Bought an after market mainspring through Gunparts. Their wasn't anything wrong with my original spring which I will keep. I had heard the aftermarket spring was lighter pull and it surly is. I don't have a trigger scale but I would say the weights have been cut in half. The claw is three times longer that on the original which makes putting it in a pieta. But the outcome is worth the struggle. Highly recommend it if you use your 1917 as a shooter.