45 Auto

I bought one and already did these mods and took pictures to post, but you beat me to it. A few other points I have noticed in my mods:

1. There are a number of slots on the side of the plunger tube. I doubt it adds much power, but I covered these with a single piece of electrical tape stretched smooth. The single piece has enough clearance inside the shell that it doesn't rub.

2. After removing the AR, I tried loading the mega darts with elite darts. This does not improve their performance, but rather makes them dive from being too heavy. There is, however one use for doing this...

3. One design flaw I noted is that the sleeve that picks up the darts during loading is rather thin - mine jammed and developed a chip that was chewing my darts. I fixed this by shaving the chip off and sanding the edge, but watch out for it. The darts need to be a bit stiffer, if your darts get smashed at the front, they won't load right, and the blaster will jam. Loading the crushed mega darts with elites will at least allow them to load and fire again (depending on the severity).

Regardless of plunger design, this blaster develops some serious power (it can even leave a red whelp at close range after AR removal). Whilst (as always) its range is not as amazing as advertised, it is actually very accurate at close to mid ranges (for a nerf gun of course).