.22lr Bolt Action Test Fixture
I am working on a design for a .22lr bolt action rifle. It will be an aluminum tube receiver with a removable barrel like the Feather AT-9. The design at this point looks very similar to the AT-9, although that is a semi-automatic 9mm. Before working with the actual materials and before the design got too involved, I decided to make a test fixture out of aluminum. I also made some dummy rounds out of aluminum. They appear scratched in the picture because they were cycled a few hundred times before I took the photo. I designed the magazine angle and height based on observations and measurements of various magazine fed .22lr firearms, but it was not identical to any of them. I wanted to test the feeding and extraction before continuing the design.
Originally, I had the barrel too far away from the magazine. The rounds would load if I worked the action fast, but if I slowed it down, they wouldn't make it in. Only the very tip of the bullet was in the chamber when the magazine lips let go of the cartridge and the magazine spring pressure caused the round to go sideways. I moved the barrel about 0.150" closer to the magazine and that corrected the feeding problems. The extraction works fine, although it's only pulling on a non-fired (non-expanded) case and you can see in the video that the last round doesn't eject (I don't have an ejector in the test fixture). I won't know if my extractor design works on a spent case until I have the actual rifle built.
If the still pictures in the video change too quickly, you can pause the video or click on the images below.
Originally, I had the barrel too far away from the magazine. The rounds would load if I worked the action fast, but if I slowed it down, they wouldn't make it in. Only the very tip of the bullet was in the chamber when the magazine lips let go of the cartridge and the magazine spring pressure caused the round to go sideways. I moved the barrel about 0.150" closer to the magazine and that corrected the feeding problems. The extraction works fine, although it's only pulling on a non-fired (non-expanded) case and you can see in the video that the last round doesn't eject (I don't have an ejector in the test fixture). I won't know if my extractor design works on a spent case until I have the actual rifle built.
If the still pictures in the video change too quickly, you can pause the video or click on the images below.