Hi,
I've been skeptical about this, but have been told by many people familiar with springs (some gun related, some not) that coil springs will "settle" with initial use, then pretty much remain the same close to forever.
That said, the most rounds I've put thru an individual gun with the same coil springs is about 115,000 on a Browning O/U trap gun. Though I'd never experienced light firing pin strikes or misfires, I figured it would be a good idea to replace the hammer springs, "just in case." The gun was a Japanese built Citori, and the gunsmith only had springs for the Belgian models. He told me they were interchangeable, but the Belgian springs were probably a bit stiffer and would increase my trigger pull weight a little.
He was right: the first couple of weekends I shot with the new springs, the trigger was a bit heavier. But within a month, about 1000 rds, all had settled in, and the scale I borrowed said the new trigger pull was the same as it had told us the old one was. I haven't gotten too worried about coil springs since. If it ain't broke...
Of course, one can always apply the old racers' rule: anything you have a spare for won't break. Toss a new spring in the kit and go shoot! You might want to treat it with some rust preventative cuz it may live in that box for a long time!
Rick C
