I changed out the original spring with a spring from a ball point pen. The lightest spring I've been able to find is 2 lb 10 ounces on a trigger spring scale. I'm thinking it's no longer the spring tension issue but the tension of the overall trigger design. I tried shortening the spring and it wouldn't hold the cocking mechanism until I stretched it out but it didn't pull any lighter on the scale so I replaced the shortened spring with another out of the ball point pen pack to be safe. I'm happy with the results over the stock tension but was wondering if anyone else had better luck ?