Easy CO2-powered Squib for Self-contained Blood and Gunshot Special Effects

Step 9 Credits and Comments

First of all, let me say that this entire project was inspired by Crosius' amazing Pneumatic Squib Tutorial, which I consider to be a superior design in practically every way. The CO2 squib came about as I was waiting for the parts I ordered to build 8 of Crosius' version to arrive in the mail, and I started thinking about how to duplicate the effect without any specialized parts, and for less money.
Due to minimum part order requirements for the miniature pneumatic parts, Crosius' design will cost about $120 to build the first one if you don't have any of the parts on hand already, which may not be within the budget of the small theatre or filmmaker. If you need 5 or 10 of them, the cost per unit drops to about $40 each, making the CO2 version not much of a cost savings at all.
Crosius' version is also more flexible (you can vary the pressure to vary the effect), more concealable (especially with a minor mod to the trigger assembly. See the Comments section of the Pneumatic Squib Tutorial for details), and daisy-chainable. If you need multiple squibs, build his design. It's just better.
On the other hand, if you only need one or two and are on a tight time or money budget, the CO2 squib may meet your needs just fine. Enjoy.