Rifle and pistol. This is similar to an old image of mine with a Swarmpede and a Guardian PDW side by side. These RS are the successors of those Stampedes, so it makes sense.
Something that is not obvious is the Swarmfire trigger, the tiny orange button just under the flywheel cage of the RS, which is on top of a stock switch out of a Stampede or the like. A 203-style trigger pack was considered, but the bulk recommended against it. In the absence of suitable small switches and a MOSFET to set up an extremely compact trigger module, I used this support-hand button trigger concept taken from the MASS-1. It's not optimal but it stays out of the way and isn't way too easy to ND.
Close fit. Not compatible with barrel extensions, but why the hell would you need a twist-lock on the muzzle of an assault rifle? That is a RS feature that seems more like a gimmick than like modularity. I can understand the Spectre can, kinda. This doesn't need it though. Shorter is better in a zombie situation.
It's a terrible internals shot but I was up late working on this thing and wanted to get it done, so documentation of the process fell by the wayside and this is all I have. You can see the rear protrusion of the Swarmfire receiver which is as close to the flywheel cage as feasible and touching the front side of the magwell web, and that is after grinding some strategic areas.
When I put a better spring pack in the Swarmy, there will be images of how it disassembles. The Swarmfire is of course hung on the Rapidstrike barrel shroud, but what's more is that the RS flywheel cage has its two front screw bosses on the barrel shroud as well. By removing the 2 rear flywheel cage screws, the whole front assembly (flywheel cage, barrel shroud, Swarmfire) lifts out in one piece.
The battery wiring was rerouted. The harness now has the battery leads attached to the front assembly (connected to the Swarmfire trigger and motor) and a second Deans connector in the magwell that supplies power to the RS.