Alright, here it is. At first this gun was really cool, not with missiles, but micros. It shot them an amazing distance for it's size, and had a great shotgun effect. However, we don't use micros much in our wars, so its 
tactical value was a bit weak. So, I set off to make it fire stefans. One look at this gun says "PVC." 


Opened up. Pretty simple. 

Disassembled. 

Cut your barrels. Mine are about 4" (this size seems to work with a lot of guns). 

Cut the firing tubes out. Using a dremel, drill, or utility knife, carve out the inside of where they used to be. If you don't really care about a super-airtight seal, skip this and the next few steps and just hot glue and 
duct tape the things on like the slob you are :-p. 

Now carve out the insides of one end of your barrels, as shown. 

Using a utility knife again, cut off the little protruding tabs from the firing tubes. 

Hot glue the barrels in, and give them an electrical/duct tape coating for good luck (hehe). 

No, I did not just clog up the firing tubes with hot glue, that's some thick lubricant. Use a ton of it. 

Put it all back together. I cut off some excess plastic, wrapped the barrels in fom pipe insulation, and coated the handles with electrical tape. 

I also made an ammo holder for megas out of the original bow part. If you wanna store another couple of darts, go ahead with it. But it takes up some extra room. It can always be taken off easily, so your decision. 

Here it is, finished. It looks pretty sweet. To get improved range, just slide two darts down each barrel and use it as a shotgun. If you prefer pull and release over pull and push, add some rubber bands. I can get ranges of about 70 ft from this gun, which is good considering its small size and shotgun effect (indoors it's devastating).

Thanks Gregg!