TNW Firearms will introduce new versions of the Aero Survival Rifle later this year. The new guns will be chambered in 10mm and .357 SIG.
In my testing of 9mm and .40 S&W carbines, the increased velocity (as compared to typical handguns) from the longer barrels can be significant. However, I’ve also seen that velocity increase is widely variable based on the load being measured. It will be interesting to see what kinds of numbers these guns will turn in.
The Aero Survival Rifle is designed to break down easily into a backpack and be used as a survival rifle or camping gun. The rifles use Glock magazines and have a vaguely AR-style look to them.
Rifles can be converted from one caliber to another fairly easily. The upper is the serialized part, so lowers can be purchased and swapped without the need for another trip to your FFL. This is important if you want to convert from one caliber to another that uses different sized mags (9mm to .45 ACP, for example.)