My :2cents: The hole in the lower is not a serious issue and as others have pointed out it would be unlikely to pass Tech Branch scrutiny without some mechanism which would limit its functioning to a modified M10/M11 lower. Even with one it might be a tough sell considering the present political climate.
The only reason I didn't spring for a SABRE was the unnecessarily elaborate nature of the design, and the myriad little screws required for assembly/disassembly. Boy, did I get hammered for those opinions when it first came out. As months wore on and reports of other problems arose it confirmed my decision.
A unique upper receiver which uses off-the-shelf AR-15 barrel/barrel extensions, can be field-stripped with ease, and has as many off-the-shelf internals as feasible - especially those prone to breakage, like bolts - would be a stone-cold winner. Select fire capability would be the absolute minty tits.
Price would be dictated by cost plus profit so that should not be the primary consideration, though the lower the price the more units which will sell initially. I say "initially" because the price of a RR, a RDIAS, and even lightning links continue to soar, and when you could have an M10 or M11 upper that would be similar to an M16 for a 10th or even a 5th of the cost of an automatic 5.56 weapon system then a loftier price would become less of a roadblock.
$2,000.00 is probably the tipping point for a lot of folks here, but $3K for something that fits the above requirements would still sell more than enough to pay for all tooling and manufacturing costs plus some profit in the first 9 months. After that the profitability would only increase.
It would probably end up being as game-changing as Richard Lage's MAX series of uppers - and that is speaking volumes.
So...please design, build, and mass manufacture this dream so we can all be happy, the extant supply of 5.56 in the world will dwindle, and you can be filthy rich.
