I'm assuming this will work on the actual Eliminator?
Given the age of this thread, I'd imagine you're already done, but for reference, the mod of the innards should be the same. Given that the packaging seems to be targetting adults, however (factoid: according to the former CEO of Hasbro, the core Nerf demographic is 11-19), it's probably unsurprising that they made liberal use of sonic welding (read: melt the plastic to act like glue) to render the shell less accessible. Below are a rundown of the hurdles to watch for:
First, this guy. A little plastic ring fused around the bottom of the grip. I wedged a knife in and snapped it, but more elegant solutions probably exist. It is fused to both main shell halves along the seam between them.
Next, the grip itself is fused for an inch or three along the front and back. Again, I wedged a knife in and managed to pop the front open. For the back, the seal was harder, and I had to just wrench the halves apart and hope the seam was the weakest point (it was).
Third, to support the handy little sliding dart stowage block in the grip, the halves actually have a heavy metal pin between them near the bottom. It's not fused to either half, but be aware that, once you snap the halves apart, pull them directly away from eachother. Forcing the gun open like a book with the pin still in place may break the plastic.
As a side note, you can see how heavily the back of the grip was fused here...
Okay, not a real 'difference,' but on this particular gun at least one of the screws seems to have been stripped out on insertion. I'm pretty sure this much plastic pulling out means it's not going to go back together nice and tight, and may also mean some of the screws are heat- or chemically-melted into their holes.
Finally, a curious note: exact same plunger geometry, but no mysterious second black disc/washer. Also, I did a check with a strong flashlight- the cavity in the back half of the plunger actually stops at the visible seam, meaning no dead space. If the Reflex IX-1 has a fully hollow plunger, this may make the original Eliminator more efficient pre-modding. I don't have a measuring setup handy, but I could believe I'm getting in the generous tail of the quoted 25' flat pre-mod.
I'll be drilling out the AR on the gun above (front half of the plunger is still fused at the seam
) and trying the barrel mod as soon as I can get to the tools/parts. If I come up with any different results or other improvements, I'll try to post them.