PBR bow custom back-feeder barrel

This needs 7 extra 4-40 screws, the standard size that Sillybutts uses for his designs (90273A10 I think is the McMaster part number) and a tension spring. I'm not sure where the spring I used came from, it just has to have loops the screws fit in, and be roughly the right length. 

You'll also need a length of 5/8" pipe, I used the leftovers from my bow arms for this, but I don't think the strength or material much matters.

You install the barrel like normal, but I would install all of the custom bits onto it before you put it on the bow, because you'll need access to the screw on the stationary end of the spring.

Install the feeder before you put on the mag stopper, or you might not have room for the screws. 

The pipe should friction-fit into the big piece, but the screw will also push on it, so it'll be fine either way. The mag stopper just slides on, and then the stopper back goes on and gets bolted in place behind it. I just tightened it until it stopped moving, as it just needs to hold the mag stopper. The mag stopper should slide past the feeder, but you don't want much friction or a big gap there.

This loading mechanism is inspired by Matt Yuan's Physics-Defying tube blaster, but given he didn't provide files of any kind and I worked mine from scratch, I don't really consider it a remix (also can't link to it).

It works the same as his does though, where it needs two darts loaded in in order to function, and the back dart acts as the seal for the front dart.

Probably should specify that this is intended only for half-darts, full-length will not work.

I find reaching up with my bow hand to move the lever and then loading a dart in with my other hand to work quite well, you just need a pocket full of darts.

The spring washers are optional, they just helped my screws hold the spring a little better