About 4 years ago I started working out what it would take to make a big bore air rifle. The idea was to base it on the Airforce Texan 45. How the cocking and trigger system worked was beyond my scope of understanding at the time. Someone had posted pictures online of a badly damaged Texan 45 and viewing all the parts and watching videos of guys loading and shooting it all started to make sense. Since I design tooling for a living I used CAD to determine how the components in the rifle cycle. Slowly, the parts came together and the right configuration presented itself. The only parts I am not making are the springs and the barrel. The barrel I purchased from a well known air rifle builder in the USA. I had a lot of fun bringing the barrel into Canada at customs. Lots of questions and I am sure I am on file now with the RCMP.
The valve assembly has been made along with all other parts. I fired it the month of October, 2018 I believe it was and seems to work. Still need to fix the barrel in place and that will happen this weekend. From there start on fine tuning parts. The trigger, sear etc are made of stainless steel and will be swapped out for tool steel once I have the design where I want. Need to add a trigger safety and not sure how that will function.
Will post more soon as the build comes along.
Pedro G.
Yesterday I continued threaded parts to extend the tube of the rifle. A coworker allowed me to use his new lathe that he has in his shop. Made most of the parts on my little 7X14 mini lathe and performed all the thread cutting of the tube parts on his lathe.
This morning I drilled, lathed the bore and fitted the tube adapter and end cap of the tube. This all secures the barrel from being shot of the rifle. Now I need to determine a few mounting holes to further secure the barrel to the main tube via the aluminum collars. Much like Airforce Condor arrangement.
Yesterdays pics.
This morning I bored out the adapter to join the two tubes and completed the end plug. Had to determine the depth of the barrel into the plug when fully threaded and setup an indicator to take light cuts until the fit was where it needed to be.
Now that he barrel is secure and cannot be launched out of the main tube, I wanted to test fire the airgun. Not having time to cast a few pellets with the mould I received with the barrel, I cast a round lead blank with a little torch. Then into my mini lathe for turning. Made a simple pellet. Filled the air tank to 1500 PSI and setup a chunk of 2 x 4". As you see in the pictures good penetration but hit a knot in the wood. May have gone further had that knot be present. The pressure was so low after firing that the tank dumped the remaining air.
Next step is planning. Need to make further design changes and start finishing parts. Add a safety and remake the cocking arm, trigger, sear etc. I used materials on hand to prototype, stainless steel was all I had. Trigger, sear and linkages will be made from A2 tool steel.
Thanks for reading.