I'm looking through the achive/knowledge base at the article on Arizona style guns and wanted to know what keeps the gun from double firing? Is it the volume of the accumulator or that the magazine gets pessurized at the same time? I like the simplicity of the gun and it looks to work well for my age of sail build. Second, on a .177 caliber gun, what sould the I.D. of the tubing be? How about a good source for tubing? McMastercarr? Grainger? Thanks, Greg.
I've found the Arizona style gun fairly easy to set for single shots. The pin that allows one BB to enter the chamber needs to allow the next BB to slighly enter the chamber. When set up like this the fired BB will always drive the remaining rounds back up into the magazine so only one shot if fired. I have found two situations where the gun will double fire. First, if you leave the valve open too long, the BBs in the magazine will roll back down and a second one will get blown out. The second situation was when I had a straight magazine with a hard cap at the end. In this case, the BBs blown back into the magazine rebounded off the cap rapidly enough that a second BB made it into the chamber before the valve shut and was blown out. I put a small piece of paper towel between the last BB and the cap and it solved my problem. The dampening effect of the paper towel was enough to slow the return of the BBs to the chamber. Then I bent the magazine and the curve took off enough of the rebound that I didn't need the paper towel anymore. 1/4" tubing with a 3/16 ID is OK, but what works best for me is 1/4" OD, 0.180 ID SS tubing. I get mine through Amazon.com and the Small Parts store.
