, everyone
Originally, I thought that this would be a simple little project. Wrong! Maybe this is why the factory hasn't done anything about this issue - they're too smart.
Obviously we considered a range of possible options. The riser breech was rejected as it would either require a new barrel band (more cost), or would leave the barrel supported only by the one breech setscrew (not good for accuracy, in my opinion). Then there's other issues such as ensuring functionality with the HDD and reduced cheek weld (and hence practical accuracy) with the standard QB79 stock due to the increased height of the barrel.
Producing a tank block with a lower drop turned out to be a problem because it would have been much more expensive to manufacture. The barrel band issue also raised it's head. This approach would have been easier if we had accepted the need to modify the front of the wood stock, but I rejected this as other peoples' woodworking skills may be as bad as mine! And the whole concept was to make an adapter that would be simple to install. So woodworking modifications were out.
That left the current adapter concept, which itself proved very challenging to design, but which has the virtue of operational simplicity (just screw it in). Also, many QB78 owners do not want to take their gun to pieces to add an improvement. This makes it easy for them.
So that's why we ended-up where we have. It's a simple solution that allows anyone to use the QB79 and AR2079 with a 9-ounce CO2 paintball tank, as the original design intended.
More comments are welcomed! I'm glad to see some life again in this Forum. For a time, I was worried that it all seemed very quiet...
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