The idea for the BigShock magnum conversion originally started off with a Mega to Elite re-barrel piece I was making for myself. I knew that Worker has already made Mega to Elite dart re-barrel parts so I was just making this piece for personal use. As I was looking at the shape of the BigShock I thought that it might look cool with some sort of barrel extension instead of having just a flat front face.
The picture above shows all the different barrel prototypes and cosmetic changes for the Faux Barrel extension portion. Most of these prototypes were testing for the optimum barrel fit for performance. I tested 3 different inner barrel diameters; 13mm, 13.2mm and 13.5mm.
Using the Caldwell Ballistic precision chronograph I found that all three barrel diameters had no difference in the FPS. The 13mm barrel was a very tight fit and caused lots of resistance when loading in darts. I opted to use the 13.5mm diameter barrel as it provided the easiest reload with little to know resistance. Each barrel also has a portion that constricts a bit at the very inner end of the barrel providing an airtight seal that also retains the dart in the barrel. The Faux barrel extension portion has a very wide bore that gives you lots of room to push the dart in and the transition from the wide faux barrel bore to the actual barrel portion is chamfered to act as a sort of funnel for easier reloading.
The picture above shows the recorded FPS readings for the final version of the Elite Magnum Conversion compared with the Stock BigShock FPS.
The Mega BigShock can fit Retaliator springs so you can further increase the performance with heavier Retaliator spring loads. With the Elite Magnum Conversion and 7kg Retaliator spring installed I was consistently breaking 100 FPS using fresh official Nerf Elite Darts.
The stock BigShock Spring can perfectly nest with the Rebelle Secret Shot Spring so it should be saved if you plan on upgrading a Secret Shot Blaster.