These are all pictures of the spar after the final gun riveting was completed. I had been very worried about riveting the spar. The bolt method is not as repeatable or reliable as the gun proved to be. It is cheap, and I agree that is will work, but if you have access to a 3x gun, from some friendly neighborhood RV builder or EAA chapter member, abandon the bolt method and back rivet. The bolt method IS back riveting. When using the gun with a back rivet set – with a collar – it is very difficult to screw up.
