History first...

Rifle started as 6BR with SSS Competition trigger...no trigger/firing problems.

Rechambered to 6 Dasher. Denting some primers, not igniting them...no other trigger/firing problems.
Had Kevin Rayhill install a new, stiffer firing pin spring.

Went to try it out today and after 2-3 shots, I closed the bolt and it fired the round (no my finger wasn't on the trigger). I'm able to repeat it pretty often opening and closing the bolt quickly. So, the only change prior to the problem is switching to a stiffer firing pin spring (Wolff 32lb).

Before I go messin' around with adjusting the trigger/sear, or swapping out the firing pin spring again, I thought I'd see if there's anything else I should consider or adjust?

Picture below should take you to a video.