I've been doing some tuning on a S%W 625 I bought on the EE a while ago. I did the usual internal polishing - rebound slide, hammer and trigger friction points, etc., and a slightly lighter rebound spring, which resulted in a little improvement and I was able to reduce the trigger pull a little.
I just installed a Brownell's/Wolff standard-weight "Power Rib" mainspring and this has made quite a difference. I don't have a trigger pull gauge but I'd say it has reduced the apparent weight by perhaps 25%, and this is using CCI #300 primers, reputed to be the least sensitive. I have Remington #2 1/2 primers on order - supposed to be more sensitive than CCI - so it will be interesting to see if I can reduce the mainspring weight even further. (I can't use Federal primers as I am using a Lee priming tool and they warn against using Federal primers for fear of accidental detonation.)
ps- Thanks to RHall for the 625 and Dogleg for the advice on drilling out primer flash holes so the primers don't back out when firing "primer-only" loads for testing.
Stuart
I just installed a Brownell's/Wolff standard-weight "Power Rib" mainspring and this has made quite a difference. I don't have a trigger pull gauge but I'd say it has reduced the apparent weight by perhaps 25%, and this is using CCI #300 primers, reputed to be the least sensitive. I have Remington #2 1/2 primers on order - supposed to be more sensitive than CCI - so it will be interesting to see if I can reduce the mainspring weight even further. (I can't use Federal primers as I am using a Lee priming tool and they warn against using Federal primers for fear of accidental detonation.)
ps- Thanks to RHall for the 625 and Dogleg for the advice on drilling out primer flash holes so the primers don't back out when firing "primer-only" loads for testing.