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Here's my take on the reissue of the big bad bow. Unfortunately, I haven't had access to a decent digital camera for a while, but I promise to have good photos up very soon. If there is enough interest I will bother to create a writeup. Flat grey paintjob by the way (if you can't bear the photos).
The breech is simply 17/32" brass within a special cut piece of 9/16" brass. The beauty of this breech is that it does not waste barrel lineage, as the breech slides back over the dart, creating an excellent, clean seal (which requires no shell). It's lubricated with silicon (silicone? wish I understood the difference) lubricant to ensure smooth loading. I may as well mention the barrel briefly now. After browsing for a recommended barrel type for the bbb, I ran into cxwq's suggestion, and stuck with it: 2" of 17/32" at the start nested in 6" of 9/16", all inside of 10" of 19/32". My setup gives the effect of these measurements, though not built quite the same. The breech slider offers that first 2", the breech piece gives the 4" in its size, and then the last 4" is covered by 19/32". What you see in the photos is some sch 80 pvc to protect the fragile brass assembly. At the very beginning of the barrel, there is a piece of dental floss taught tight across the diameter of the barrel, which is crucial to the functioning of my breech system (explained later).
This clip (8 dart capacity) is actually made from a normal tape/cassette case with one end dremeled off. I've had the most luck with "Scotch High Position XSII-S 100 IEC Type II" tape cases since they have the least amount of excess crap on the inside to sand down. After dremeling away at the case and adding some nice black masking tape, I ended up with a perfect clip. Since this is a gravity system, the top dart is actually filled with weights evenly inside to press down on the other darts, and is not a fireable dart. In the photo there is a rubberband over the clip to prevent the darts from rolling out of the open end. This clip can be easily made, and with some velcro, many clips can be easily carried.
I had a bit of fun making this piece, which accepts the clip. It's a cut piece of plexiglass which I then heated with a candle along certain points, and bent, to form the shape you see. I marked the bend points ahead of time in sharpie to know where to heat and form right angles. If you decide to do this, make sure you have acrylic plexiglass and not polycarbonate, since polycarbonate is not a thermal plastic (will just make a big mess if you put it to the fire).
Parts I haven't explained yet
Once I take good photos, I'll be sure to have some detailed internal shots. The way the breech actually works is linked to the 'trigger' half of the gun. There is a length of coathanger (use musicwire in the future) which I carefully bent in several ways, which attaches to the trigger half, and slides along one side of the plunger assembly and out through one side of the gun. This piece is then attached to the sliding breech piece on one side (out of the way of darts), therefore making the breech move when the bbb is cocked. When the two parts are pushed together, the breech opens and a dart drops in; when pulled apart, the slider slips over the dart (which is held in place by the dental floss bit previously mentioned), and is ready to be fired.
Questions welcomed (I've left plenty out).
Edited by PissBacon, 13 October 2005 - 09:49 PM.