Last year I completed the Buckley inspired rifle and I was hoping to get a chance to increase the feet per second (FPS) on the custom airgun. Earlier this week I set up my chrony and the resulting average was 716 fps with a .22, 14.3 Crosman Hollowpoint pellet.
Taking the gun apart I drilled all the 1/8″ air feed holes up to 3/16″. Resulting velocity increased to a three shot average of 749.
From there I removed the hammer spring and place a 1/4-20 hex nut behind it for a little more preload. Three shot averaged 796 FPS and highest was 805 FPS.
Energy produced prior was 16.4 fpe and 20.5 fpe with the changes. Hoping to increase the FPS to around 900 if feasible.
Calculating the changes with percentages it works out to 12.5 increase in velocity and a 25 percent increase in power!
Given these results I worked out the power at 900 FPS would result in power of 25 fpe. So that will be the goal for spring.
Thanks for reading.