Your plans seem sound enough. However, everything looks good on paper...its building it thats the problem! I'm not trying to discourage you, far from it, but keep in mind it wont be easy. OKay, here are some tips while your building your rifle:
Looking at your picture, it appears your bolt groove goes all the way back to your sear. This is a big no-no, because that means all the air goes out there when you fire. This happened in my first bolt rifle. To attempt to solve this, you have to put the bolt on the front of a piece of PVC, so when the bolt is all the way back, the groove doesn't go all the way as well. However, this means your chamber is a lot larger than your actual spring movement, so the air slows down as it reaches your barrel, meaning you'd be lucky to get it to fire any distance. I suggest start with a pull back rifle, then give a bolt action a go. /edit: If you have the piece of PVC that extends the bolt your barrel as well, it might work better. This would still make the clip system hard, but i discourage a clip for your first one.
Second, you must remember to allow space for the spring to compress. Although your design isn't to scale, keep that in mind.
Thirdly, a good size for your spring chamber is 1" CPVC and 5/8 OD gasket/O-ring.
Fourth, i assume you haven't built anything yet. My recommendation is that you leave out the magazine for now, in an effort to simplify your project.
Other than that, looks good.
Edited by texmustache, 12 April 2004 - 07:06 PM.