Trigger creepiness, chapter two and some data

Ok, I admit to having the living sh*t annoyed out of me by this low dollar, never-meant-to-be-a-match-trigger POS on the 760

And I'll cop to be more than a little obsessed by it.  

Tonight's misadventures got it much more crisp.

 The Data:

ID of the pump tube: ~.625

OD of the hammer ~.610

OD of the "base" of the spring guide" ~ .605

So the design has some slop in it, probably to facilitate manufactureing and assembly. Just taking the hammer, and moving it thru the slop with my finger tip doenst account for the percieved movement I saw over the week end. The fit of the spring guide in the pump tube is considerably looser than than the hammer in same.

I wrapped one turn of vinyl electrical tape around the base of the spring guide to bring it closer to the ID of the punmptube, and reassembled. It helped, but its still <read this in yer best Bela Ligosi> very creepy

Pulled it apart again, and looked it all over. The hammer showed the obvious point of contact with the sear, and diagnostics over the weekend showed where the sear was worn from sear contact. This made it very clear that the "shelf" the sear locked on to is slightly less than vertical, having a slight lean toward the rear of the gun.

So this means that the very small point of contact on the sear is d r a g g i n g across the face of the "shelf", and the hammer does deflect a minute amount, but not the inches Sunday;s work seemed to indicate. The combination of the two symptons generate the creep.

I forget if Rob or Andy said to reduce the contact of the sear with the face of the hammer. Didnt register till this evening, but that has been promising. I have been trying to see where I could add some set screws to reduce take up and over travel, but the design mostly precludes that. Staring at it some more, I hit on adding a 3/32 or so biit of wood on the clamshell gbehind tha safety to do what the setscrew would have. it stops the sear from engaging the hammer further up on the "shelf"

Tests with that bit in place make the trigger much less creepy and almost crisp. need to figure a way to get a set screw in that spot for some precise adjustments.

And..... I do believe it possible to add a second lever in the trigger chain (ala the B800 pistol) and get some better feel and function.

 

dr_subsonic's pneumatic research lab

the Lunatic Fringe of American Airgunning
Southwest Montana's headquarters for Airgunning Supremacy
Proud Sponsor of team_subsonic