My .454 SRH (same lockwork as a GP100) had a DA trigger to brag about - or at least I thought so... until I got my first S&W - a 625MG in .45 Colt. I got as far as the hammer spring in my SRH - and reverted back to the OEM due to ftfs - not very desireable anytime, but when you expect a .454 'Crack' and get a wimpy click, it is un-nerving.
I did trade the OEM springs in my 4" SP101, which has a down-sized GP/SRH lockwork, for the kit's weakest components. It popped all primers, too... and, after too much TLC (Thanks to Iowegan's instructions on the Ruger forum!), it became a real treat to shoot. Still cheesy sights and over-sized chambers convinced me I didn't need it, however.
Operationally, the trigger return spring resets the trigger - and holds the takedown plunger in place. Your 'timing' is affected as it would be with a S&W trigger block return spring - stronger means a faster return - and follow-up shot. Jerry Miculek believes in a weak hammer spring, and Federal-only primers, and strong return spring in his speed revolvers.
In any case, I, the S&W fanatic who recently divested himself of his last four Ruger revolvers (Okay, I still have an Old Army... and a MKII.. they were gifts from my wife.), tried current GP100s at different dealers around town - oddly all at $489 - and found them identical in quality, both physical appearance and lockwork action. Sad, huh?
Yes, I agree - this type of QC has been missing. Triggers that don't feel like moving a broomhandle around in a bucketful of sand have been overdue. I first noted the smoother lockwork in the new 4" .44 Redhawk. Having just sold my 5.5" SS .45 Redhawk, I was astonished. The GP100 was even slicker - and lighter. I am impressed... maybe just enough so...
Nope, I just bought a new 627 Pro and a LNIB 64 - I have 4" .38 & .357M covered, I suppose. Still, if they resurrect the partial lugged grey 4" SS GP100, I'm there!
Stainz