My project gun is a used Bullboss, .25cal. After much modification later, I have it shooting and holding air (unregulated). I did want to 'lock in' the spring tension as there is no real way to index its placement being inside a free spinning hammer. [I could never tell if I was turning the screw searching for the hole in the hammer.]
So I decided to take the action block apart [again] and get to the hammer itself to execute the plan-- --
Using a 4mm hex key I marked where the depth would need to be to keep the same spring position from my test shots over the chrony. Then I removed the factory screw, dropped in a random spacer screw (could be a metal or plastic rod) in the hole so that the distance was the same as before. Applied red loctite and put it all back together.
28gr pellets are now 870fps for 47 ft•lbs. Now I know the hammer screw will not change since I am only using pellets of the same weight and not slugs.
I feel confident that the tune won't come undone.
It was backed off 6.5 turns from the bottom. Any more and cocking became compromised. I did have to adjust the trigger for the different tension placed upon it.
Part of my mod work was removing the shroud and cutting it back. This allowed me to directly thread on a Donny FL Sumo on the exposed barrel. I used an O-ring to take up the space and center the barrel in the remaining shroud tube.
I also threaded an M4 screw on top of the action block to make two points of contact for the top picatinny rail, one that I cut replacing the terrible factory rail. This gave the entire rifle a rigid, stable frame it didn't have before.
I have an idea to add weight to the hammer to test if it will yeild more power.
So I decided to take the action block apart [again] and get to the hammer itself to execute the plan-- --
Using a 4mm hex key I marked where the depth would need to be to keep the same spring position from my test shots over the chrony. Then I removed the factory screw, dropped in a random spacer screw (could be a metal or plastic rod) in the hole so that the distance was the same as before. Applied red loctite and put it all back together.
28gr pellets are now 870fps for 47 ft•lbs. Now I know the hammer screw will not change since I am only using pellets of the same weight and not slugs.
I feel confident that the tune won't come undone.
It was backed off 6.5 turns from the bottom. Any more and cocking became compromised. I did have to adjust the trigger for the different tension placed upon it.
Part of my mod work was removing the shroud and cutting it back. This allowed me to directly thread on a Donny FL Sumo on the exposed barrel. I used an O-ring to take up the space and center the barrel in the remaining shroud tube.
I also threaded an M4 screw on top of the action block to make two points of contact for the top picatinny rail, one that I cut replacing the terrible factory rail. This gave the entire rifle a rigid, stable frame it didn't have before.
I have an idea to add weight to the hammer to test if it will yeild more power.
