Lancair pilot reported the nose gear collapsed during landing resulting in a propeller strike. Reportedly; a bolt on the drag link had come loose and caused the nose gear to fail.

Narrative

During a VFR landing on Runway XX at ZZZ; upon touchdown I felt a slight shimmy when I eased the nose gear onto the runway. I applied backstick to keep the weight on the nose gear to a minimum after a touchdown speed of 95 kts. The nose dropped as I decelerated through approximately 80-85 kts. The shimmy became more and more pronounced and shortly thereafter; the nose gear collapsed and the propeller struck the runway while the engine was at idle power. The aircraft then decelerated rapidly coming to a stop approximately 20 left of the centerline. I exited the aircraft after securing mags and all electrical equipment. I was not injured.Crash crew promptly responded; but there was no fire to extinguish. The airport operations personnel responded to assess the situation and a mechanic was called to help lift the aircraft. A heavy crane was called by operations and two straps were attached to the base of the prop blades and the aircraft was lifted whereby the nose gear extended and I could assess what caused the mishap. The starboard drag link for the nose gear was detached from the nose strut caused by a missing AN-4 bolt that had apparently worked itself loose. We could not find the bolt on the runway during a FOD sweep of the runway from where I touched down. The bolt was present on the drag link when I performed my pre-flight before takeoff.I had spare hardware on the aircraft so I installed a temporary bolt on the drag link and the aircraft was towed to the ramp area. No further action was necessary to secure the aircraft. There is a Service Bulletin from the manufacturer (SB077-0518) concerning the nose gear drag links that was complied with when I installed the nose gear in Day 0. Additionally; there was a manufacturing defect with my nose gear that I discovered in Day 1 while I was undergoing Phase 1 flight tests. I removed the nose gear and sent it back to the manufacturer; Company X; and the defective gear was subsequently replaced by this manufacturer and shipped to Company Y where my aircraft was located at ZZZ1. The new nose gear assembly was installed by Company Y and I assumed that they torqued the drag link bolts correctly according to the SB; because Company Y was the same company who had informed me about the SB in Day 0 when I installed the previously described defective nose gear. Company Y is a company that provides builder assist on Lancair aircraft; aircraft painting; and annual condition inspections on Lancair aircraft. They are considered to be experts on Lancair aircraft and have a close relationship with Company Z; who manufacture and sell Lancair aircraft kits.