The 'springiness' results from the cocking arms rotating and loading the hammer springs beyond cocked, right? I've noticed that this is one of the adjustments that was typically done better on early and pre-FW era guns. The several pre1913 extractor guns Ive had have openend fully, cocked better and had better triggers than the later and FW models I've had. Earlier regular frame guns had pins in the forend iron that were individually adjusted to the cocking pieces, rather than a single cocking plate. A single plate is obviously not so easily adjustable to find the right thickness that's best for both hammers; it might be nearly impossible. I asked a very good double smith about fixing this problem on one FW I owned and he didn't want to try.