I just finished this mod over spring break. Rural King has a great selection of springs and I found two which fit inside the larger central spring around the central peg of the plunger nicely. Gun is VERY loud now though. I thought the AR was the biggest pain, but once I figured out what NerfHaven was talking about, dremmel-ing it out wasn't terribly messy. In my tests, it's registering hits just as solidly as the Beardman's and with comparable accuracy and distance. I'm also using the stock barrel extension and took the AR out of the under-barrel gun. Works nicely for a panic weapon in my opinion. Loses the accuracy of the full gun but will give you a second emergency shot with some good power in a pinch.

IMO, every proper AR removal includes taking out the dart peg in the tube. There is something to be said for keeping the dart out of the plunger (only happened to me once and it is a pain), but as long as that peg is in there you are cutting pressure substantially. If you don't believe me just blow in a tube with the dart peg still in there. Do you feel resistance? Yes.

Blowdart mod proved this. I do agree!