I hope you post your results, I swapped out to a 19lb spring while I only had 2 misfires on my rifle, they were my error as I assume my primers were not fully seated and I was using ammo i had loaded for a previous barrel. I may also swap back to the 16lb spring and see if I can get by. The 19lb has been working flawlessly for around 200+ rounds but I too can notice a bit of bolt lift difference. It is enough that I roll the rifle occasionally when extracting a spent round. With the 16lb spring I had zero issues with the rifle wanting to roll.Did a brave thing today. Replaced my 19lb spring with the stock 16lb. Will run it in the WAR Rifles PRS match.
Pin and spring are bone dry. Cleaned with carb cleaner and dried in dehydrator. Spring actually creaks when I lift the bolt.
.031" firing pin protrusion.
When I got the rifle, I had fired about 400 rounds with the 16lb spring before I started having issues. I had never cleaned it, and noticed from day 1 that the pin drop seemed "lethargic". I cleaned and installed the 19lb spring and never had an issue. Today after cleaning and drying with the 16lb spring, the pin seems to drop with more aggression than when I first got the Nucleus.
Bolt lift difference to me is very noticeable. With the 16lb spring, I can lift without rotating rifle. With the 19lb spring, I have to have a firm grip on rifle and even then I often break position.
I'm going to test it out a few times before the match, as well as clean/dry immediately before match (and probably after first day).