First up I want to give credit to bakabill for his semi auto Magstrike on ON that provided the original inspiration to have a go at this (and in a round about way, I should probably mention Banshee's Blast-Strike on NH and Lefty's Mega-Strike on ON too).
Basically my situation was that I'd seen Bakabill's Magstrike write up on ON and thought it was worth a crack, then realised I had a only somewhat reliable Rapidfire AS-20 sitting at the bottom of my Nerf cupboard. Thought about it for a day or two and decided bugger it, I'll just pick up another BBUMB and give this a go.
I'm not going to go into any real detail with this as it should be fairly self explanatory, but I am happy to answer any questions.
So to kick off with, we have an AS-20.
Removed the outer shell.
Removed the inner shell.
Close up of the internals for anyone who's interested
Inner shell with all of the components removed.
First phase of dremeling.
First mock up of how it will sit.
The stock release valve/now the BBUMB tank refill button.
Where the tank will fit + the start of the RSBC.
Tank with the check valve attached.
Right, I apparently missed a few photos here but you get the idea. Reducer on the front to the t-piece + 30cm of PETG to make the barrel, PVC pipe from the back to the t-piece to the back of the blaster, small hole cut to accommodate said PVC, screw fitting to close off the back of the RSBC.
Still need to figure out what I'm going to use to cover the barrel as I'm not a fan of the exposed/fragile PETG. Tossing up between just slipping over another piece of PVC pipe and painting it black to match the colour scheme, or whether a recon barrel extension would look any good.
Ranges are what you'd expect from from a BBUMB; consistently hitting 30m. The cool part however is that I'm getting that range with 4 darts, in the space of 3 seconds
1: Unscrew the cap and load four darts.
2: Pump 20 times to fill the stock AS-20 bladder, should give you four shots worth of air.
3: Press the button just above the pump to prime the blaster, pull the trigger to fire.
4: Repeat step 3 up to three more times.
6: Start from step 1 again.